Talk:Master cylinder

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The pressure is NOT created in the reservoir, but in the brake lines leading to the wheel cylinders. — Preceding unsigned comment added by 71.108.119.10 (talk) 03:32, 31 July 2007 (UTC)[reply]

Also, there are no primary and secondary cylinders. In a four-wheeled vehicle two in-line pistons operate two independent circuits, each one acting upon two wheels.

In case of failure of a brake line only two wheels will be slowed, usually one front wheel and the rear wheel on the opposite side. — Preceding unsigned comment added by 71.102.117.124 (talk) 05:03, 1 August 2007 (UTC)[reply]

That's incorrect on both points, 71.102.117.124. First, that's only "usually" in a FWD car; all other vehicles usually have 1 circuit to front brakes, the other circuit to rear brakes (FWD cars are just so front-heavy). The other issue you replied about also gives a false generalization:

I also happen to own a "four-wheeled vehicle" with 2 separate cylinders, not "in-line" pistons in one cylinder as you claim (all quotes I used are of you); google for Adjustable Brake Balance Bar to see such a setup, and how the brakes on 2 wheels still will work if the other 2 brakes fail; this allows each cylinder to develop more or less hydraulic pressure than the other circuit, as needed. But my car's case is rare (either high-production vehicles that were modified for racing, street-legalized vehicles with racing heritage, e.g. a GTR from www.ultimasports.co.uk, or racing vehicles that won't ever be street-legal, and as the guy below notes, many older cars). The next guy gets everything else right, too:216.188.254.2 (talk) 05:33, 12 September 2009 (UTC)[reply]

The pressure is NOT created in the brake lines, but in the bore underneath the reservoir. The lines simply contain the pressure until it can expand at the caliper or wheel cylinder. I agree that the original statement is very inaccurate especially the part stating that if a line blows the pressure is automatically re-routed to the intact line. Nope... The pressure will take the path of least resistance. Only the 'other' piston will provide braking power to the wheels that it is connected to. I should mention that the original statement is wrong when it said that all master cylinders have two pistons. Plenty of older cars (usually from the 60's or earlier) had a single piston. —Preceding unsigned comment added by 24.186.139.177 (talk) 03:05, 18 July 2008 (UTC)[reply]

A line break causes loss of brake fluid. If the master cylinder did not redirect the pressure, failure of one line would soon drain the reservoir and result in failure of the entire system. There would have to be separate reservoirs Pendragon39 (talk) 21:47, 12 September 2008 (UTC)[reply]

Well, separate sub-reservoirs are needed, and most cars have them; 24.186.139.177 had it right. Reservoirs will have one twist-on filler cap (thus one "reservoir" needs to be filled: an important point, just so the article doesn't confuse anyone, but it's only a matter of semantics), but a typical reservoir creates separate sub-reservoirs near the bottom, by moulding a "divider" into the reservoir's floor, so that a small "sub-reservoir" for 2 brakes will be maintained even if the other 2 brakes have drained their sub-reservoir (and vice-versa); it looks somewhat like this crude drawing:

           |  MAX FILL |

           |  MIN FILL |  <--- "main" reservoir

            \    |<-- / ---- divider, usually near center. It only goes approx 1/2 

              \__|__/        of the way up to the "MAX FILL" line or reservoir's twist-on cap.

                |  | <--- low-pressure hydraulic tubes. One outlet from the reservoir is on  

        _______/    \__________  each side of that divider; one outlet goes to each master cylinder.

This tube ^^here^^ goes to mstrcyl #1

This other tube, above ^^these^^ carats (a "carat" is shift+6 on your keyboard LOL), goes to master cyl #2

216.188.254.2 (talk) 05:33, 12 September 2009 (UTC)[reply]

"but at least gives some braking ability, which some people prefer instead of having no braking ability."

This is so awkwardly worded. Does it even bear mentioning that some people might enjoy being able to stop if their brakes start to fail? I'd like to think that *all* people would enjoy this. I'm going to change it to sound less awkward and "weasely." I hope someone more proficient at writing than I comes by later and revises it further. --74.192.62.243 (talk) 19:57, 13 October 2009 (UTC)[reply]

As regards the introduction to this article. At the date of viewing it remains flagged. I thought some suggests might help. So please amend, expand and clarify. I would change it myself but to be honest I am actually too concerned that I might upset someone by even adding this thread.

1. Original introduction as found: (but sans links, citation, text formating etc.):
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The master cylinder is a control device that converts non-hydraulic pressure (commonly from a driver's foot) into hydraulic pressure, in order to move other device(s) which are located at the other end of the hydraulic system, such as one or more slave cylinders. As piston(s) move along the bore of the master cylinder, this movement is transferred through the hydraulic fluid, to result in a movement of the slave cylinder(s). The hydraulic pressure created by moving a piston (inside the bore of the master cylinder) toward the slave cylinder(s) compresses the fluid evenly, but by varying the comparative surface-area of the master cylinder and/or each slave cylinder, one will vary the amount of force and displacement applied to each slave cylinder (relative to the amount of force and displacement that was applied to the master cylinder).
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2. Suggested:
__
The master cylinder is a component of `some` hydraulic systems. The primary function/s of the master cylinder is to transfer, regulate and distribute pressure within a/n hydraulic system. External, non-hydraulic pressure/force is converted by the master cylinder into hydraulic pressure. The converted pressure is then conveyed within the hydraulic system to one or more slave cylinders, hence the name `master`. The pressure is created(?) by (?) and (?). As piston(s) move along the bore of the master cylinder, this movement is transferred through an hydraulic fluid, which results in a movement of the slave cylinder(s)......etc
--
Dj.cowan (talk) 01:34, 12 August 2010 (UTC)[reply]

http://en.wikipedia.org/wiki/Felix_the_Cat_(TV_series) has the master cylinder character that I was looking for. — Preceding unsigned comment added by 74.162.158.119 (talk) 23:03, 13 November 2011 (UTC)[reply]