CDS Directional

Control Valve

Assembly and Test

Manual
 CDS Directional Control Valve Assembly and Testing Manual

Using this manual

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© 2005 Sauer-Danfoss. All rights reserved. Printed in U.S.A.

Sauer-Danfoss accepts no responsibility for possible errors in catalogs, brochures and other printed material.
Sauer-Danfoss reserves the right to alter its products without prior notice. This also applies to products
already ordered provided that such alterations aren’t in conflict with agreed specifications. All trademarks in
this material are properties of their respective owners. Sauer-Danfoss and the Sauer-Danfoss logotype are
trademarks of the Sauer-Danfoss Group. Detroit Diesel®, Cummins®, and Caterpillar® trademarks are properties
of their respective owners.

Front cover illustrations: F101 489, F301 112, P104 394

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Contents

INTRODUCTION Overview ........................................................................................................................................................... 4

General instructions ...................................................................................................................................... 4
Safety precautions ......................................................................................................................................... 5
Unintended machine movement ....................................................................................................... 5
Flammable cleaning solvents ............................................................................................................... 5
Fluid under pressure ................................................................................................................................ 5
Personal safety ........................................................................................................................................... 5
Symbols used in Sauer-Danfoss literature............................................................................................. 6
Required tools ................................................................................................................................................. 6

ASSEMBLY Assembly instructions .................................................................................................................................. 7

Centering types............................................................................................................................................... 9
Spring centered assembly (A) .............................................................................................................. 9
Three position detent assembly (B) .................................................................................................10
Spring/detent detent assembies (C,D&E) ......................................................................................11
Spring center/float detent assembly (J) .........................................................................................13
Hydraulic kickout (F) ..............................................................................................................................14
Spring center assembly (G, H, I)..........................................................................................................14
Auxiliary valves ..............................................................................................................................................15
Load check ......................................................................................................................................................16
Handle assembly ..........................................................................................................................................17
Joystick assembly .........................................................................................................................................18
Alternate joystick assembly ......................................................................................................................19
Cable assembly .............................................................................................................................................20
Oil and test conditions ...............................................................................................................................22

TESTING Adjusting pressure settings ......................................................................................................................22

Main relief valve ......................................................................................................................................22
Work port relief valve ............................................................................................................................22
Adjusting main/port relief valves......................................................................................................22
Leakage testing .............................................................................................................................................23
Work port leakage ..................................................................................................................................23
Load check leakage ................................................................................................................................23
Function testing ............................................................................................................................................24
Spring Center Function .......................................................................................................................24
Detent Functions ....................................................................................................................................24
Float Functions ........................................................................................................................................25
Pneumatic Function ..............................................................................................................................25
Hydraulic Function .................................................................................................................................25
Solenoid Function .................................................................................................................................26
Three Way Spools ....................................................................................................................................26
Backpressure test .........................................................................................................................................26

TROUBLESHOOTING The valve leaks...............................................................................................................................................28

It still leaks .......................................................................................................................................................28
Sticky spool ....................................................................................................................................................29
Relief doesn’t work.......................................................................................................................................29
Cable binds .....................................................................................................................................................29

APPENDIX A Appendix A Testing certification form ..................................................................................................30

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Introduction

OVERVIEW This manual provides information and procedures for the assembly of a new CDS valve
group using the following guidelines:

The specification sheet (CDS build tool and CDS order form) is compiled by the
distributor and assigned a number provided by Sauer-Danfoss. The order form is then
sent to Sauer Danfoss (preferably electronically [FAX]) and reviewed and approved by
the Sauer-Danfoss Technical Support Team (TST) or customer service (CDS) assigned
personnel. The specification sheet will then be logged into a master file. Once it is
determind that the distributor wants S-D to start providing this assembly, a Sauer-
Danfoss part number will be assigned.

After final testing, the test certification, (Appendix A), is to be completed by the
assembly/testing personnel. A copy of the certification must be sent to the TST at Sauer-
Danfoss, Easley, SC.

Before, during and after the assembly/disassembly of new CDS groups, absolute
cleanliness and care must be observed with regard to internal and external parts of the
units concerned. Use non-volatile, petroleum based solutions for cleaning valves and/or
modules. Replace all parts considered likely to cause malfunction during subsequent
testing and report nonconforming product to Sauer-Danfoss (TST). Replace all loose
O-rings (without exceptions) with new O-rings. Lubricate all moving parts with hydraulic
oil before assembly. Lubricate all O-rings with petroleum jelly. Lubricate all detent and
spring centered accessories with LUBRIPLATE 730-1 or equvaliant.

