Brake Problems

1992 Cherokee Laredo that had ABS.

The jeep has newer rotors, calipers, pads up front...new drums, cylinders, pads and hardware in the rear. Rears were adjusted for correct drag. This was all done in the spring.

So for awhile now I was experiencing an issue with the brake peddle sticking a little....I'd have to pull up with my foot to get it to come up to release the drag and brake lights. Other than that everything worked fine. This occured sometime after the brake work was completed...pretty much early summer if I recall correctly.

I had been wanting to ditch the ABS system and thinking I would like to change the booster and master cylinder anyway I decided to rip all the ABS crap out and replaced the master cylinder and booster with a unit out of a 2001 Grand Cherokee based on some write ups I read.

Got everything hooked up, reflared the brake lines into the proportioning valve last week and bled the brakes today and took it for a ride. At first it felt fine, except I noticed my steering wheel was cocked a little...Hmm thats strange....well...that should have been the first sign something was amiss.

As I drove it I noticed the brake peddle was getting firmer and firmer to the point it was rock hard and the engine was struggling to move the jeep.

I finally gave the underside of the peddle a good pull with my foot and while I didn't feel any movement up..the brakes released immediately. The peddle feel was back to normal the last couple miles back home with one issue. If I stopped too hard the right rear brake would lock up.

Pulled in the driveway and both front rotors were close to 400 degrees and the passenger rear drum was 180 while the driver rear was only around 100.

So all you Jeep gurus....I need a little hand holding now. I am not sure whats wrong.

Sounds like your check valve for the abs is stuck.

Abs is gone. Its all been ripped out.

That's cool but there's a check valve for abs. I'm not sure where it's located on your jeep.

The only reference to a check valve I can find is the one in the brake booster. If there is another one somewhere can some one tell me where to locate it?

Maybe something wrong w/ the master cylinder.

I think, PLEASE don't hold me to this, it's in the proportioning valve. Some are, I've found on other vehicles, in the master cylinder. Either way, you're brakes dragging, pedal not coming up, are leading me to this conclusion. But, I could be way off.

I'm in Red Lion PA. 17356. How far away from me are you? PM me and I'll give you my number. If you're reasonably close I'll swing by and give you any help I can.

If the "brake" light is not on, that would pretty much rule out the prop. valve.
Temps., sound right because the m/c is biased to the front.
Good possibility the spool in the master is stuck.

That's it! Damn, I couldn't for the life of me remember what it was called. Thanks for clearing that up. I apologise for the misidentification.

Update. Took the Master and Booster out. Measured the pushrod length vs the old. The old is 4 7/8 inches from the mounting surface to the center of the pushrod hole...the new is 5 1/8 inches. DOH...how did I miss that.

Added 1/4 inch spacer and reinstalled.

Changed all the softlines out as well.

Started bleeding the passenger rear and blew the drivers rear hardline. WTH.

So I wrapped it up for the day. Have to get some new brake line and am just going to redo both hard lines in the rear at the same time. This Jeep is fighting me every step of the way.

Yeah, your on the right track.
If those are the original rear lines its time to twist up some new ones.
I must have lucked out, my 2000xj limited does not have abs. The original owner optioned it out? don't know.