98 Jeep Front Brake Problem

[wn1998]

The wife had said that the jeep brakes were making noise so I swapped out the pads and put new rotors on my 98 grand cherokee.

When I swapped out the pads and rotors, the passenger side still had some life left on the pads, however the drivers side had nothing left and had actually ground in to the rotor. Also, one of the bolts that holds the caliper to the knuckle was rusted into the metal sleeve. I did get the bolt out of the sleeve and soaked them in PB blaster for about 10 minutes and then lubed them up with brake lube and replaced them.

However, when you brake the last 15-20 feet, the jeep has a minor "grab".

1. How can I tell if a caliper is bad? The plunger when back in with my C-clamp so I thought everything was ok..

2. How often do you have to change the rear disc's on a grand? On my wrangler, I change the rear drums 1 time for every three times I change the front discs. Could the rears need to be changed as well?

3. I have never bled the brakes after a simple front brake job before, does it need it?

Thanks for any help you can give me.

 

[Jimmy9190]

Usually when a caliper is bad or the piston is stuck the car will pull to one side when braking. If the piston is stuck the inboard pad will be worn down much more than the outboard and may have evidence of uneven wear. It could be the piston on the driver's side has some kind of problem where the c-clamp will move it back into the bore but the brake fluid can not. I have never had to bleed brakes after a basic pad and or rotor replacement either, but if the brake fluid has never been flushed it might need it now. It could be that the brake fluid has absorbed enough moisture that it is contaminated now and the brake system can not move the piston in the questionable caliper.

If this were my own vehicle I would replace the front calipers and do a complete flush of the brake fluid. You could take a look at the rear pads and rotors too. It's a possibility there is a rear caliper hanging up causing the excessive wear on the driver's side front brakes. I have no idea of the likelihood of that scenario. It has always been my understanding that the front brakes do the majority of the work in stopping the vehicle but I have never owned a car or truck that had 4 wheel disc brakes.

I spent a summer a few years ago working as an apprentice technician at a Jepp/Chrylser dealership. We saw a fair amount of Cherokees and Grand Cherokees come in for brake repairs, and IIRC probably 75% of the brake jobs were for the front only.

This is just my own opinion. YMMV and others here much more knowledgeable about brakes will have more info and suggestions for you. But calipers don't cost that much and you could just replace them and completely bleed the brakes and see how it does then. While you're at it you could replace the slide pins and dust boots to rule them out as causes of this problem.

 

[NYEngineer]

I agree with Jimmy9190, replace the front calipers and flush the fluid. On my Yukon, the slider hardware gets pretty beat after a couple of years. A package of the hardware is 14.00 and a rebuilt caliper is like 11.00 after I return the core. The calipers are so cheap, I just replace the whole thing every two years.
I also brush a little Nevr Sieze on the bolt where it goes through the tube.

 

[Jimmy9190]

Yeah they make special caliper slide pin lube, but anti-sieze will also work to lube the slide pins. I also coat the outer surfaces of the dust boots on my calipers with a light coat of regular old high temp grease and use a good coat of disc brake quiet on the pads.

 

[Jim Spahr]

I would first try to replace the caliper slide pins to see if that cured the problem. Use the high temp lube on the pins and other friction points. Be sure to clean out the bores they run in and replace the bushings and 'O'rings. Better yet, buy the hardware kit and replace all the front caliper hardware. Then you test drive it to see if there is any grabbing or pulling to indicate there is some other front brake problem. If it still exists, it is time for a new caliper. Since you replace in pairs, there would be two calipers and brake bleeding. When I say YOU test drive it -it is because some other drivers may not be as tuned in as you and may overlook a problem you would catch.