how do u tell if a rear wheel cylinder is in good working condition???

im doind my rear brakes on a 89 jeep cherokee and was planning on replacing the drums and shoes

im wondering how do i tell if my wheel cylinder is in good working condition? is there a way to test it? or a way to know if i should replace it?

Last one I replaced was dripping brake fluid. They are cheap and easy enough that you should replace them if you are concerned about their condition or functioning.

You can open the rubber end cover a little and see if fluid leaks out, usually the first sign they are failing. If your careful to just partially open the cover in the front (facing you), it is a lot easier to get back on.
Taking the brake line off of the wheel cylinder can be iffy, not something I'd want to do if I could avoid it.

8Mud said:

You can open the rubber end cover a little and see if fluid leaks out, usually the first sign they are failing. If your careful to just partially open the cover in the front (facing you), it is a lot easier to get back on.
Taking the brake line off of the wheel cylinder can be iffy, not something I'd want to do if I could avoid it.

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X2. That is the best way to tell if they are leaking. My experiances though was opposite. The pistons on mine froze as in they do not leak and they do not move. While you are there, check that also by pushing on the metal part of the piston that touches the shoe/s with a screw driver. It should move a little.

Tim_MN said:

Last one I replaced was dripping brake fluid. They are cheap and easy enough that you should replace them if you are concerned about their condition or functioning.

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when in doubt change em out

I knew mine were bad ebcause the boots fell off and it was rusty inside LOL... but like they said. They are cheap so just replace them if there is any doubt.

as stated above, check to see if they are leaking. you will see signs of an oily mess in there with more grime than normal. you may also see some swelling of the shoes friction material if they were soaked in brake fluid. it is only one flare nut and two bolts that hold it on so its not that hard to replace. i replaced mine when i did my drum brakes initially on my xj and also on my dodge ram. its cheap insurance to replace the wheel cylinder. its also a great time to flush out the old brake fluid with fresh stuff. if your brake fluid is dark instead of the color of freshly opened brake fluid, then it needs to be changed. the easiest way is to just bleed the pass rear (furthest from the res) until only clear fluid comes out, being sure to check and fill the mc often.

be sure to put some anti-sieze on the threads of the self adjuster. infact unscrew it all the way and clean the threads, then put the anti-sieze on. or you could try a good high temp grease, but i prefer the first option. it wouldnt hurt to put on all new hardware as well. vatozone and chucker both sell the hardware kit and is cheap insurance on the springs and such.

i find that drum brakes are a total PITA. thats why i went to rear disks.