Refer to this manual and the CDS Specification sheet for module designations, item
numbers, spare parts numbers, tightening torques, etc., whether assembling new groups
or making repairs.

Refer to Directional Control Valves Technical Information Manual 520L0564 for more
detailed information including order codes and specifications.

GENERAL INSTRUCTIONS Follow these general procedures when assembling CDS stack valves.

e Keep it clean
Cleanliness is a primary means of assuring satisfactory valve life, on either new or
repaired units. Clean the outside of the valve thoroughly before assembly. Take care to
avoid contamination of the system ports. Cleaning parts by using a clean solvent wash
and air drying is usually adequate.

As with any precision equipment, all parts must be kept free of foreign materials and
chemicals. Protect all exposed sealing surfaces and open cavities from damage and
foreign material. If left unattended, cover the valve with a protective layer of plastic.

l Lubricate moving parts

During assembly, coat all moving parts with a film of clean hydraulic oil. This assures that
these parts will be lubricated during start-up.

d Lubricate all O-rings and gaskets

Lightly lubricate all O-rings with clean petroleum jelly prior to assembly. If the stack valve
is being repaired, it is recommended that all O-rings be replaced..

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Introduction

SAFETY PRECAUTIONS Always consider safety precautions before beginning a service procedure. Protect
yourself and others from injury. Take the following general precautions whenever servicing a
hydraulic system.

Unintended machine movement

W Warning
Unintended movement of the machine or mechanism may cause injury to the technician
or bystanders. To protect against unintended movement, secure the machine or disable /
disconnect the mechanism while servicing.

Flammable cleaning solvents

W Warning
Some cleaning solvents are flammable. To avoid possible fire, do not use cleaning
solvents in an area where a source of ignition may be present.

Fluid under pressure

W Warning
Escaping hydraulic fluid under pressure can have sufficient force to penetrate your skin
causing serious injury and/or infection. This fluid may also be hot enough to cause burns.
Use caution when dealing with hydraulic fluid under pressure. Relieve pressure in the
system before removing hoses, fittings, gauges, or components. Never use your hand
or any other body part to check for leaks in a pressurized line. Seek medical attention
immediately if you are cut by hydraulic fluid.

Personal safety
W Warning
Protect yourself from injury. Use proper safety equipment, including safety glasses, at all
times.

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Introduction

SYMBOLS USED IN  WARNING may result in injury  Tip, helpful suggestion

SAUER-DANFOSS
LITERATURE  CAUTION may result in damage to  Lubricate with hydraulic fluid
product or property
 Apply grease/petroleum jelly
 Reusable part
 Apply locking compound
 Non-reusable part, use a new part
 Inspect for wear or damage
 Non-removable item
 Clean area or part
 Option – either part may exist
 Be careful not to scratch or damage
 Superseded – parts are not
interchangeable  Note correct orientation

 Measurement required  Mark orientation for reinstallation

 Flatness specification  Torque specification

 Parallelism specification  Press in – press fit

 External hex head  Pull out with tool – press fit

 Internal hex head  Cover splines with installation

sleeve
 Torx head
 Pressure measurement/gauge
 O-ring boss port location or specification

The symbols above appear in the illustrations and text of this manual. They are intended
to communicate helpful information at the point where it is most useful to the reader.
In most instances, the appearance of the symbol itself denotes its meaning. The legend
above defines each symbol and explains its purpose.

REQUIRED TOOLS The following tools are required to build a CDS control valve :

Hand tools:
Hex head wrench: 3/32, 1/8, 5/32, 1/4
Sockets: 3/8 deep well, 11 mm, 13 mm, 17 mm, 1 inch, 22 mm, 32 mm
Phillips and flat head screw driver
Torque wrench: 3/8 drive 0-68 N•m [0-50 lbf•ft].

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Assembly

ASSEMBLY The valve is to be assembled in accordance with the CDS stack valve order form.
INSTRUCTIONS

Following assembly steps include installation of optional relief valves and optional
control components.

