MODEL J – STYLE G

HERMETIC COMPRESSORS
MAINTENANCE Supersedes: 180.23-M4 (795) Form 180.23-M4 (1298)

MODELS
JG43, JG63, JG83 (SHORT STROKE)
JG44, JG64, JG84 (LONG STROKE)

27599A
 TABLE OF CONTENTS
SECTION I – GENERAL
General Description .................................................................................... 3
Nomenclature .............................................................................................. 3
Physical Data .............................................................................................. 4
Limitations ................................................................................................... 4
Electrical Data ............................................................................................. 5
Threaded Fastener Torques ........................................................................ 6, 7
Gaskets & O-Rings ..................................................................................... 8
Handling Compressor Parts ........................................................................ 8
Rigging the Compressor ............................................................................. 8
Compressor Oil System .............................................................................. 8, 9
Capacity Control System ............................................................................. 10, 11
Analysis of Faulty Compressor Valve Operation ......................................... 11
Ordering Renewal Parts .............................................................................. 24

SECTION II – DIS-ASSEMBLY & RE-ASSEMBLY

General, Venting & Evacuation ................................................................... 12
Warnings ..................................................................................................... 12
Replacing the Oil Pump .............................................................................. 13
Capacity Control Solenoids & Unloaders .................................................... 13
Crankcase Heater ....................................................................................... 14
Compressor Oil Strainer .............................................................................. 14
Suction Strainer ........................................................................................... 14
Oil Level Sight Glass ................................................................................... 14
Removing Discharge Manifold and Top Heads ........................................... 15
Discharge and Suction Valves, Cylinder Sleeves and Unloader Sleeves ... 15
Replacing High Pressure Relief Valves....................................................... 17
Removing Pistons and Connecting Rods ................................................... 17
Installing Pistons and Connecting Rods ..................................................... 18
Removing Rotor .......................................................................................... 19
Removing Bearings and Crankshaft ........................................................... 20-23

27599A

FIG. 1 – 6-CYLINDER MODEL J “G” COMPRESSOR

2 YORK INTERNATIONAL
 FORM 180.23-M4

SECTION I – GENERAL

GENERAL DESCRIPTION
YORK Style G Model J Hermetic Compressors are de- CLATURE). Varying steps of capacity control are avail-
signed to meet air conditioning requirements using R22. able utilizing solenoid valves. (Control of solenoid valves
They are available in 4, 6, or 8 cylinder models in either must be by external device.) Nominal compressor
“short stroke” or “long stroke” versions (See NOMEN- speeds are 1750 RPM (60 Hz) and 1460 RPM (50 Hz).

NOMENCLATURE

COMPRESSOR IDENTIFICATION

Each compressor is identified by nomenclature as

shown below. The nomenclature is stamped on a data
plate which is located next to the oil pump as shown in
Fig. 2. When contacting the factory or ordering renewal
parts, include the complete Nomenclature, Serial Num-
ber, and Date Code as illustrated. Be sure these num-
bers are copied accurately.

LD02975

LD03063

Compressor Series

Style G

Number of Cylinders (4, 6, 8)

No. of Cylinders
4 6 8
3= 3.2" 3.0" 3.1"
Stroke 4= 3.8" 3.6" 3.7"
Number of Unloaders (1, 2, 3)

Motor Size (M, N, P, Q, S, T, V)

Voltage Code:
17 = 200-3-60 46 = 460-3-60 63 = 220-3-50
28 = 230-3-60 50 = 380/415-3-50 64 = 346-3-50
40 = 380-3-60 58 = 575-3-60 70 = 500-3-50
43 = 440-3-50 59 = 190-3-50

Motor Vendor
L = Leroy Smith
S = A. O. Smith
J G 4 3 1 – M 46 S

FIG. 2 – COMPRESSOR DATA PLATE

YORK INTERNATIONAL 3
 PHYSICAL DATA
COMPRESSOR MODEL JG43 & JG44 JG63 & JG64 JG83 & JG84
No. of Cylinders 4 6 8
60 Hz 143 170 201 242 278 331
Nom. CFM Displacement
50 Hz 119 140 168 199 232 273
Bore (Inches) 3-3/4 3-3/4 3-3/4
Stroke (Inches) 3.2 3.8 3.0 3.6 3.1 3.7
Suction Conn. (ODF) 3-1/8 3-1/8 3-5/8
Discharge Conn. (ODF) 2-5/8 2-5/8 3-1/8
Oil Charge (Gals.) 3 3 3
Weight (Lbs.) 1370 1480 1640

LIMITATIONS
VOLTAGE LIMITATIONS COMPRESSOR OPERATING LIMITATIONS

The following voltage limitations are absolute and op- Maximum Compression Ratio 9.5:1
eration beyond these limits may cause serious dam- Maximum Operating Differential (PSI) 325
age to the compressor or motor. Maximum Suction Pressure (PSIG) 95
Maximum Discharge Temp. (°F) 275
NAMEPLATE MINIMUM MAXIMUM
VOLTAGE VOLTAGE VOLTAGE
Superheat (Nominal) (At Compressor) 20°F
200-3-60 180 220
Min. Oil Pressure (Above Suction Pressure) 25 psi
230-3-60 207 253 Maximum Oil Temperature1 160°F
460-3-60 414 506 Maximum Sat. Discharge Temp.2 155°F
575-3-60 517 633 Maximum Ambient 130°F
220-3-50 198 242 Minimum Ambient 0°F
380-3-60 355 415
380/415-3-50 342 440
190-3-50 171 208 1
Measured externally on pump suction boss as shown in Fig. 3.
346-3-50 311 381 2
Motor selection and operating conditions may limit maximum satu-
rated discharge temperature to lower levels.
500-3-50 450 550
440-3-50 396 484

CHECK OIL TEMPERATURE EXTER-

NALLY AT THIS POINT. MAXIMUM
ALLOWABLE TEMPERATURE 160°F.

