Brake seizure

Post by **my_modern_car** » Sun Apr 26, 2009 8:51 pm

My Mog has been sat for a while whilst I changed the engine. That is all done, and I come to a serious road test only for the brakes to lock on. Upon examination the rear cylinders are sticking on.

Now, all cylinders were replaced last November for the MOT. So, what can be done to stop them sticking? I have heard the suggestion of 5-dot fluid (silicone based, so not hygroscopic). Is there any evidence that this would help?

Any comments would be greatly received.

Post by **aupickup** » Sun Apr 26, 2009 8:55 pm

also leaving the handbrake off helps the rears

Post by **bmcecosse** » Sun Apr 26, 2009 10:44 pm

It's likely to be the outer (non hydraulic) pistons that have seized - or possibly even the cables! Just strip the brakes down and free off the cylinders and/or cables. Apply a little 'red' grease to stop it happening again. As Dennis says - never leave the handbrake on if the vehicle is sitting for any time.

Post by **rayofleamington** » Sun Apr 26, 2009 10:59 pm

same as above - if it's the outer pistons that are stuck then it's not too hard to fix.
One really useful component is the rubber boot that goes over the cylinder and handbrake arm. Some are hard PVC and hardly worth using but if you get a decent version of the boot it will keep much of the moisture from entering the slot in the back of the cylinder (otherwise it's completely unprotected from road splash)

Post by **my_modern_car** » Mon Apr 27, 2009 1:34 pm

Alas I have taken the non-hydraulic part off and it's fine. Take the point about leaving the handbrake on though.<br><br>

<br>

Post by **mike.perry** » Mon Apr 27, 2009 2:24 pm

Can you push the inner piston in gently with your finger?
Whilst you have the wheels off give the handbrake cables a good service.
Release the handbrake fully and disconnect the cable from the wheel cylinder.
Pull the inner cable through as far as possible and check for fraying where it comes out of the outer cable.
If OK then grease the cable if it has a grease nipple
Oil the end of the inner cable and work it backwards and forwards into the outer cable.
Reassemble
When the front and rear brakes have been adjusted then jack up the car under the diff and support both sides of the axle on stands with both wheels replaced
Adjust the handbrake cables so that both wheels are fully locked after 5 clicks.
Release the handbrake 1 or 2 clicks and there should be an equal amount of resistance on each wheel, adjust if necessary

Post by **bmcecosse** » Mon Apr 27, 2009 10:53 pm

Probably just need a bit of use to free off the inner pistons - my car gets like this after it's winter lay-over, but a few miles up the back roads soon has them free and easy again!