Major brake problem

[npca-jesse]

Well gang , I guess I wouldn't be a Patrol owner if I didn't have some kind of brake problem.  I have a brand new brake cylinder on the rear passenger side of my rig that keeps locking up.When we tear it down , it seems that the piston cup is pushed way out of the cylinder. It also happens with the old cylinder so I know its not the cylinder. My evaluation is that somehow I am getting too much pressure to just that one wheel . If anyone out there knows whats happening to my brakes I sure would like to hear from you.

[npca-viking]

I do not believe pressure could be an issue as the length of piston travel within the servo cylinder is dependent on the distance between the shoe surface and the drum. Once that travel is complete - with the shoe hard against the drum, all the pressure in the world can not make that piston travel further - assuming the servo cyclinder is well secured and the drum does not explode.(wry humour) Your description  sounds like you are not adjusting your shoes to proper drum clearance during your repairs. Drum brakes should not rub like disc brakes but you should turn the adjusters until contact is made - turning whilst making the adjustment - and then back the shoes off just a tad. The older members can tell you what tad is best. As these shoes supposedly automatically orientate to centre though don't always comply immediately, it is good practice to set the brakes hard a few times and then re-adjust in case the shoes were sitting a little off centre during your first adjustment run. On the front wheels there are two cam adjusters for each wheel. On the back ones, there is only one adjuster for each wheel. They all work on the cam principle and are easy to get at from under the vehicle. clockwise brings the shoes closer to the drum and the opposite is of course true.  If these adjustments are not correct the pistons have to travel too far to get the shoes to the drum and hence an over extended piston and jaming in the servo.  

[npca-jeepy]

It is also possible that the adjusters are not properly adusted. If the adjuster is not out farenough on the bottom side (?) then the wheel cylinderpushes out too far to compensate. It will wearthe shoes funny as well as push out the piston andyou will lose your brakes completely when that happens due to old style brake line designs. Thatis the most likely problem. Try that and let meknow what happens...jeepcj_6@yahoo.com