27601A

FIG. 3 – CHECKING OIL TEMPERATURE

4 YORK INTERNATIONAL
 FORM 180.23-M4
ELECTRICAL DATA
MOTOR LOCKED MAX. MIN. DISCONNECT
RATED
SIZE VOLTAGE PHASE HERTZ ROTOR AMPS DUAL ELEMENT CIRCUIT SWITCH
AMPS
CODE2 A/L PW FUSE SIZE1 AMPACITY SIZE (AMPS)3
200 3 60 202 913 7312 250 253 400
230 3 60 174 794 636 225 218 400
380 3 60 105 480 385 125 131 200
460 3 60 87 397 318 110 109 200
575 3 60 70 318 254 90 88 100
M
190 3 50 177 757 585 225 221 400
220 3 50 157 731 560 200 196 200
346 3 50 98 470 347 125 123 200
380/415 3 50 87 402 297 110 109 200
500 3 50 68 322 238 90 85 100
200 3 60 238 1099 865 300 298 400
230 3 60 207 956 752 250 259 400
380 3 60 124 579 412 150 155 200
460 3 60 104 478 376 125 130 200
575 3 60 83 382 300 100 104 100
N
190 3 50 214 885 712 250 268 400
220 3 50 183 856 635 225 229 400
346 3 50 115 540 400 150 144 200
380/415 3 50 104 471 367 125 130 200
500 3 50 84 377 277 110 105 200
200 3 60 280 1203 950 350 350 400
230 3 60 244 1046 826 300 305 400
380 3 60 144 633 467 175 180 200
460 3 60 122 523 413 150 153 200
575 3 60 97 418 330 125 121 200
P
190 3 50 251 930 776 300 314 400
220 3 50 217 876 709 250 271 400
346 3 50 133 557 412 175 166 200
380/415 3 50 121 501 410 150 151 200
500 3 50 97 386 310 125 121 200
200 3 60 318 1541 1101 400 398 400
230 3 60 275 1340 976 350 344 400
380 3 60 166 806 591 200 208 200
460 3 60 137 670 488 175 171 200
575 3 60 110 536 390 150 138 200
Q
190 3 50 282 1225 908 350 353 400
220 3 50 244 1187 876 300 305 400
346 3 50 155 775 572 200 194 200
380/415 3 50 139 653 482 175 174 200
500 3 50 108 522 386 125 135 200
200 3 60 387 1746 1322 500 484 600
230 3 60 336 1518 1150 450 420 600
380 3 60 204 919 696 250 255 400
460 3 60 168 759 575 225 210 400
575 3 60 134 607 460 175 168 200
S 190 3 50 343 1470 1087 400 429 400
220 3 50 298 1420 1051 400 373 400
346 3 50 189 903 668 250 236 400
380/415 3 50 167 781 585 225 205 400
440 3 50 148 710 526 200 185 200
500 3 50 131 625 462 175 164 200
380 3 60 247 1143 862 300 309 400
460 3 60 210 960 724 250 263 400
575 3 60 168 768 579 200 210 200
T 346 3 50 234 1174 917 300 293 400
380/415 3 50 207 1000 760 250 259 400
440 3 50 184 856 645 225 230 400
500 3 50 163 754 568 200 204 200
380 3 60 280 1271 997 350 350 400
460 3 60 238 1050 830 300 298 400
575 3 60 190 840 664 250 238 400
V 346 3 50 269 1160 950 350 336 400
380/415 3 50 243 1105 875 300 304 400
440 3 50 213 950 721 250 266 400
500 3 50 191 836 656 250 239 400
NOTES: 1. When optional external overloads are used, fuse sizes should be increased to approx. 175% of nameplate amps.
2. Sixth character in compressor model designation (See NOMENCLATURE).
3. Based on National Electric Code (NEC). Switch is rated for isolating duty only – Do not Open Under Load.
YORK INTERNATIONAL 5
THREADED FASTENER TORQUES
AND SEQUENCE

When assembling a compressor or compressor parts,

it is essential to tighten all nuts and screws to their
proper torque, using an accurate torque wrench. Table
1 shows the recommended torques for this compres-
sor. All screws and bolts should be lightly oiled unless
they are intended for use with a sealing compound.
Insert all screws and tighten them lightly. Then, using
the torque wrench, tighten each to its proper torque.

When tightening the screws on the top heads, handhole

covers, oil pump bearing head, motor cover, and ter-
minal block, it is important that the screws be tightened
in the proper sequence. This will help to eliminate leaks
and/or damage to the parts or gaskets. Fig. 4 shows
the recommended tightening sequence.

It is advisable to “double-check” the torque on all ex-

ternal screws before starting the compressor.

LD03653

FIG. 4A – SCREW TIGHTENING SEQUENCE

TABLE 1 – THREADED FASTENER TORQUE (SEE FIGS. 4A AND 4B)
TORQUE
LOCATION ITEM THREAD GRADE
LB. IN. LB. FT.
Motor Protector Term. (Nut)
1
1 No. 8 - 32 UNC — 30 —
Sight Glass 2 1-11/1/2 NPT — — 95-100
Solenoid Valve 3 .375 - 16 UNC 8 — 49-56
Oil Pump 4 .3125 - 18 UNC 8 — 27-32
Valve Assy. Mounting1 5 .375 - 16 UNC 5 — 30
Set Screw (Crankshaft) 6 .375 - 16 UNC — — 30
Connecting Rod (Screw)1 7 .3125 - 18 UNC 5 — 19-22
Connecting Rod (Bolt/Nut)1 8 .375 - 24 UNF — 260 —
Discharge Valve Cage Assy. (Nut)1 9A .375 - 24 UNF — — 53-58 (Pre-1996)
Discharge Valve Cage Assy. (Nut)1 9B .375 - 24 UNF — — 45-48 (1997 & Later)
Access Cover / Top Head 10 .4375 - 14 UNC 8 — 78-90
Motor End Bearing Head 11 .4375 - 14 UNC 5 — 55-64
Pump End Bearing Head / H. H. Cover 12 .4375 - 14 UNC 8 — 78-90
Terminal Block 13 .375 - 16 UNC 5 — 34-40
Terminal Stud (Nut) 14 .4375 - 20 UNF – — 20-25
Stator 15 .4375 - 14 UNC 5 — 55-64
Motor Cover (Screw) 16 .500 - 13 UNC 8 — 119-138
Oil Pressure Relief Cap 17 .5625 - 18 UNF — — 30
Service Valve Scr. Lgth. thru 6" 18 .625 - 11 UNC 2 — 107-123
Service Valve Scr. Lgth. over 6" 18 .625 - 11 UNC 2 — 68-78
Rotor 19 .625 - 11 UNC 2 — 107-123
Heater Clamp 20 .25 - 20 UNC 2 73-83 —
Manifold 8, 6, or 4 Cyl. 21 .375 - 16 UNC 5 — 34-40
Motor Cover (Stud / Nut) 22 .500 - 13 UNC — — 96-110

6 YORK INTERNATIONAL
 FORM 180.23-M4

LD03661

FIG. 4B – FASTENER LOCATIONS ON JG COMPRESSOR

YORK INTERNATIONAL 7
GASKETS AND “O” RINGS

New gaskets and/or “O” rings must be installed each

time a compress or part is removed or the compressor
is dis-assembled. This will assure that the compressor
will function properly when returned to operation. Use
care when installing gaskets so that they are installed
properly. Be sure that any holes in the gasket for oil
passage, etc. are aligned with the matching hole in the
related part or parts. Also, check that “O” rings are not
cut or damaged in any way. Gaskets and “O” rings
should be coated LIGHTLY with YORK “C” oil. Do not
soak gaskets or “O” rings in oil. Also, do not apply oil to
the mating surfaces. Grease must never be applied to
gaskets or “O” rings.

