rear brakes....

I had my 1995 Cherokee on a lift and was going from park to reverse and I let the rear wheels spin up and tried to stop them and I had to slam the pedal to the floor just to get them to slowly come to a stop. I then adjusted the drums using a screwdriver until it was difficult to turn the wheels by hand. This didn't help a bit. I then pulled the drum off to take a look and found everything in great condition as I replace d every component (shoes, adjusters, springs, wheel cylinders.....) about 10 months ago. Next I checked for any ballooning of the flex line. I then checked for hydraulic pressure simply by opening the valve at the drum and having someone depress the pedal and watching the fluid shoot out rapidly. Any advice as to my next move?

Thanks,

Jeff

ABS??

I think your master cylinder is shot. Or water or air in the line.

stock tire??

The rear brakes on the XJ are a sad excuse for a breaking system. With both wheels off the ground the engine idling withthe transmission on 'D' it is all but impossible to stop the rear weels from turning; that is with out standing on the break pedal. Rear disks and a higher volume master cylinder is the only solution in my opinion.

non-abs and basically stock tires.....

Does the brake trouble light come on? The trouble light will come on when there is uneven braking front and rear (also at start up to test the bulb). Often an indication of a bad master cylinder, serious air in the system, brake line leak,or a leaky wheel cylinder, when it lights while applying the brakes.
Does the brake pedal get higher when you pump it?
A leak. air or bad master cylinder, will most likely light the brake light.
Have read of more than a few people having trouble with a partially plugged proportioning valve.

8Mud said:

Does the brake trouble light come on? The trouble light will come on when there is uneven braking front and rear (also at start up to test the bulb). Often an indication of a bad master cylinder, serious air in the system, brake line leak,or a leaky wheel cylinder, when it lights while applying the brakes.
Does the brake pedal get higher when you pump it?
A leak. air or bad master cylinder, will most likely light the brake light.
Have read of more than a few people having trouble with a partially plugged proportioning valve.

Click to expand...

A plugged propotioning valve I do not know about. There is no light or any indication that there is any thing wrong with the breaking system. Pumping the breaks wpuld raise the pedal a bit but does nothing for breaking improvement.

I know two people who have traced this problem to the combination/proportioning valve. I am about to try what the FSM says cannot be done, and reinstall a reconditioned (by me) XJ combo valve into an MJ to see if the FSM is correct, or if cleaning and de-gunking can make it work again.

The first guy I know who zeroed in on this dumped the factory combo valve and went with a new Wilwood manually adjustable proportioning valve serving only the rear circuit. Good solution if you don't ever plan to sell the vehicle, but doing it that way loses the brake system warning light and it may not be legal to sell a vehicle in which that doesn't work.