6 replies to this topic

[087dave]

Hi all is there any test to do, to prove that a brake pressure limiter(mounted on rear subframe) is working

Thanks

[KernowCooper]

What problems do you have ? are the wheels locking or not given any braking force? not seen any means of testing it but a run on brake rollers would indicate what brake force is taking place on the rear.

If the valve was not limiting the pressure the rears would lock up under heavy braking, if you jack up the wheel can you feel the brakes come on ?

If your in any doubt it may be faulty I'd change it.

Edited by KernowCooper, 13 January 2013 - 10:08 PM.

[087dave]

i am currently having problems bleeding my brakes i have gotten rid of all the air out of the brakes plus the master cylinder
and am trying to rule the limiting valve and just want to know how to test it

when i pump the pedal i get a hard pedal leave it a while and it goes soft.....so is there any test for it
Thanks

[bmcecosse]

It's not the limit valve if you are getting fluid from the rear bleeders... Are the rear drums adjusted up TIGHT with the handbrake OFF?.

[087dave]

Ya all is tightened with the hand brake off

[KernowCooper]

Sounds as though you still have air in the system, I take it as you have a pressure limiting valve on the rear subframe its a single line system. If once you find the pedal is soft can you pump air out of the system again? if you have no leaks with the system under pressure then I'd be looking at the master cylender.

[tiger99]

The symptoms are clearly those of one of more faulty cylinders, most likely the master cylinder. However, be aware that the lip seal in any cylinder may seal under pressure and leak when there is no pressure if the cylinder bore is less than absolutely perfect, which can also cause the same symptom of letting air in when pressure is released, while leaking hardly any visible fluid, for a while at least.

I have very rarely been able to re-use old wheel cylinders on any car, as almost always the bore is worn beyond acceptable limits, scored or corroded, and new seals will not work in these circumstances. Cylinder bores really must be PERFECT.