HANDLING COMPRESSOR PARTS 27523A

FIG. 5 – RIGGING THE COMPRESSOR

Internal machined parts of the compressor such as
valves, pistons, and crankshaft, must be protected from
damage due to crushing or scratching. They should be provided with two oil sight glasses (located on the oil
coated with oil, wrapped in clean, tough paper and pump end of the compressor) to permit a visual check
stored in a safe place. of the oil level.

Before reassembling any compressor part, it should During unit operation, the oil level should be adjusted
be thoroughly cleaned by immersing or flushing it with so that oil-splashing is visible between the middle of the
an approved safety solvent and allowing it to dry in air lower sightglass and the middle of the upper sightglass.
without touching any wearing or contact surfaces. Af-
ter it is cleaned, each part should be carefully exam- 1. YORK REFRIGERATION OIL “C” SHOULD AL-
ined to be sure it is free from cracks, flaws, bump marks, WAYS BE USED ON THESE COMPRESSORS ON
burrs or distortions and the part be oiled to prevent 60 HZ APPLICATIONS USING R-22. 5 GALLON
damage due to rusting or oxidation. New clean oil CAN 011-00312
should be applied to the wearing surfaces of any part
just before it is installed. 2. TYPE “H” ON R-134a APPLICATIONS. 5 GAL-
LON CAN 011-00549
RIGGING THE COMPRESSOR
The internal gear type compressor oil pump is designed
When it becomes necessary to remove a compressor to operate with either clockwise or counterclockwise
from a unit or base, proper rigging methods must be compressor rotation. It is directly connected to the
used to avoid damage to the equipment and/or injury crankshaft and is located externally on the pump end
to service personnel. Portable cranes must be of ad- bearing head.
equate capacity and properly positioned and blocked
to prevent tipping or slipping when lifting the compres- Internal passages in the pump end bearing housing
sor. Do not attempt to lift a compressor with eye bolts and compressor housing connect to an internal suc-
threaded into tapped holes in the compressor casing. tion tube which in turn connects to the oil strainer. The
Instead, use approved and well maintained slings as oil strainer consists of a large wire mesh cylinder with
illustrated in Fig. 5. Be sure slings are of adequate sheet metal ends and an internal spring to prevent col-
strength to safely lift the compressor. Compressor lapse of the strainer screen if it should become cov-
weights are shown in PHYSICAL DATA, page 4. The ered with foreign material.
use of chains or cables is not recommended.
LUBRICATION, MAIN BEARINGS, OIL PUMP END
COMPRESSOR OIL SYSTEM & MOTOR END – Oil under pressure leaves the oil
pump and flows internally through the pump housing
The compressor oil system function is to lubricate all to lubricate the pump end bearing.
moving parts.
Simultaneously, oil is fed through internal oilways in
LUBRICATION SYSTEM – See Fig. 6 – The compres- the crankshaft to supply oil to the thrust collar and motor
sor oil supply is contained in the crankcase which is end bearings. An oil relief port machined in the motor

8 YORK INTERNATIONAL
 FORM 180.23-M4

end bearing housing relieves oil pressure back to the in the crankshaft) for each connecting rod bearing.
crankcase through an eductor. The eductor pickup tube
will draw oil from the motor housing, if present. Normal Lubrication of the cylinder walls and piston pins is ac-
oil pressure is approximately 60 psi minimum above complished by the spray from the spaces between the
crankcase (suction) pressure. connecting rod bearings and the cheeks of the crankpin
as some of the pressurized oil leaves these bearings.
The thrust collar positions the crankshaft longitudinally
in the compressor and takes the thrust forces imposed OIL LEVEL
upon the shaft. Radial grooves for oil are provided on
the inner or thrust surface which is in contact with the The compressor oil level must be maintained between
crankshaft shoulder. the middle of the upper and middle of the lower sight
glass at all operating conditions.
LUBRICATION, CYLINDER WALLS, CONNECTING
ROD AND PISTON PIN BEARINGS – Oil under pres- At part load operating conditions, it is not abnormal for
sure is conducted through drilled oilways in the crank- the oil level to be in the lower sight glass. Whereas
shaft to the crankpins. The crankpin is provided with one running the compressor at full load will tend to return
radially drilled hole (which connects with the drilled oilway more oil to the crankcase.

LD03662

FIG. 6 – LUBRICATION PATHWAYS

YORK INTERNATIONAL 9
 CAPACITY CONTROL SYSTEM
Adjustable capacity control of the YORK Model J Style at the control panel. Other unloading measures may
“G” compressor is accomplished by preventing (block- be taken in response to features written in the control
ing) the suction gas from entering the suction plenums software such as high motor current safety. These fea-
of the compressor. Some cylinder banks are never tures will be described in the particular chiller IOM.
equipped with unloaders. This is to ensure a definite
minimum flow of cool refrigerant gas at all times for The pressure difference created by the suction stroke
motor cooling. One unloader controls flow to one cylin- forces the unloader piston up, uncovering the recessed
der bank, with two cylinders per bank. opening which allows the suction gas to flow through
the port and into the cylinders. The cylinders are now
The unloader mechanism consists of a solenoid valve loaded.
mounted on the outside of the compressor housing, an
internal piston, and internal gas passage ways. The When wiring a standard 6 cylinder compressor, the
system is actuated by means of high pressure dis- capacity control solenoid valves (LDSV) should be
charge gas applied to the top of the unloader piston. wired so the solenoid No. 2 is energized first and sole-
noid No. 1 is energized last. (See Fig. 8) They should
On YORK Chillers and condensing units, normal ca- be de-energized in the reverse order. This will assure
pacity control steps are made in response to water tem- that the compressor cylinders load (and unload) in the
perature or suction pressure setpoints as programmed proper sequence.

