xjcherry

This is my 1989 cherokee laredo, 4.0 I6. After cleaning my wheels i noticed a severe build up of brake dust in a short amount of time. I just took my wheel off and saw the brake pads are rubbing against the rotor. I am definitely not an expert but im pretty sure its not supposed to be doing that.


Here are some pictures of the brakes because pictures are always helpful. Hoping there is a way to adjust them or easy way to fix them haha. Also wondering if anybody has any tips on cleaning the whole area.

PatHenry

The brake pads are supposed to be right up against the rotor - can you spin the wheel freely if it's raised off the ground?

An excessive build up of brake dust may mean that the caliper is sticking or is frozen. Typical causes of this include:

- stuck caliper pin - pull off the caliper and see if the pins move in and out smoothly and without a huge amount of effort. If one or both of them are difficult - pull the pins out, clean them up and re-lube them.
- pads getting caught in grooves in the knuckle. The proper fix for this is to weld in some metal into the groove and smooth out the knuckle surfaces to the original, flat level.
- frozen caliper piston - replace the caliper or rebuild it.

It's impossible to say what's going on with how your brakes look. There's some chipping on the edge of the pad, but that may be just a very old pad that has had rocks and gravel chipping away at it, or it could be the lining is damaged due to overheating or old age. If the Jeep is braking fine while you're driving it and not tugging on that side, I'd start by looking into the grooves or stuck pin first.

xjcherry

No the wheel does not spin freely. It takes a bit of effort to get it to move. I will check the pins and other parts you mentioned as soon as I can. This is my daily driver so i wont have an opportunity to take it apart for a few days. Thank you.

boxburn

Just be cautious especially if driving any real distances. If the caliper is having issues and it is the brakes binding, you can end up overheating the pads, disk, caliper, brake fluid (if enough heat gets to it), bearing.

xjcherry

I usually just drive around town (a couple miles) but I will be careful. Thank you.

dave1123

After you've been driving a while, stop and walk around to that wheel. You should not feel any heat coming off the brakes. All the heat from normal braking should be dissipated by the rotor. Check for mud or other stuff in the rotor vents. They look clean in your pictures.

DCWinterXJ

PatHenry is right on the money with all his suggestions. I have dealt with all of those scenarios. I don't know what tools you have access to but those calipers are really dirty. I use brake cleaner on regular level dirt but At that level I may use some PB blaster or wd 40...however I couple that with a wire brush and my air compressor to blow all the junk out. Once you clean it then you should check the pins and the piston. Pins are usually not to bad...pulling them and cleaning them if they are dry then regrease. Replace the boots that hold the grease in if necessary..the boots are like under 10 bucks at most auto places. And then there is the piston! Now I have had to replace calipers because of bad pistons and I have also been able to free them up with some exercise. You can push them in with a c-clamp and some wood....then when fully seated you can pop them back out by hitting the brakes...you should do this on a level surface if you can and monitor your brake reservoir by leaving it open, It should fluctuate as you exercise the piston. And make sure that whole area is cleaned and free of gunk. IF none of that works I would just replace the caliper. Rebuilds meh. Go on Rockauto and just get a new one. I just picked up 2 new calipers, new rotors, and new pads for my xj. Normally I would do that job but I am giving it to my mechanic. He is a good friend and I rarely have time to do certain jobs. Anyway good luck and dont forget youtube for a good video on all this nonsense!

dave1123

Just as a point of information, the only thing that retracts the pads from the rotors is the relaxing of the seals. They are square rings set in an angled slot so they twist when applied. When the pressure is released, they return to square, pulling the piston back just enough to clear the rotor. This is why everything must be free to move easily.

Idunno

While driving straight down the road does the truck want to drift towards the subject brake? If the brakes are applied does the truck pull towards that side? My 98 was basically track correctly but I could smell the acrid odor of an over-heated right front brake. The caliper on that side was not fully releasing and it was getting hot. Figuring them to be + 20 years old, off they came for new ones.

The way I change calipers I place a block of wood between the pads of the new caliper and force the piston out with a little air pressure. The wood block prevents popping the piston out completely, which is a bit of a PITA to reinstall if that happens. Then I fill it with new fluid and set it aside propped up to prevent dumping the fluid out. Then I carefully loosen the brake line on the old caliper and quickly swap it from the old to the new caliper. I lose very little fluid. Then I remove the master cylinder cap, press the piston back into the caliper cylinder and install it. It takes but a pump or two to bleed the new caliper. I think the cost of the new (rebuilt) calipers from Advance Auto was $46.00 plus tax after return of the cores.

xjcherry

After driving a few miles home I checked the wheel and felt some heat off of the brakes. Gonna clean them up tonight so I can get a better idea of whats going on. Wont be able to do anything past that for a couple days.