The assembly sequence for CDS stack valve groups is as follows :

1. Ensure that all parts required, according to the completed CDS stack valve order
form are present. Unpack and inspect all parts for damage and cleanliness. Ensure
that all parts are free of nicks, burrs, contamination etc.

2. Install a nut and lock washer on one Install inlet section first
end of each tie rod. Guide tie rods
through holes in each section (inlet
section first).

3. Place all lubricated O-rings in their

respective grooves in the different
modules before installing them.

4 Install shims between each section,

one per tie rod.
Install shims between each section

Install shims between each section

including Inlet and Outlet sections.

6. Install the basic valve section

module(s) indicated on the order
form against the inlet section.
Ensure that the machined surface
of the next section faces the O-rings
of the previous section.

This will ensure that the O-rings do not fall out during assembly

The first spool listed in model number is closest to the inlet section.

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Assembly

7. Install the outlet section against the Install outlet section

last basic valve section.

8. Install lockwashers and nuts on end

of tie rods.

Install the lock washers and nuts hand

tight so the sections can’t separate and
allow the O-rings to fall out of place.

9. Lay the stack down on its mounting

feet. Adjust washers and nuts so Torque tie rods
tie rods stick out equal distance on
either side of valve.

10. Tighten tie rod nuts incrementaly in

staggered order.

Tie rod nut torque:

• CDS 60 is 16-18 N•m [13-15 lbf•ft] ,
• CDS 100 is 25-27 N•m 18-20 [lbf•ft]
using a 1/2 inch socket.

11. Check each spool to ensure free movement of all sections. Any binding or sticking
in spools is unacceptable. If binding/sticky spools are present, disassemble the stack
and inspect for cause. Replace parts as required.

Spool movement will have a slight drag from the O-rings. Be careful not to shift the spool
end past the O-rings. Shifting spool end past the O-rings may damage the O-rings.

12. The spools are pre-installed into the spool bores of each valve section at the factory.
Each spool is matched to its housing. Do not interchange spools. Inter-changing
a spool from one section to another, may cause spool to bind and/or create high
internal spool leakage.

Install plug/relief valve in inlet section

13. Install the specified option (plug
or relief valve) to the inlet section.
Torque to 27-39 N•m [20-25 lbf•ft]

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Assembly

CENTERING TYPES Assemble the spring/detent assemblies to the valve as specified in the order form. The
stem(s) for each assembly must have Liquid Lock ThreadsTM or equivalent applied. For
CDS 60 tighten the stem(s) to a torque of 2.7-4.0 N•m [2-3 lbf•ft] using a 11mm socket.
For CDS 100 tighten the stem(s) to a torque of 4.0-5.4 N•m [3-4 lbf•ft] using a 13mm
socket.
For loose sections,
complete assembly with
section clamped in a Spring centered assembly (A)
protective jawed vice 1. Install the stem and spring assembly Spring/detent assemblies
before adding to stack.. on the spool using Liquid Lock
ThreadsTM or equivalent. For CDS
60 tighten the stem(s) to a torque
of 2.7-4.0 N•m [2-3 lbf•ft] using a
11mm socket. For CDS 100 tighten
the stem(s) to a torque of 4.0-5.4 N•m
[3-4 lbf•ft] using a 13mm socket.

2. Lubricate the spring assembly with Lubricate spring assembly

Lubriplate 730-1TM or equivalent.

3. Install the end cap over the spring Install endcap over spring assembly
package. Apply Liquid Lock ThreadsTM
or equivalent and install the two
(2) screws and washers using the
appropriate screw driver.

Screw torque:
• CDS 60 and CDS 100 2.7-4.0 N•m [2-3
lbf•ft].

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Assembly

CENTERING TYPES Three position detent assembly (B) Install detent assembly
(continued) 1. Install stem on spool using using
Liquid Lock ThreadsTM or equivalent.
For CDS 60 tighten the stem(s) to
a torque of 2.7-4.0 N•m [2-3 lbf•ft]
using a 11mm socket. For CDS 100
tighten the stem(s) to a torque of
4.0-5.4 N•m [3-4 lbf•ft] using a 13mm
socket.

2. Fasten cap to spool with two screws

and washers. Using a 5/32 hex driver,
torque screws to 5.5-8.2 N•m [4-6
lbf•ft].

Install spring in detent assembly

3 Lubricate the steel balls and
spring with LUBRIPLATE 730-1TM or
equivalent.

4. Install one ball and the spring into

the holes of the end cap.