LD03654

SUMMARY OF OPERATION
LOADED UNLOADED
SOLENOID DE-ENERGIZED SOLENOID ENERGIZED
GAS PRESSURE APPLIED GAS PRESSURE APPLIED
TO SUCTION PLENUM TO UNLOADER PISTON
UNLOADER PISTON UNSEATED UNLOADER PISTON SEATED
(UP), FLOW PATH OPEN (DOWN), FLOW STOPPED

FIG. 7 – CAPACITY CONTROL OPERATION

10 YORK INTERNATIONAL
 FORM 180.23-M4

NOTE: On YORK, 6-cylinder compressors cylinders 3 & 4 8-cylinder compressors, on YORK Millennium YCA
are permanently loaded cylinders and have no un- chillers, cylinders 1 & 2 are permanently loaded cyl-
loading solenoids. If “optional” unloading is supplied, inders and have no unloading solenoids. If “optional”
cylinders 1 & 2 are the first cylinders to load while unloading is supplied, cylinders 3 & 4 are the first
cylinders 5 & 6 the last to load. This provides three cylinders to load, cylinders 7 & 8 the next to load.
steps of compressor loading/unloading. Unloading This provides 3 steps of loading/unloading. Unload-
occurs in the reverse sequence. In the “standard” ing occurs in the reverse sequence.
loading/unloading scheme where the compressor has
2 steps of loading/unloading, the wiring to the unload-
ing solenoid for cylinders 1 & 2 is unconnected, ef-
fectively making 1 & 2 permanently loaded cylinders.

NUMBER OF CAPACITY REDUCTION STEPS (%) CAPACITY REDUCTION STEPS (%) LD03675

CYLINDERS STANDARD OPTIONAL

4 100, 50 100, 50
6 100, 66 100, 66, 33
8 100, 50 100, 75, 50, 25

FIG. 8 – CYLINDER UNLOADING STEPS FOR JG RECIP COMPRESSORS

ANALYSIS OF FAULTY COMPRESSOR VALVE 5. The operator should feel the heads periodically to
OPERATION, PREVENTATIVE MAINTENANCE check for hot spots or one particular head which is
running hot. If this condition occurs, it is an indica-
The operator soon becomes accustomed to the sound tion of broken or leaking valves within that bank of
of the compressor when it is running under normal con- cylinders. A large temperature difference of 20°F
ditions. Any unusual noise within the compressor should or more between adjacent cylinders may indicate
be investigated immediately. damage, and the unit must be shut down to pre-
vent complete failure.
External indications of trouble within the compressor
are as follows: If leaking or broken valves are suspected, the head
1. When operating on suction pressure control, long should be removed and the valves should be exam-
“on” cycles with short “off” periods may indicate leak- ined for breakage.
ing or broken compressor valves, rings or both.
NOTE: Permanently loaded cylinders are not equipped
2. A definite rise in temperature of the discharge gas
with unloaders (See Fig. 8). This prevents the
may indicate defective suction or discharge valves,
possibility of overheating, since a definite mini-
or a leaking relief valve or both.
mum volume of cool refrigerant gas flows
3. Failure to pull down is a possible indication of a bro- through the compressor at all times during op-
ken suction or discharge valve or both. eration, regardless of load conditions.
4. Unusual pressure gauge readings.

YORK INTERNATIONAL 11
 SECTION II – DISASSEMBLY & REASSEMBLY
GENERAL 6. Dismantle only the part of the hermetic compressor
necessary to correct the fault.
Service on these compressors should be performed 7. Never open any part of a hermetic compressor
only by qualified service personnel, trained in the ser- which is under vacuum; be sure there is some
vice of this type of equipment, and equipped with the pressure inside the compressor. If the compressor
proper tools and familiar with their use. is opened while under a vacuum, moisture laden
Before opening a compressor for repairs, the following air may be drawn into the system and rapid corro-
paragraphs should be thoroughly checked to aid in lo- sion of internal machined parts may result. The re-
cating and correcting the trouble: frigerant is an excellent cleaning agent and will re-
move any natural protective coating from the iron
1. Check the compressor oil level (See page 9). or steel, leaving the raw metal exposed.
2. Check the refrigerant charge to be sure the system 8. Internal machined parts of the compressor such
is fully charged. The unit sight glass should be clean as valves, pistons, and crankshaft must be imme-
and dry. diately protected as they are removed from the
3. Be sure the faulty operation of the unit is caused by compressor. See HANDLING COMPRESSOR
the compressor and not some other part of the unit. PARTS, page 8.
Unit safety and operating controls should be 9. Before removing the cylinder heads, each head
checked for proper operation as explained in the should be match marked in relation to its position
SERVICE INSTRUCTIONS included with the unit. on the housing. When re-installing a head, line it up
4. The voltage at the compressor motor must be within with the discharge manifold and bolt the head to
the limits shown on the unit data plate and page 4. the manifold before bolting the head to the com-
5. Check for a burnout in the motor windings. This may pressor housing.
be evidenced by discoloration of the compressor 10.When assembling a compressor or compressor
oil or by a burnt odor. A further check for motor burn- parts, it is essential to draw all nuts and cap screws
out would be to use an ohmmeter and check if the to their proper torque, using an accurate torque
windings are grounded, or check for an open circuit wrench. See THREADED FASTENER TORQUES
between the motor terminals. These are an indica- & SEQUENCE, page 6.
tion of motor burnout.

WARNING
Before disassembling any part of the J Compressor, be sure the following
Safety Precautions are read and observed.

HANDLING EVACUATION AFTER REPAIRS

When performing service on the compressor it may be During the compressor repair procedure, the crankcase
convenient to remove it from the unit base. If so, refer and oil should be examined for the presence of metal
to RIGGING THE COMPRESSOR, page 8. particles. This would indicate wearing of parts within
the compressor. New oil should be charged into the
DISCONNECT ELECTRICAL POWER compressor using the oil charging valve. (See PHYSI-
CAL DATA)
Before attempting any service on the compressor, all
disconnect switches must be locked out and tagged to The compressor should be given a thorough leak test
prevent accidental starting of the compressor and/or as explained in instruction Form 55.05-NM.
electrical shock.
If the compressor was open for only a few hours, it
VENTING THE COMPRESSOR BEFORE REPAIRS should be evacuated to a pressure of 300 microns us-
ing a quality vacuum pump and following procedures
Before opening the compressor for repairs, the pres- outlined in Form 55.05-NM.
sure within the compressor must be relieved. Close the
suction and discharge stop valves, loosen the pres- If the compressor was open for more than 24 hours,
sure tap next to the adjusting stem on the suction stop the compressor should be completely dehydrated; then
valve, and relieve the pressure in accordance with EPA evacuated to a pressure of 300 microns following the
guidelines. procedures outlined in Form 55.05-NM.
12 YORK INTERNATIONAL
 FORM 180.23-M4

REPLACING THE OIL PUMP CAPACITY CONTROL SOLENOIDS & UNLOADERS

If it becomes necessary to replace the oil pump, a com- Normally, the coil is the only part of the solenoid valve
plete new pump assembly should be installed. To re- that requires replacement. To replace the coil, proceed
place the oil pump, refer to Fig. 9 and proceed as fol- as follows: (See Fig. 10)
lows: 1. Remove the conduit and the wires from the sole-
1. Remove the oil pump cap screws and pull the pump noid valve.
assembly out of the bearing head. 2. Remove the screw from the top center of the valve
2. Install the new oil pump assembly using a new gas- and remove the coil.
ket. Be sure that the flat end of the pump drive shaft 3. Install the new coil. Use caution when reconnecting
engages the slot in the end of the compressor crank- the conduit to avoid placing stress on the valve.
shaft. Stress on the valve may deform the stem and cause
3. Tighten the pump cover cap screws evenly by draw- the valve to malfunction. Reconnect the wires.
ing down opposite and alternate pairs.
If the solenoid valve must be replaced, proceed as fol-
lows:
SLOT FOR OIL PUMP
DRIVE SHAFT 1. Remove six screws from the valve plate.
2. Remove valve from compressor housing.

