shirley

Hello
i have a 2.5 petrol jeep cherokee, registered 1/1/1996. when driving a few miles or when car reaches running temperature the front brakes gradually lock on until mthe car cannot move. was told initially needed new servo/master cylinder. due to age of vehicle no jeep parts readily avialable so mechanic suggested seocnd had parts which i sourced from a reputable jeep breakers. parts arrived & looked identical to existing ones although the bendix part numbers were different. Breakers insistent parts are suitable for my vehicle, however despite fitting new parts problem same and front brakes seize up after a couple of miles.
Mechanic then tried new hoses, this didn't work, brakes have been bled a few times I am told and calipers are working freely. Could it be the new servo/master cylinder are incompaitable, some comment about perhaps diff pressures? seems an awful co-incidence for both new & replacement parts to have same fault.
Can anyone help with this problem as otherwise a perfectly good vehicle that has only done 50, 000 miles may remain unusable
hope someone out there can help as my mechanic now hasnt an idea of how to resolve
thanks

Turbo X_J

1. Adjust the pushrod to insure you have freeplay between the brake pedal and the master cylinder.


You can also check for:
1. Brake line running to close to the exhaust system
2. Collapsed flexible hose going to the caliper

shirley

Many thanks, will get my mechanic to check pushrod and also check brake lines not too close to exhaust system. he has however replaced flexible hose, but this did not cure problem. is it likely to be a servo/master cylinder fault? and if so is it likely both existing and replacement parts were both faulty? Are jeep servo/master cyclinders specific to each year/model, i.e. would a 1996 version differ to an earlier/later part?