5. Install second ball on other end of

spring.

Install cover in detent assembly

6 Compress the balls against the

spring evenly and slip the sleeve
over the end.

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Assembly

CENTERING TYPES 7. Install the end cap. Install cover over detent assembly
(continued)
8. Apply Liquid Lock ThreadsTM or
equivalent and install screws and
washers. Tighten to a torque of
2.7-4.1 N•m [2-3 lbf•ft] using the
appropriate screw driver.

Spring/detent detent assembies (C,D&E) Spring/detent assemblies

1. Install the stem and spring assembly

on the spool using Liquid Lock
ThreadsTM or equivalent. For CDS 60
tighten the stem(s) to a torque of
2.7-4.0 N•m [2-3 lbf•ft] using a 11mm
socket. For CDS 100 tighten the
stem(s) to a torque of 4.0-5.4 N•m
[3-4 lbf•ft] using a 13mm socket.

2. Install detent spring and larger steel Spring and ball

ball.

3. Lubricate the crossholes with

LUBRIPLATE 730-1TM or equivalent.

4. Install smaller steel bals in crossholes.

5. Press in larger steel ball using a

punch or allen wrench.

 Do not press the steel ball in too far

or the smaller steel balls may fall inside
stem.

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Assembly

CENTERING TYPES 5. Install detent sleeve. Install detent

(continued)
6. Slide the end cap spacer over the
detent.

7. Slide endcap spacer over spool. Cover extension

3. Install backup washer. ?

Install endcap
8. Install endcap using two screws and
washers.

9. Apply Liquid Lock ThreadsTM or

equivalent.

10. Torque screws to 2.7-4.1 N•m [2-3

lbf•ft] using the appropriate screw
driver.

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Assembly

CENTERING TYPES Spring center/float detent assembly (J) Install spring assembly and spool end
(continued)
1. Install spring assembly and spool
end. Use LocktiteTM on spool end.
For CDS 60 tighten the stem(s) to
a torque of 2.7-4.0 N•m [2-3 lbf•ft]
using a 11mm socket. For CDS 100
tighten the stem(s) to a torque of
4.0-5.4 N•m [3-4 lbf•ft] using a 13mm
socket.

2. Install detent spring and larger steel Spring and ball

ball.

3. Lubricate the crossholes with

LUBRIPLATE 730-1TM or equivalent.

4. Install smaller steel bals in crossholes.

Spacer
5. Press in larger steel ball using a
punch or allen wrench.

 Do not press the steel ball in too far

or the smaller steel balls may fall inside
stem.

6. Slide end cap spacer over spool. Slide

detent sleeve over spool.

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Assembly

CENTERING TYPES 4. Install the two (2) screws and Torque screws
(continued) washers. Apply Liquid Lock ThreadsTM
or equivalent and torque screws
to 2.7-4.1 N•m [2-3 lbf•ft] using the
appropriate screw driver.

5. Screw cap on endcap. Screw on endcap

Hydraulic kickout (F)

Sauer-Danfoss recommends purchasing a complete assembly..

Spring center assembly (G, H, I)

Install spring assembly (G, H, I) using process similar to (A), page 9.

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Assembly

AUXILIARY VALVES 1. Assemble the main relief valve into Auxiliary valve
the inlet. Ensure that the O-rings are
lubricated. The torque for the relief
valve assembly is 41-48 N•m [20-25
lbf•ft], using a 1 inch wrench. For
inlet section without the relief valve
option, go to next step.

2. Assemble the port relief valve(s)

(with and with out anti-cavitation)
into the valve stack section(s). Ensure
that the O-rings are lubricated.
The torque for the port relief valve
assembly is 41-48 N•m [20-25 lbf•ft],
using a 1 inch wrench. Flow control piston option

3. Assemble the plug for the port relief

into the valve stack section(s). Ensure
that the O-rings are lubricated. The
torque for the assembly is 20-27
N•m [15-20 lbf•ft], using a 1 inch hex
driver.

4. Assemble pilot operated check

valves and flow control valves using
the same process used for reliefs.

For sections used without auxiliary Pilot operated check piston option
valves, check to ensure the correctness of
body for function desired.

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Assembly

LOAD CHECK Assemble the load check sections as specified in the order form.

