seized calipers - are my disks ruined?

[JeepCJ]

Originally Posted by someaussieguy

Here is a terrible photo of the pads and disk, what do you think? Looks glazed to me but the pads don't look ruined:

Looking at your pic's, the slide for pad looks OK. I have seen worse. The rotor is glazed but only needs a .005" skim & that'll tell ya it there warped. Sit a sheet of sandpaper on flat surface & scuff the pads but I'm not sure if R.A. didn't supply the correct callipers.

Recheck the dimensions between your old callipers with the newbies

[Morris4x4Center]

No matter what you do, I think it's a matter of determining why a caliper seized. (Both calipers? At the same time failed? That's like winning a lottery. Odds are against that)

Can the piston be free or taken out of the caliper at all? Maybe an inspection of the piston and inside the caliper might give an indication?


My fear would be it might happen again, even to a new caliper, without knowing why the previous caliper seized in the first place.

If you have an air compressor, usually a little bit of air in the bleeder hole will pressurize inside, and the piston will move. If it's free, there might be something else going on.


Just an opinion.

[Roler]

You still have your old pads?

[layback40]

Those disks dont look bad. Cant see any cracks & wouldnt expect to.
They dont look like they have been badly overheated, no blueing evident. Having seen the pics, I wouldnt be bothering to have them skimmed just yet.

I am far from convinced that you have seized calipers. you may have just had the smell & heat you get when new brakes are put in. Normally seized calipers lock wheels.
Attempting to move the caliper piston in & out will determine if you have a real problem. Remember the pistons are stiff in the calipers. It is normal to need a clamp to push the piston back in to the caliper bore. To get it to move out, if the hydraulics are still connected, just push the brake peddle down. A smear of brake grease on the piston wall is always a good idea to prevent seizure.
When they seize, it takes a lot of force to free the caliper/pad from the disk.
it doesnt look like there has been enough heat to kill the pads, if you lightly scratch a screwdriver across the pad surface & the pad material & its not crumbly, chances are the pads are fine.

I am just trying to describe what I would do if the jeep was mine. A brake place would just replace everything to be sure.

[someaussieguy]

Originally Posted by Morris4x4Center

No matter what you do, I think it's a matter of determining why a caliper seized. (Both calipers? At the same time failed? That's like winning a lottery. Odds are against that)

Can the piston be free or taken out of the caliper at all? Maybe an inspection of the piston and inside the caliper might give an indication?


My fear would be it might happen again, even to a new caliper, without knowing why the previous caliper seized in the first place.

If you have an air compressor, usually a little bit of air in the bleeder hole will pressurize inside, and the piston will move. If it's free, there might be something else going on.


Just an opinion.

Thanks for the advice guys, put it all back together, once the calipers are cold the piston moves freely, tried a bunch of stops, drove around for a bit all fine, until the brakes got hot again and the calipers started sticking again. Previous calipers were replaced only because they were old and I wanted all new brakes, they never had an issue, the lines are in really good condition and let fluid return so they are not the culprit.

I'm certain it's the new calipers, they are the right part numbers and same dimensions as the OEM ones, considering a mate of mine had the exact same thing happen to him with the same calipers from the same distributor, I'm fairly confident it's a bad batch. Also not keen to pull the caliper apart because I want to get them refunded and have proof I never disassembled them.

[someaussieguy]

Originally Posted by layback40

Those disks dont look bad. Cant see any cracks & wouldnt expect to.
They dont look like they have been badly overheated, no blueing evident. Having seen the pics, I wouldnt be bothering to have them skimmed just yet.

I am far from convinced that you have seized calipers. you may have just had the smell & heat you get when new brakes are put in. Normally seized calipers lock wheels.
Attempting to move the caliper piston in & out will determine if you have a real problem. Remember the pistons are stiff in the calipers. It is normal to need a clamp to push the piston back in to the caliper bore. To get it to move out, if the hydraulics are still connected, just push the brake peddle down. A smear of brake grease on the piston wall is always a good idea to prevent seizure.
When they seize, it takes a lot of force to free the caliper/pad from the disk.
it doesnt look like there has been enough heat to kill the pads, if you lightly scratch a screwdriver across the pad surface & the pad material & its not crumbly, chances are the pads are fine.

I am just trying to describe what I would do if the jeep was mine. A brake place would just replace everything to be sure.

Definitely wasn't just new brakes bedding in. Jacked the front end up and couldn't spin the wheels with all the force I could put on them, until they cooled down, then could spin them. Also, when driving home alst night the jeep was labouring, and the engine was running at about 110 degrees and transmission tunnel was super hot, struggling against the front brakes as they were locked on. I think you're right about the rotors, in the daylight they are still pretty close to normal colour, I'll rough them up with some sandpaper and see how they feel.

Also happy for anyone that's on the Gold Coast to come and check them out, not looking forward to the putting on the old crummy calipers.

Cheers

[Banshee]

Sounds like the pistons are slightly large so as they heat up, they seize in the caliper. Once they cool down they are free again? I'd go with bad batch if your mate had the same problem, and be talking to the place you got them from.