If the unloader piston must be replaced or serviced,

proceed as follows:
PUMP DRIVE SHAFT 1. Insert screw into the threaded hole on top of the pis-
ton.
2. Remove piston.
3. Remove button screw, flat washer, and gasket on
OIL PUMP the bottom of the piston.

CAP SCREWS & Assembly and installation is the reverse of disassem-

LOCKWASHERS bly and removal.
GASKET

23359A

FIG. 9 – COMPRESSOR OIL PUMP

.3125 - 18 UNC
SOLENOID CAPACITY CONTROL CAPACITY CONTROL THREADED HOLE FOR
POWER CABLE SOLENOID VALVE SOLENOID PISTON PISTON REMOVAL

27524A

27527A

FIG. 10A – CAPACITY CONTROL SOLENOID FIG. 10B – UNLOADER PISTON

YORK INTERNATIONAL 13
CRANKCASE OIL HEATER

The crankcase heater is located on the oil pump end of

the compressor. The heater is located within a well in
the compressor casing; it is not in direct contact with
the refrigerant or oil. To replace the heater, remove the
conduit and disconnect the heater wires. Pull the heater
from the compressor (See Fig. 11).

When installing the new heater, coat it with heat con-

ductive compound (YORK Part No. 013-00898).

OIL STRAINER 27601A

CRANKCASE HEATER
The compressor oil strainer does not contain a flare
fitting in the line between the strainer and the compres- FIG. 11 – CRANKCASE HEATER
sor crankcase. The one-piece line is rolled into a hole
in the compressor crankcase and therefore is not readily
removable in the field.

GASKETS
REMOVING THE SUCTION STRAINER

The compressor suction strainer is located in the mo-

tor housing cover just under the suction stop valve. (See
Fig. 12) To clean and replace the suction strainer, pro-
ceed as follows:
1. Remove the four bolts which hold the suction stop valve
to the motor housing cover.
SUCTION
2. Pull the suction strainer out of the housing and clean STRAINER
with an approved safety solvent or install a new SCREEN
strainer if required.
3. Replace the suction strainer using new gaskets. Note
that two gaskets are used; one between the suction
stop valve and the suction strainer, the other between
the suction strainer and the compressor housing.
4. Bolt the suction valve in place, making sure that it
seats separately. 23365A

REPLACING THE OIL SIGHT GLASS

Compressors are equipped with 2 plug type sight FIG. 12 – COMPRESSOR SUCTION STRAINER
glasses located on the pump end of the compressor.
(See Fig. 13) If they become broken or damaged in
any way, they must be replaced. Proceed as follows:
1. Drain the oil level below the sight glass that is to be REMOVING THE DISCHARGE MANIFOLD
replaced. AND TOP HEADS
2. Remove the damaged sight glass(es).
There are two different types of cylinder covers. Cylin-
3. Clean the threads in the housing and on the new
ders with unloading have a thin flat access cover. This
sight glass with an approved safety solvent.
type of cover also has a small dimple on its underside
4. Apply LOCTITE to the threads of the sight glass and to accept a roll pin mounted in the compressor hous-
screw it into the compressor housing using a socket ing. The second type of head is thicker with no provi-
wrench. Do not overtighten as this may crack the sion for accepting the roll pin. This type of head con-
glass. nects to the discharge manifold. Access covers are not
5. Fill the crankcase with clean oil. connected to the discharge manifold.

14 YORK INTERNATIONAL
 FORM 180.23-M4

out the inner discharge valve plate, discharge valve

and springs.
6. Clean, dry and oil all parts. Inspect the valves for
wear and replace, if necessary.
NOTE: Torquing of the center screw/nut is critical.
7. Assembly is the reverse of removal.

INSTALLING CYLINDER SLEEVES

To install the cylinder sleeves, refer to Figs. 14, 15,

27601A
and 16 and proceed as follows:
1. Carefully lower the cylinder sleeve over the piston.
OIL LEVEL SIGHT GLASS

Push the cylinder sleeve down until it enters the hole in

FIG. 13 – OIL LEVEL SIGHT GLASS AND LEVELS the lower compressor deck. Do not force the cylinder
sleeve. The lower end of the cylinder sleeve is cham-
fered to facilitate compressing the piston rings and
entering the compressor deck. Guide the sleeve
To remove the discharge manifold and the compressor
squarely into the housing and rotate it as it is being
cylinder covers, proceed as follows:
lowered. If the cylinder sleeve is properly seated in the
1. Disconnect the discharge manifold from the com- housing, it should not bind but should spring up slightly
pressor top head and remove the top head from the due to o-ring compression. On Style G, O-rings are used
compressor. only on cylinders that have the ability to unload.
Before removing the cylinder head, each head should
INSTALLING SUCTION AND DISCHARGE VALVES
be match marked in relation to its position on the hous-
ing. When reinstalling a head, line it up with the dis-
Helical coil springs used in discharge valve assemblies
charge manifold before bolting the head to the com-
should be replaced every 5,000 - 7,000 hours on nor-
pressor housing. Be sure to use proper tightening se-
mal chilled water (40°- 50°F LWT) air conditioning ap-
quence as shown in Fig. 4.
plications. Process applications, units operating at
higher-pressure ratios such as low temp brine (20°-
REMOVING THE DISCHARGE AND SUCTION
39°F LWT), and units operating under high ambient
VALVES AND CYLINDER SLEEVES
conditions (ambient temps above 115°F) should have
more frequent maintenance intervals.
NOTE: Mark the cylinder sleeves, discharge valves
and suction valves with a marker so that they
To install the suction and discharge valves, refer to Figs.
can be reinstalled in their original location.
15 and 16 and proceed as follows:
To remove the valve assemblies and cylinder sleeves, 1. With the spring pocket side of the suction valve plate
refer to Figs. 14, 15, and 16 and proceed as follows: up, assemble the suction valve springs in the pocket
and set the suction valve in place.
1. Disconnect the discharge manifold from the com-
pressor top head and remove the top head and ac- 2. To hold suction valve and springs firmly in place
cess cover from the compressor. during installation, two sheet metal clips should be
placed over the suction valve plate and suction valve.
2. Remove the four cap screws which secure the dis-
These clips may be ordered from the Factory –
charge valve cage assembly to the housing, then lift
YORK Part No. 064-03447.
out this assembly. The inner discharge valve plate,
the discharge valve, and the discharge valve springs 3. Assemble the discharge valve cage assembly.
will come out with the cage as an assembly. a. Insert the discharge valve springs in their recesses
3. Slip the fingers inside the suction valve plate and in the valve cage and set the discharge valve in
under the suction valve. Lift off the suction valve place making sure valve is not pinched.
plate, the suction valve and suction valve springs. NOTE: Torquing of the center screw/nut is critical.
4. Lift the cylinder sleeve out of the compressor hous- (See Table 1, page 6 and Fig. 15B.)
ing. b. Insert the discharge valve screw through the in-
5. Disassemble the discharge valve cage assembly. ner discharge valve plate and the discharge valve
Remove the locking nut and center screw. Then lift cage. Then bolt the assembly together using the
self locking unit.

