Quick question on stuck caliper

[truckeejeeper]

Ok - so I just replaced my rotors and pads up front. Brakes worked ok before but were definitely worn. Drove about 10m and jeep started pulling to the left and smelled brake burning. By the time I could pull over and stop (1m) Smoke was coming from drvr side front brakes. Left jeep overnite to cool and got it home fine next day, just being easy on brakes.

So, if caliper locks when heated up, but releases when cold, is this a brake fluid issue? Moisture? It was just one side, and nothing else changed. Does this indicate it's not mechanical? Knuckles were replaced about 30k miles ago. VERY slight markings on new ones but not grooved really, and regreased contact points. Change brake fluid maybe?

One other thing, for about a year now, when jeep is off and I pump the brake pedal, I hear a "whoosh" of air, I don't remember that before. Or am I wrong. I sound like an air leak in the brake booster system, but I can't remember if that's normal or not. I don't see any leaks but need to dig deeper.

I did search for the stuck caliper issue but not much coming up for "releases when cold." It seems odd that it would just start happening all of a sudden with new rotors and pads. Calipers were fine before that. What's going on here exactly

Appreciate any thoughts thx much

 

[truckeejeeper]

Sorry - 1991 Sport 5 speed 4.0

 

[JonnyCat63]

Sounds like you have a bad caliper. I don't think the brake fluid has anything to do with it.

Sometimes when compressing the piston back into the caliper to install the new pads, you can damage the piston. Sometimes there is some rust/corrosion on the end of the piston, and when you push it back in, that rust gets into the bore and can cause the piston to bind. Or the piston was pushed back cockeyed into the bore, and jammed that way.

Either way, I think it is time for a new caliper, or trying to re-build your existing one. I prefer to buy new calipers as opposed to re-building.

 

[PacificEd]

Every time I've has issues with the brakes sticking on the front of my Cherokee's, it has been a rubber brake line issue. I replaced the lines and everything works as it should.

I've heard that when brake lines get old, they can collapse and hold pressure on the caliper. I have had this issue on other vehicles and every time I replace the rubber brake lines, it solves the problem and they work fine.

 

[truckeejeeper]

Ok JohnCat - so its not unheard of to have the piston start sticking from being pushed back to get the pads on, especially if the pads have been on for a while. And then it's probably time for a new caliper. Rt?? I didn't know that one time pushing them back would make them start to malfunction if they are old. But it makes sense as you put it, with rust/grime etc. There are about 40k miles on them, Centrics.

PacificEd- I will replace the line section there too. Put since this just happened when I did the pads, I'm leaning towards a stuck piston.

Any other thoughts def welcome

I'm looking at those Centric zinc plated calipers.. mine get rusty so fast.

 

[Unclewolverine]

I've had calipers stick on all types of cars after putting on new pads over the years. What I always do is take it back apart, pump the brakes until the piston is run almost all the way out, then run it back in with my big c clamp or whatever. Do that half dozen times and it cleans up whatever caused it to stick. It has worked every time for me so far.

 

[Old Man Minimalist]

Every time I've has issues with the brakes sticking on the front of my Cherokee's, it has been a rubber brake line issue. I replaced the lines and everything works as it should.

I've heard that when brake lines get old, they can collapse and hold pressure on the caliper. I have had this issue on other vehicles and every time I replace the rubber brake lines, it solves the problem and they work fine.

There is a good chance this is the issue. I learned the hard way. Rebuilt caliper, brakes froze. Replaced caliper and rotor, brakes froze. Changed brake hose, everything is sunshine and roses.

 

[xcm]

Are you guys seizing brake calipers using the proper spreader tool? Or are you using some kinda “LIFEHACK!” Trick?

I’ve seen quite a few videos of people using a pry bar… that’s a sure fire way to tweak the caliper piston.. if you don’t have a spreader, use a large c clamp, located close to the center of the recess in the center of the piston.

 

[Runnin'OnEmpty]

Every time I've has issues with the brakes sticking on the front of my Cherokee's, it has been a rubber brake line issue. I replaced the lines and everything works as it should.

I've heard that when brake lines get old, they can collapse and hold pressure on the caliper. I have had this issue on other vehicles and every time I replace the rubber brake lines, it solves the problem and they work fine.

Even with new calipers, my 96 still would stick
until I replaced the rubber hoses. After removing
the old ones, I tried blowing through them and
they were plugged solid. I think the inside rubber
degrades over time in these XJs. My 89 did
the same thing.

 

[XJI6191]

All rubber brake lines are prone to this, the walls delaminate & collapse, effectively creating a one-way valve: normal operating pressure will overcome it, but when you let the pedal off - the fluid can't return. Actually Jeeps seem to be better than most, lots of folk have had to deal with this issue, long before their vehicle gets to the age ours are.

 

[truckeejeeper]

OK great thanks for all the replies. Rubber brake lines are about 7yrs/40k miles old but will replace to be safe easy to try that too.

 

[truckeejeeper]

Ok, calipers replaced. rubber lines too. Best to just replace it all. Got a tip and used YJ lines. A bit longer for a bit more flex in the front. Everything working great now. Thanks y'all.

 

[PacificEd]

This is great news! Thanks for the update.