This is something I've been dealing with for a few years now. A few years ago my front driver side caliper was stuck. I had the rotors, pads and calipers replaced. About a year later, the passenger side locked up. Got that caliper replaced as well and the bracket as the mechanic said it wasn't any good. I also had the the pads and passenger side rotor replaced. I didn't change the rotor on the driver side yet because they were sold out. Should be in any day now. So the problem I'm still having happens after driving on the highway for a little while. And it doesn't always happen. When braking, I'll notice the pedal get a little spongy and the car begins to shake. If I release the brake it goes away. Today I drove on the highway for several miles and it didn't happen. But it will happen again. Most likely after it's been driven at high speeds (60+) for a little while. Several mechanics looked at it, drove it and said it was ok. Can anyone shed any light?

 

Maybe some info, such as year and model would be helpful. Replace the rotors, pads, and hoses. Do a proper break in procedure and make sure the rear brakes are working.

 

Thanks for the prompt reply. It's a 2002 jeep cherokee laredo. 4.0. I also forgot to mention the front hoses were replaced as well as the lines leading to the back.

 

Check the caliper slides and make sure they are not grooved, the groove will hang the pads up and cause problems.

 

Are those the same as the pistons inside the caliper? I'm not a mechanic so I'm not that familiar some terms.

 

No, it's the part of the steering knuckle that supports the brake pads.

 

I've found out from experience you can't nickle and dime these braking systems. You've gotta go all out with the brake jobs. New calipers, rotors, pads and hardware if you want trouble free efficient braking. Check out what Busted mentioned it is a common spot for the pad to hang up also, if the pins on the calipers aren't properly lubed, that can also cause the caliper to hang up. Can't say for sure but it sounds like you're building up excessive heat somewhere and that is causing the spongy pedal. It could be that you now have a scorched or warped rotor causing the shake which was caused by one or more of the above mentioned possible issues.

 

http://m.autozone.com/autozone-mobile/en/parts/Cardone-Reman-Brake-Caliper-Bracket-Front/_/N-jhkelZ8knuq?id=217459.

An automotive said this is what you might be referring to.

 

Okay guys. The WJs have separate mounting brackets for the calipers because of this grooving problem. They are not part of the steering knuckle anymore like they were on the ZJs.

His problem is probably because he piece-mealed it, doing something to one side and then something to the other. He may even have a warped rotor in the rear.