Assemble the load check valves into the valve stack section(s). Ensure that the O-rings
are lubricated. Install the check with spring into the valve section, then install the plug.
The torque for the plug is 20-27 N•m [15-20 lbf•ft], using a 22 mm wrench (CDS 60), 32
mm wrench (CDS 100).

For assemblies with motor spools in the section, the cavity for a load check will receive a
plug. Ensure that the O-rings are lubricated. The torque for the plug is 20-27 N•m [15-20
lbf•ft], using a 22 mm wrench (CDS 60), 32 mm wrench (CDS 100).

Stamp the part number, date code, relief valve setting, build center number on the name
plate in the proper locations. Attach the name plate to the inlet section using two (2)
drive screws.

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Assembly

HANDLE ASSEMBLY 1. Install upper and lower pivot Install pivot assemblies
assemblies using LocktiteTM. Ensure
pivot assemblies are installed equal
distance (use a straight edge) . The
torque for the relief valve assembly
is 40-48 N•m [30-35 lbf•ft], using a 1
inch wrench.

2. Assemble handle linkage using pins Assemble handle linkage

and cotter pins supplied.

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Assembly

JOYSTICK ASSEMBLY 1. Assemble joystick pivot. Use Joystick pivot

LocktiteTM. The torque for the pivot is
40-48 N•m [30-35 lbf•ft], using a 7/16
in wrench.

2. Assemble joystick pivot assembly. Joystick assembly

Use LocktiteTM. The torque for the
nuts is 40-48 N•m [30-35 lbf•ft], using
a 7/16 inch wrench.

Joystick assembly attached to sections

3. Bolt joystick assembly to sections
using hardware supplied.

4. Attach joystick handle. Attach joystick handle

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Assembly

ALTERNATE JOYSTICK 1. Assemble joystick pivot using Joystick pivot

ASSEMBLY LocktiteTM. Use a straight edge to
ensure pivots are equal distance. The
torque for the pivot is 40-48 N•m [30-
35 lbf•ft], using a 7/16 inch wrench.

2. Add a bushing when installing the Add bushing

bearing. Install washer and nut.
Torque nut to 40-48 N•m [30-35
lbf•ft].

3. Install third bearing using long bolt. Install third bearing

Install washer and nut. Torque nut to
40-48 N•m [30-35 lbf•ft].

4. Attach pivot plate using washers and Connect pivot plate

nuts provided. Torque nuts to 40-48
N•m [30-35 lbf•ft].

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Assembly

CABLE ASSEMBLY 1. Install cable connector. Use Install pivot assemblies

LocktiteTM. The torque for the cable
connector is 40-48 N•m [30-35 lbf•ft],
using a 1 inch wrench.

2. Install locknut on cable. Install locknut

3. Install cable end. Cable end

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Assembly

CABLE ASSEMBLY 1. Connect cable to section using pin Connect cable end
(continued) provided.

2. Tighten locknut. Torque to 40-48 N•m Tighten locknut

[30-35 lbf•ft].

3. Slide can over cable end. Slide can

4. Attach bracket to section using Attach bracket to section

screws and washers. Torque screws
to 40-48 N•m [30-35 lbf•ft].

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Testing

OIL AND TEST Connect the valve to a test stand consisting of a hydraulic pump, appropriate hoses and
CONDITIONS fittings, appropriate gauges, temperature control, power supply, and an adequate filter
and tank. The minimum specifications for the test stand are listed below.

• Pressure required: Up to 207 bar [3000 psi] on a regulated line

• Flow required: Minimum of 80 liters/min [10-15 USgal/min] or stack flow and pressure
requirements
• Oil type: Mobil DTE 24 or equvilant
• Oil temperature: 43°C +/- 3°C [110°F +/- 5°F]
• Oil cleanliness level: ISO 19/16 (10 micron or better; suction and return)
• 12/24 Volt DC power supply and digital volt meter
• Remote joystick

ADJUSTING PRESSURE Main relief valve

SETTINGS Test the main inlet pressure relief valve by applying oil pressure on the pressure port of
the inlet section.

1. Install a 69 bar [1000 psi] gauge in the pressure port of the inlet section.

2. Connect the tank port to the tank.

3. Shift one of the spools in a section to block free flow through the valve.

4. Set the main Inlet relief of the valve assembly to customer required specification.
Refer to Sauer-Danfoss publication CDS stack valve assembly order form 520Lxxx for
relief settings.

