jshultz78

94 sport, no abs.

New master cylinder, new wheel cylinders/rear shoes, had drums turned. Had newish pads on front when I got it, even before all the mentioned parts, the brakes has been crap. Booster is fine, I can pump brakes up with car off, then start it and the pedal will fall down about half way, check valve is fine, I can only blow one way thru it. New brake fluid through all the lines, prob used 3 bottles of fluid to bleed them to make sure all the old stuff was out. All 4 corners pump up and bleed the way they're supposed to.

The brakes are fine for just cruising around town, it stops good on pavement, I really don't think I could even lock them up if I had to. Backing off the 4post lift at work the other day I had to stand on the pedal before it would stop on the incline. Is there something I'm missing? I really want to go ride some trails, but not with the brakes like this. I've read about doing the 95-96 booster, but I can't find any in the local junkyards.

I may try new rotors and pads up front, may make it better, hell I drove my 93 blazer today and about wrecked it because the brakes are 1000 times better on it. Wish there was a way to do an s10 booster on the xj.

cruiser54

Did you manually adjust the rear brakes?

99 to 2004 wJ booster/master works well.

jshultz78

Haven't went through the adjustment hole yet, but adjusted them out to where the drum would barely slide over the shoes, I'll go back and put a little more drag on them and see what happens.

Nick-B

We don't know anything about your rig. Are you running big tires? If so the stock brakes won't handle the extra leverage. Upgrades like the WJ booster/MC as Cruiser suggests will be needed.

jshultz78

94 sport 4x4. 235-75-15 tires on Comanche stock wheels

jshultz78

I got new pads and rotors to go on today. The rotors look like they're glazed a little

diskman

Yup. Make sure the rears are adjusted fairly snug. The fronts don't start clamping until the rears do.

I got my '92 to stop on a dime with the Grand Cherokee booster and MC replacement too.

cruiser54

Ever check this dimension?

Tbone289

A couple of months ago I realized the self-adjusters on my rears had been stuck for several months, so I did a drum clean-up, lube and re-adjust. The improvement in stopping power and pedal feel was an eye-opener. Last week I installed new Centric premium rotors and semi-metallic pads, and now the brakes are amazing.

I'd advise you to bed the new pads and rotors in properly as soon as you install them. Don't just drive around normally for weeks waiting for them to bed-in on their own.

This is basically the procedure I follow: http://brakeperformance.com/bedding-in-rotors.php

cruiser54

Absolutely bed them in!!!

jshultz78

I had cleaned the self adjusters when I did the rears. Went ahead today and picked up a complete rear hardware kit. It's prob a combination of that and I didn't have the rears adjusted far enough. I set them like I do my s10s. This is the first non gm truck I've ever had. Lol

TrailerTrash

Have you checked the spots that the brake pads slide on? They can wear deep stopping the pads from clamping properly

Suprmn

I do not have time to look up a link, but I have most recently learned about the plunger in the proportioning valve. It can get off center during brake bleeding and not reset causing issues similar to what you are talking about. They make a tool to keep is centered during bleeding. Just ordered one up myself.

4.3L XJ

One issue no one has brought up is the material the pads and shoes are made of. Lifetime linings are very hard and need to be warmed up to stop. They are however fade resistant. The cheap ones will stop you quickly at lower speeds and tend to fade a little at high speed panic stops and make lots of dust on the wheels. I finally got rid of my lifetime front pads because they just didn't stop well

jshultz78

Update.

got the pads/rotors and rear hardware installed, pedal felt alot better, half-assed bedded the pads, got home in the dirt, the passenger side would lock up in the dirt but the driver would barely slide, backed up and drove foward and hit the brakes a few times, then went back down to the main highway, about a mile, noticed it was kinda bogging down, not driving right. Got it back home and the front brakes were dragging. Smoke pouring off the fronts. Rears were barely warm. Tore it back down, went ahead and welded up the tiny grooves where the pads ride on the knuckle. About to go drive it again and see what happens. The only thing I can think of is after I pushed the caliper back in It could have overfilled the master cylinder causing it to pressure up?