YORK INTERNATIONAL 15
 RAISED HEAD FOR
CYLINDERS WITHOUT
RELIEF VALVES (2) UNLOADER OPTION

DISCHARGE VALVE
CAGE ASSEMBLY
(1996 - CURRENT)

28950A

FIG. 14 – SUCTION AND DISCHARGE VALVES AND RELIEF VALVES

CYLINDER
SLEEVE

SUCTION
VALVE
ASSY
28953A

FIG. 15B – DISCHARGE VALVE CAGE ASSEMBLY

DISCHARGE VALVE 28954A 1996 - CURRENT
CAGE ASSEMBLY

FIG. 15A – CYLINDER SLEEVE ASSEMBLY

SUCTION
VALVE
WAVE SUCTION
PLATE
SPRINGS (2) VALVE

28952A

FIG. 16 – WAVE SUCTION VALVE ASSEMBLY 664-44291-000 (1998 - CURRENT)

16 YORK INTERNATIONAL
 FORM 180.23-M4

INSTALL THE VANE ASSEMBLIES ON CYLINDER 2. Unscrew the leaking relief valve and screw in the
4. It is important that the suction valve not be pinched new valve.
during reassembly. The following steps are recom- 3. Reassemble the top head and the discharge mani-
mended. fold.
a. The piston in the respective cylinder should be
close to the bottom of its stroke. REMOVING PISTONS AND CONNECTING RODS
CAUTION: Never rotate the crankshaft when one To remove the pistons and connecting rods, refer to
or more piston and connecting rod as- Fig. 17 and proceed as follows:
semblies are in place unless the related
cylinder sleeve or sleeves are in their NOTE: The width of the connecting rods at their large
proper position in the compressor hous- end is greater than the inside diameter of the
ing. If this caution is not observed, seri- cylinder sleeve. Before a piston and connect-
ous damage could occur. ing rod assembly can be removed from the
b. Place the suction valve plate, with suction valve compressor housing, the cylinder sleeve must
clipped in place, on the cylinder sleeve. Using one first be removed. Then the piston and connect-
hand, hold the suction valve plate firmly against ing rod assembly can be pulled outward from
the cylinder sleeve, but do not push the cylinder the compressor.
sleeve down against the housing. With your free 1. Remove the suction and discharge valve assem-
hand remove the valve clips. A distinct click will blies. Allow the cylinder sleeve to remain in place in
be heard as the clips are removed, if the valve is the housing.
seated properly.
2. Remove the crankcase hand hole cover plate(s).
c. Holding the suction valve plate in place on top of
3. With the cylinder sleeves in place, rotate the crank-
the cylinder sleeve (do not allow the sleeve to slip
shaft to a position that will permit ready access to
down against the compressor housing) place the
the connecting rod bolts to be removed. Loosen the
discharge valve cage assembly on top of the suc-
nuts and remove the lower half of the connecting
tion valve plate. Insert two cap screws through
rod bearing. Note the identification number stamped
holes in diagonally opposite corners of the dis-
on the half-bearing just removed.
charge valve cage and tighten them “finger-tight.”
4. Using care to make certain that the upper half of
d. Push the discharge valve cage, suction valve plate
the connecting rod bearing remains in place on its
and cylinder sleeve down firmly against the com-
crankpin, rotate the crankshaft to the point where
pressor housing. Insert remaining cap screws and
the piston is very near the top of its stroke.
tighten all caps screws to their proper torque. See
Table 1, page 6. 5. Remove the cylinder sleeve.
5. Use new gasket when installing the compressor ac- 6. Lift out the piston and its connecting rod. Note that
cess cover and top heads and reconnect the dis- the identification number stamped on the upper half
charge manifold to them. of the rod bearing, matches the number on the lower
half of the rod bearing. These numbers should AL-
WAYS match.
REPLACING THE HIGH PRESSURE RELIEF VALVE
NOTE: Never rotate the crankshaft when one or more
The high pressure relief valve is screwed into the up- piston and connecting rod assemblies are in place
per machined surface of the cylinder bank under the unless the related cylinder sleeve or sleeves are
top head to relieve any abnormally high discharge pres- in the proper position in the compressor hous-
sure back to the suction side of the compressor (See ing. If this caution is not observed, serious dam-
Figs. 8 and 14). It is factory set to open at 375 psi dif- age could occur. Make certain also that when
ferential pressure. If leakage of the valve is suspected, the bottom half of the rod bearing has been re-
replace. moved, and it is necessary to rotate the crank-
shaft, that the upper half of the rod bearing does
To replace the high pressure relief valve when the com- not leave its proper place on its crankpin.
pressor is not open for repairs or inspection, proceed 7. Remove piston assemblies ONE AT A TIME, repeat-
as follows: ing the above steps 3 through 6 for each piston
1. Disconnect the discharge manifold from the proper assembly. Proceed to step 8.
top head and remove the top head. 8. Remove the piston pin retaining rings.
CAUTION: DO NOT use any thread locking sealer 9. Push piston pin out of the piston.
on the high pressure relief valve.
10.Remove the piston rings.
11. Clean, dry and oil all parts.
YORK INTERNATIONAL 17
INSTALLING PISTONS AND CONNECTING RODS position. Check to see that the numbers on the two
halves of the bearing are matched and that they are
To install the piston and connecting rod assemblies, on the same side of the connecting rod. Apply a few
refer to Fig. 17, and proceed as follows: drops of oil to the crankpin. Insert the piston and
1. Each piston is equipped with two piston rings. When connecting rod assembly through the cylinder bore
installing the rings, use copper or brass strips under and carefully position the upper half of the connect-
the rings and spread the rings only enough to slide ing rod bearing on its crankpin.
them down over the piston. Insert the cylinder sleeve. (Refer to INSTALLING
NOTE: Piston rings are tapered and must be installed THE CYLINDER SLEEVES).
correctly. The wider part of the ring must be 4. Install the lower half of the connecting rod bearing
down. The top surface of the ring is stamped as described in step 3 above. Tighten the screws
with a dot (See Fig. 18). (or nuts) evenly to the proper torque. (See Table 1).
2. Set the piston with its top surface down on a bench. Hand turn the crankshaft to be sure there is no bind-
Insert the small end of the rod into the piston and ing. Install all piston assemblies, turning the shaft
slide the piston pin into position. The pin is a sliding after each rod is installed, to be sure that no binding
fit into the piston and rod. Install the retaining rings exists.
in each side of the piston. Bearing surface of the 5. Make sure that the compressor crankcase is clean.
connecting rod, piston, and wrist pin must be well- Install the crankcase hand hole cover plates. Fill the
oiled prior to reassembly. crankcase to the proper level with new oil.
3. Cylinder sleeves and piston assemblies, when re- 6. Reinstall the suction and discharge valves and the
used, should be installed in their original locations compressor top head and covers making sure they
in the compressor housing. are in their original locations and reconnect the dis-
Remove the lower half of the connecting rod bear- charge manifold and top head, using new gaskets
ing, allowing the connecting rod bolts to remain in as required.

