Cant stop braking..

[Fozzy]

Well I have exhausted my knowledge on braking systems trying to sort this issue so it is time for me to ask for some help.

First of all the car is a 1991 holden rodeo.. When I first got it this problem was not an issue. It has only come about after about 2 months of sitting while I farted around painting it etc..

What appears to be happening is when the brake fluid starts to get hot the front brakes are "locking on" (by locking on they dont seem to be returning off the rotor not just fully jamming on) I am convinced it is not the wheel bearings as there is no noise and the feel of the pedal changes significantly just prior to the brakes staying on.

I pulled them down yesterday and the caliper appears to be operating normally as in the piston moves in out out without to much fuss. I fully drained and bled the full system.. This appeared to fix the issue however it has started to happen again..

It is possible that because the pads are quite low the piston is reaching the end of its travel... However I think that it would be very unluckly if that was the case.

I am just about convinced it is more than likely the master cylinder sucking in air or has a fucked seal internally. As I can see abit of paint damage from where brake fluid has leaked out between the master cylinder and the booster..

Anyone who knows brakes have any ideas??

Thanks
Scott

[TJ]

isnt there a return valve which pushes the fluid out of the pistons?

if that fails, it will hold the brakes on as there will be fluid, and pressure pushing the calipers.

[luke20t]

but when this happens the brake pedal will get harder and harder every time u push it. eventually the pedal will be rock solid and the brakes will stay on and u wont be able to drive.