Work port relief valve

Test the work port pressure relief valves by applying oil pressure on the work port.

1. Install a 69 bar [1000 psi] gauge in the work port of the selected section.

2. Connect the tank port to the tank.

3. Block all other ports off with steel plugs.

4. Set the port relief of the valve assembly according to Sauer-Danfoss publication CDS
stack valve assembly order form 520Lxxx.

Adjusting main/port relief valves

Adjust the main/port relief valves by loosening the lock nut (17 mm) and turning the
adjusting screw (11 mm). Turning the adjusitng screw clockwise raises the relief pressure
and turning counterclockwise lowers the relief pressure. Retest the relief pressure.
Continue to turn the adjusting screw, lock the locknut, and retest until the desired setting
is reached.

Non-Adjustable relief’s are adjusted by adding shim or shims of various thickness until
the desired setting is obtained.

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Testing

LEAKAGE TESTING Work port leakage

Plug all ports except work port to be tested and tank port. Apply 69 bar [1000 psi] to
the work port of each section. Shift spool slightly to prime the passage way before
starting the test. Check for leakage out by using goose neck style tubing (shown below)
in the outlet port. With the spool in the neutral position,pressurize the work port and
check leakage rate for 10 seconds. Check a minimum of twice per port. Rotate spool 180
degrees befor to checking the second time. Maximum leakage allowed out the outlet
port is 16 cc [1 cubic inch] per minute (2.6 cc [0.16 cubic inch] for 10 seconds).

Load check leakage Leakage testing apparatus

See note on oil and test conditions page

22.

Apply 69 bar [1000 psi] to the work port

opposite handle assembly. Plug all ports
except work port and Pressure port. Shift
spool slightly to prime the passage way
before starting leakage test.
Shift the spool in the full out position
(towards operator) to check for leakage.
Maximum leakage allowed out the outlet
port is 80 cc [5 cubic inches] per minute
(22 cc [1.4 cubic inches] in 10 seconds). Leakage testing

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Testing

FUNCTION TESTING Function testing insures the correct dynamic manual operation of the CDS stack valve
assembly. Perform this test after completing the pressure adjustments. Test each section
of the assembly. Connect each section to a hydraulic cylinder to perform the test. Install a
gauge (69 bar [1000 psi]) in the cylinder extension and retraction lines.

1. Connect the valve to pressure and tank. Plug all work ports except the ports from the
section to be tested.

2. Connect the A port of the valve to the rod end of the cylinder and the B port to the
base end of the cylinder.

3. Shift the control lever of the section in (towards the valve) and observe cylinder
retraction. Shift the same control lever out (away from the valve) and observe
cylinder extension. Repeat several times.

On valve groups with lever(s) on the B side, the cylinder movement will be opposite.

4. Check the spool travel smoothness in both directions. Sticky spools indicate
problems with the O-rings. Replace the section if spool travel is not smooth.

5. Check the metering of the spool in both directions. The speed of cylinder extension/
retraction is controllable by metering the spool.

6. Check each work port for the ability to build full system pressure, as limited by the
port relief if present. Hold the lever at full stroke after the cylinder reaches the end of
the stroke. Line pressure should not go above relief setting.

Spring Center Function

1. Shift the spool manually in one direction and let go of the control lever. The valve
should center itself, with no hesitation. If the control lever sticks in any position,
check for binding of the spool.

2. Check spool return in both directions. If the spool sticks, replace the section.

Detent Functions
1. Shift the spool in one direction manually. Let go of the control lever. The spool
should remain in shifted position.

2. Check detent function in both directions. If the control lever moves back in neutral
position, check for cause of the spool movement. Repair or replace detent function.

24 520L0924 • October 2005

 CDS Directional Control Valve Assembly and Testing Manual

Testing

FUNCTION TESTING Float Functions

(continued) Spools with the detent float option have four postions. Spring center for three positions
and detent for the fourth. The fourth position (float) may be detented in the extreme in
or out position of the spool travel.

The difference between the spring center function and this fourth postion (float) ,is that
the work port and inlet flow dumps to tank once shifted into detent.

1. Shift the spool to detent position.The spool must remain in detent when the handle
is released.

2. If the control lever goes back to neutral after being moved to detent, check for the
cause of the spool movement. Rebuild or replace the detent function.