ROD

BOLTS

CAP
28951A

Replacement rods must match the remaining rods in any one unit, i.e. long stroke with long stroke, short stroke with short stroke. Drilled rods
for wrist pin lubrication (1997 and newer) may be mixed with non-drilled on R-22 applications. Drilled rods are required on all applications that
use POE type oils, such as R-134a and R407C.

FIG. 17 – CONNECTING ROD

18 YORK INTERNATIONAL
 FORM 180.23-M4

1. Remove the cap screws that hold the suction stop

valve to the motor cover. Remove the suction
strainer screen and gaskets.
2. Disconnect the power wiring from the motor termi-
nal bolts.
3. Mark each terminal bolt with the correct lead num-
ber. (Ex. 1, 2, 3, 7, 8, 9)
4. Mark each protector terminal screws with correct
numbers. (Ex. S1, S2, S3)
5. Remove the terminal box and loosen the terminal
plate.
6. Remove the nuts from the terminal bolts and the
LD03154

FIG. 18 – PISTON RING INSTALLATION protector terminal screws and push these down
through the holes in the terminal plate.
7. Support the main body of the compressor using a
TAPPED CAP SCREW
crane or other suitable method. Loosen, but do not
PULLER
HOLES STATOR remove, the cap screws and nuts and bolts that hold
FLAT the motor cover to the compressor housing. Insert
WASHER guide pins (1/2" – 16) into 2 of the screw holes be-
LOCKWASHER
ROTOR fore removing the cap screws. Remove the motor
cover, taking care not to damage the stator wind-
ings.
8. Remove the cap screw, lockwasher and flat washer
that hold the rotor to the crankshaft.
9. Insert 2 cap screws (9/16" – 12) or similar item into
the trapped holes in the end of the rotor.
10.It is not advisable to attempt to remove the rotor
without using the rotor mandrel (YORK Part Num-
ber 364-27273). Screw the rotor mandrel into the
end of the crankshaft and slide the rotor into it.
11. To reinstall the rotor or to install a new rotor follow
steps 7, 8, & 9 in reverse order.
12.Reinstall the motor cover using a new gasket. Be
sure motor cover is properly located on the com-
pressor housing.
13.Pull all power terminals and overload connectors
up through the terminal box opening.
23074A
14.Be sure to place a new terminal block gasket in
position before inserting the power terminal and
FIG. 19 – MOTOR END OF COMPRESSOR overload protectors into the terminal plate.
15.Reinstall the terminal bolts and overload protectors.
Be sure the terminal bolts are reinstalled in the cor-
REMOVING ROTOR rect hold (1, 2, 3, 7, 8, or 9). Refer to Fig. 20 to be
certain all gaskets, washers, seals, etc. are installed
It is necessary to remove the rotor in order to remove properly.
the crankshaft and/or motor end bearings. Also, if it 16.Reinstall the terminal plate, terminal box, power
becomes necessary to replace the rotor or stator, both wiring and cover.
rotor and stator must be replaced. To remove the rotor,
17.Replace the suction strainer screen, gaskets and
proceed as follows:
stop valve.

WARNING
Be sure electrical power to unit
has been disconnected.

YORK INTERNATIONAL 19
REMOVING BEARINGS AND CRANKSHAFT Note that the back-up plate and the split plates must
be installed from the inboard end of the bearing.
Pump End Bearing 5. Apply clean oil to the outside surface of the new
bearing and to the inside portions of the bearing head
To remove the pump end bearing refer to Fig. 21 and into which the bearing is to be pressed.
proceed as follows:
6. Using the bearing removal tool as shown in Fig. 23,
1. “Match-mark” the bearing head and compressor Detail B, pull the bearing into the bearing head, tak-
housing. ing care that the bearing enters the bearing head
2. Remove the hex flange screws which hold the bear- squarely. Note the “split” in the bearing should be at
ing head to the housing and remove the bearing the top of the bearing head. Continue to pull the
head. bearing into the bearing head until the bearing is
3. The YORK Bearing Removal Tool (Part Number 364- 0.15" below the surface on the inboard head.
37260) is required to remove the bearing from the 7. Reinstall the bearing head using a new gasket. Be
bearing head (See Fig. 22). sure the gasket and bearing head are properly
4. Using the bearing removal tool as shown in Fig. 23, aligned with the oil passages. Tighten the hex flange
Detail A, pull that old bearing from the bearing head. screws to the proper torque.

ITEM
DESCRIPTION
NO.
1 Screw - 7/16 - 14 x 2 (16 Req’d)
2 Lockwasher - 7/16 (4 Req’d)
3 Washer, Plain - 7/16 (16 Req’d)
4 Bolt, Terminal (6 Req’d)
5 Gasket, Terminal Bolt (6 Req’d)
6 Washer, Terminal Block (12 Req’d)
7 Nut, Hex (18 Req’d)
Screw, Protector Terminal (2 Req’d Style G)
8
Screw, Protector Terminal (4 Req’d Style G)
Terminal, Overload (4 Req’d Style G)
9
Terminal, Overload (8 Req’d Style G)
10 Washer, Plain (4 Req’d Style G)
11 Seal, O-RIng (4 Req’d Style G)
12 Washer Terminal (8 Req’d Style G)
13 Lockwasher (4 Req’d Style G)
14 Nut, Hex (4 Req’d Style G)
15 Block, Terminal
16 Gasket, Terminal Block
LD03665
17 Washer, Plain (6 Req’d)
FIG. 20 – MOTOR TERMINAL PLATE DETAIL 18 Lockwasher

20 YORK INTERNATIONAL
 FORM 180.23-M4

Motor End Bearing in the second bearing should be turned 90° to either
side. Continue to pull the bearings into the head until
To remove the motor end bearings, refer to Fig. 24 and they are 1/32" below the end surfaces of the bear-
proceed as follows: ing head.
1. Drain the oil from the compressor and remove the 9. Reassemble the compressor by following steps 1,
crankcase cover plate, the motor cover, and the ro- 2, 3, 4, and 5 above in reverse order. Be sure that
tor, following procedures described in the applicable the oil pressure regulating relief valve is at the bot-
sections of this manual. tom of the compressor.
2. Using suitable timber, support the crankshaft inside
the crankcase.
3. Remove the cap screws that hold the bearing head OIL PASSAGE
assembly to the compressor housing. (TO UNLOADERS)

4. Screw the rotor mandrel (YORK Part No. 364-37273)

into the end of the crankshaft and pull the bearing
head out onto it. Use of the mandrel aids in prevent- OIL
ing damage to the stator windings. PASSAGE
(FROM SUMP)
5. The motor end thrust collar will possibly come out
with the bearing head. If it does not, pull it off the
crankshaft. Examine the thrust collar and replace if
BEARING
necessary. A roll pin prevents the thrust collar from
turning with the crankshaft.
6. Using the bearing removal tool as shown in Fig. 25,
Detail A, remove the old bearings from the housing. GASKET
Bearings are removed one at a time in a similar
manner from opposite ends of the bearings head.
7. Apply clean oil to the outside surface of the new
bearings and to the inside portions of the bearing
head into which the bearings are to be pressed.
8. Using the bearing removal tool as shown in Fig. 26,
Detail B, pull the bearings into the bearing head one BEARING
HEAD
at a time from opposite ends, taking care that the
bearings enter to bearing head squarely. Note the
“split” in one bearing should be at the top; the “split”
28949A

FIG. 21 – REMOVING PUMP END BEARINGS

LD03156

FIG. 22 – BEARING REMOVAL TOOL (PART NO. 364-37260-000)

YORK INTERNATIONAL 21
 LD03663

FIG. 23 – PUMP END BEARINGS

RELIEF VALVE -
MUST BE INSTALLED BEARING
AT BOTTOM OF
COMPRESSOR
BEARING HEAD

23071A
FIG. 24 – MOTOR END BEARING ASSEMBLY

LD03664
FIG. 25 – MOTOR END BEARING
22 YORK INTERNATIONAL
 FORM 180.23-M4

Crankshaft EXPANDING
MANDREL STATOR
The compressor crankshaft can be removed from ei- (029-13597)
ther end of the compressor depending on which end is
more accessible. To remove the crankshaft, proceed
as follows:
1. Drain the oil from the compressor. Remove the crank-
case cover plates, discharge manifold, top heads,
suction and discharge valve assemblies, pistons and
connecting rods, motor cover, and rotor following
procedures outlined previously.
2. Using suitable timber, support the crankshaft solidly
inside the crankcase.
3. Determine from which end the crankshaft is to be
removed and remove the bearing head from that end
of the compressor.
4. Screw the rotor mandrel (YORK Part No. 364-37273)
into the end of the crankshaft and remove the motor
rotor.
5. Using two people, carefully remove the crankshaft
from the compressor.
6. If the crankshaft was removed through the pump end,
the thrust collar will probably remain in place in the
compressor on the motor end. Be sure that this thrust
collar is properly positioned on the roll pin before
reinstalling the crankshaft. Check thrust clearance,
after reassembly for allowable range of .013 - .038".
7. Reassemble the compressor by following the above
procedure in reverse order.

WHEN INSTALLING STATOR THESE GUIDE

Removing The Stator (See Fig. 26) GASKET PIN
SURFACES MUST BE ABSOLUTELY
CLEAN! NO VARNISH, DIRT, BURRS,
Normally it should not be necessary to replace the sta- CHIPS, ETC.
tor unless a complete motor failure occurs. If it becomes
necessary to replace the stator, a new rotor must also FIG. 26 – REMOVING THE STATOR
be installed. (Always install stator before rotor). To re-
place the stator proceed as follows: 5. Install the expanding mandrel (YORK Part No. 029-
13597) inside the stator, and adjust the mandrel so
1. It is advisable to remove the compressor from the
that it is tight within the stator.
unit before attempting to remove the stator.
6. Using a hoist or crane attached to the mandrel, re-
2. Drain the oil from the compressor. Remove the
move the stator from the housing being careful not
crankcase cover plates, discharge manifold, top
to damage the windings. Do not rest the stator on
heads, suction and discharge valve assemblies, pis-
the windings.
tons and connecting rods, motor cover and rotor,
using procedures outlined previously. 7. When installing a stator, the surfaces where the sta-
tor rests on the housing must be absolutely clean,
3. The compressor should now be placed in a vertical
free of varnish, dirt, etc. (See Fig. 26).
position, on the pump end.
8. Using the mandrel and guide pins, lower the stator
WARNING into position, being careful not to damage the wind-
Be sure the compressor is supported and blocked ings. Be sure the stator is properly positioned with
adequately so that it does not tip or fall during the respect to motor leads.
disassembly procedure. 9. Remove the hoist, mandrel and guide pins. Insert the
4 cap screws and tighten them to the proper torque.
4. Remove the 4 cap screws that hold the stator to the 10.Reassemble the compressor using procedures de-
compressor housing. Insert guide pins (7/16 - 14 x scribed in the respective sections of this manual.
9") into 2 diagonally opposite holes. (Largest stator Use a new gasket between the motor cover and
weight approximately 300 lbs.) compressor housing.

YORK INTERNATIONAL 23
 ORDERING RENEWAL PARTS

All compressor parts are designed and manufactured for a specific application.
They are selected to withstand the pressures normally associated with compres-
sor operation. The substitution of non-standard parts is not authorized as these
parts could cause serious damage to the compressor or operator. Parts should be
replaced with genuine YORK Renewal Parts. The Renewal Parts Manual Form
180.23-RP4 lists replacement parts for these compressors. When ordering parts,
be sure to follow all instructions included in the Renewal Parts Manual.

P.O. Box 1592, York, Pennsylvania USA 17405-1592 Subject to change without notice. Printed in USA
Copyright © by York International Corporation 1998 ALL RIGHTS RESERVED

Form 180.23-M4 (1298)

Supersedes: 180.23-M4 (795)