Pneumatic Function
1. Apply air pressure to actuator. The spool will shift with 4-12 bar [58-174 psi] air
pressure applied for each direction. Shifting pressure will vary pending size of valve
(CDS 60/100), valve flow, and pressure requirements.

2. Remove air pressure. The spool should return to neutral. Check function in both
directions. If the spool does not return to neutral, check for cause of spool bind.
Replace actuator. Replace section if necessary.

Hydraulic Function
1. Apply hydraulic pressure to actuator. The spool will shift with at 35-100 bar [116-
1450 psi] pilot pressure applied for each direction. Shifting pressure will vary
pending size of valve (CDS 60/100) and valve flow and pressure requirements.

2. Remove pilot pressure. The spool should return to neutral. Check function in both
directions. If the spool does not return to neutral, check for cause of spool bind.
Replace actuator. Replace section if necessary.

520L0924 • October 2005 25

 CDS Directional Control Valve Assembly and Testing Manual

Testing

FUNCTION TESTING Solenoid Function

(continued) Testing electrical sections requires a power supply (12-24 volt) and appropriate electrical
connections. Install a gauge (69 bar [1000 psi]) in the working port of the spool being
tested.

Before testing, be sure a pressure build up valve has been specified in the outlet section.
Pressure to shift the spool will depend on the number of sections and a given flow to
create required standby pressure for each section. 6-8 Bar PSI needed to shift CDS 60 and
? for 100

1. Apply voltage to one solenoid. The spool should shift to its working position with the
appropriate pressure being generated in the working port. Disconnect the voltage.
The spool should shift to its neutral position.

2. Apply voltage to the second solenoid. The spool should shift to its working position
with the appropriate pressure being generated in the working port. Disconnect the
voltage. The spool should shift to its neutral position.

3. If the spool does not return to neutral, check for cause of spool bind. If the spool has
not returned to neutral, the inlet pressure will remain at a higher than standby level.

If numerous valves will be tested, it is recommended to build a working coil into the
test stand (for example:12 volt coil with flying lead). This ciol can be used to check the
function of the valves. After proper valve function has been determined, a production
coil can be installed on the valve.

Three Way Spools

For valve groups with 3-way spools, the test procedure will be the same as a single port
from a 4-way spool.

After all sections have been tested, verify that all relief valve settings are still correct.
Refer to Adjusting pressure settings section page 22.

BACKPRESSURE TEST 1. Plug all ports except the outlet port with steel plugs.

2. Apply 39 bar [570 psi] pressure to the outlet port.

3. Inspect all areas for external leakage. Any leakage is unacceptable. Replace the O-
rings between any sections that leak.

4. Remove all steel plugs, fittings and hoses. Drain the oil from the valve. Install plastic
plugs in all ports.

26 520L0924 • October 2005

CDS Directional Control Valve Assembly and Testing Manual

Notes

520L0924 • October 2005 27

 CDS Directional Control Valve Assembly and Testing Manual

Troubleshooting

THE VALVE LEAKS

Disconnect......

Item Description Action

IT STILL LEAKS

Item Description Action

28 520L0924 • October 2005

 CDS Directional Control Valve Assembly and Testing Manual

Troubleshooting

STICKY SPOOL

Item Description Action

RELIEF DOESN’T WORK

Item Description Action

CABLE BINDS

Item Description Action

520L0924 • October 2005 29

 CDS Stack Valve Assembly and Testing Manual

Appendix

APPENDIX A The following page contains the CDS stack valve test certification form.
TESTING CERTIFICATION
FORM A copy of the certification must be sent to the TST at Sauer-Danfoss, Easley, SC.

Fax number 864-XXX-XXXX.

30 BLN-10263 • 520L0924 • October 2005

 Sauer-Danfoss
CDS Stack Valve Test Certification
SYSTEM #: DATE CODE: BUILD CENTER #: QUANTITY:
INLET: WITH RELIEFS W/O RELIEFS RELIEF SETTING GPM SETTING:

WORK SECTIONS OPTIONS ACTUATORS FUNCTION

SECTION SPOOL Port PILOT PORT LOAD MANUAL HYD. PNEU ELECT OTHER
TYPE Leakage CHECK RELIEFS CHECK
1.
2.
3.
4.
5.
6.
7.
8.

ASSEMBLER: DATE: TESTER: DATE:

NOTES:

S015 01/99
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