Rear brake rotor stuck - need ideas

Gageraid · **Posted:** Tue Oct 14, 2014 9:26 pm

Try to knock off any rust you may find while in there.

Scar0 · **Posted:** Wed Oct 15, 2014 3:14 am

Sounds like your caliper pistons are stuck.
When the old brakes were on there the pistons sat farther out and probably collected a little dirt.
This is a very common issue when changing brake pads, because the pistons now sit farther inside the caliper.
Pull the calipers off, then pump the brakes a little to extend the caliper pistons out a little. Then gently pull back the rubber boot and inspect the sides of the pistons for corrosion/build up. Clean the gunk off and you should be good to go. The pistons are ceramic, so be careful not to scratch them.

lfhoward · **Posted:** Wed Oct 15, 2014 1:02 pm

Progress report: disassembled everything, cleaned up caliper holders (not sure what they are actually called) by wire-brushing out the brake pad slides and checking the grease on the slide pins, which is fine. Got the rotors and caliper holders back on and adjusted the parking brake tension properly. Next up, pads (with a good amount of grease in the slides), reinstall the calipers, and bleed the rears. Caliper pistons don't seem bad. Fingers crossed!

Question: Should I also bleed the fronts? Is there any chance air from the rear lines can get to the fronts?

Gageraid · **Posted:** Wed Oct 15, 2014 1:18 pm

lfhoward wrote:

Progress report: disassembled everything, cleaned up caliper holders (not sure what they are actually called) by wire-brushing out the brake pad slides and checking the grease on the slide pins, which is fine. Got the rotors and caliper holders back on and adjusted the parking brake tension properly. Next up, pads (with a good amount of grease in the slides), reinstall the calipers, and bleed the rears. Caliper pistons don't seem bad. Fingers crossed!

Question: Should I also bleed the fronts? Is there any chance air from the rear lines can get to the fronts?

I'm no expert on brakes, but I've never heard of someone NOT bleeding there brakes when changing them.
Did you see a lot of rust in the rear brakes?

lfhoward · **Posted:** Wed Oct 15, 2014 3:37 pm

Update.
Finished the job, did a better job bleeding the brakes this time so the pedal feel is normal.
The brakes are still dragging. :banghead:

The Jeep slows down coasting downhill and the brakes get hot and smoke.
Depressed. Thinking I will need new calipers or have it towed to a shop.

Scar0 · **Posted:** Wed Oct 15, 2014 3:54 pm

See my post above. It could save you some $. Pull the calipers off, remove the brake pads and do the above.

lfhoward · **Posted:** Wed Oct 15, 2014 5:09 pm

Scar0 wrote:

See my post above. It could save you some $. Pull the calipers off, remove the brake pads and do the above.

You are probably right. This is the only thing I haven't tried, because I was being cautious about damaging the calipers. Can you give me more details? How far should I pump the caliper piston out before removing the rubber boot? What should I use/how do I clean the piston once I remove the rubber boot? Thanks for your help.

tommudd · **Posted:** Wed Oct 15, 2014 5:30 pm

First if you are going to try and only push the caliper out so far ( something I would not recommend for most people) is to have a piece of board or something there to catch it. A stuck piston can be a huge PITA at times to pop out, one working as it should slides out fairly easy and can come out all the way ( if you don't have something to stop it. There is no way to clean one ( piston) really other than completely removing and cleaning the piston/ everything then install with new ring and cover
If you think it is a caliper that has a sticking piston, I would just buy new ( rebuilt) and be done

Scar0 · **Posted:** Thu Oct 16, 2014 4:46 am

What Tom says is true. The piston can pop all the way out real easy. It is a two person job, one at the brake pedal and one watching the piston (engine not running). Only do one side at a time.

Also, remember the piston was not sticking before you changed your pads. So you just need to get the piston out as far as it was with the old pads. If you still have the old pads around, you can use them as a stop against the disk (keeps the piston from popping out), then slide the caliper off the disk, remove the old pads, push the brake pedal ever so slightly to push the piston out just beyond where they were.
As far as cleaning, I use a little brake fluid, a toothbrush and muscles. lol Because they are ceramic rust is not a big deal, its just the dirt/ gunk buildup you need to remove.
If a piston does pop out, then it is best to get a "rebuild" kit. I have reused the old parts before, but it is a 50/50 chance they will leak.
Option 2 get a new/rebuild caliper as Tom suggested. One takes time, two takes more $.

EDIT:
This is a little unorthodox... I just did this on my daughters Cherokee.
One more thing you can try is to put a few drops of brake fluid inside the boot, then work the piston in and out several times(caliper off the rig). If it works, you will find it easier each time you compress the piston back in. It does not take a lot of buildup to cause a piston to get stuck. Don't forget to clean the fluid out of the boot once your done, or it will become a dirt magnet.

Worse case scenario, you end up getting a new/rebuilt caliper...

lfhoward · **Posted:** Thu Oct 16, 2014 4:33 pm

Today I picked up a set of remanufactured rear calipers at Napa for 20% off... Am optimistic this will solve the issue!

Scar0 · **Posted:** Thu Oct 16, 2014 4:50 pm

Cool deal.

lfhoward · **Posted:** Thu Oct 16, 2014 4:58 pm

Scar0, thank you for the detailed post on how to clean up brake calipers, even though I didn't decide to go that route. Posts like that are what makes LostJeeps so awesome. I'm sure it will help somebody down the line.

Scar0 · **Posted:** Fri Oct 17, 2014 4:18 pm

Your welcome. Forums are a great thing! I have learned more then I can remember from them.
Too bad more folks haven't discovered their benefits, and comradery.
.

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

Scar0 wrote:

Your welcome. Forums are a great thing! I have learned more then I can remember from them.
Too bad more folks haven't discovered their benefits, and comradery.
.

^^^^ What you said haha

lfhoward · **Posted:** Wed Oct 22, 2014 7:19 pm

I got the new calipers on today and bled the brakes! I'm still troubleshooting some tiny leaks at a couple of flare nuts on my new extended brake lines. One leak was due to a bur of metal that I didn't catch and remove the first time, after double-flaring the steel line. Hoping the second leak is due to the same, so I can clean it up and I don't have to re-flare it. Will find out tomorrow! It will be nice to have my Jeep back on the road finally. Dang, it looks like I started this thread on Oct 1! :dizzy:

Trying to remember all the :2cents:

I'm saving by doing this myself...

Scar0 · **Posted:** Fri Oct 24, 2014 12:36 am

Good news it that it is fixed. You also have the satisfaction of knowing you did it yourself!

lfhoward · **Posted:** Fri Oct 24, 2014 5:54 pm

Update:
Fixed the leaks! Got it all back together and it works! No brakes dragging and smoke!! Yay!
There are a couple of smaller tweaks left:
1) I am pretty sure there must be a little air in the drivers side line after driving it this afternoon. Need to re-bleed that.
2) The parking brake is adjusted too loose, so it doesn't hold the vehicle when I put it in D. I need to get under there and adjust the parking brake star wheels one more time.
Other than that, she seems good to go! I haven't tried any stops from going faster than about 30 mph yet, so she still needs to be road-tested outside of the neighborhood.
@Scar0, Yes, it is nice to know I saved a ton of moolah. I think I have about $350-400 in the project in parts & tools, including rotors, pads, calipers, and lines. How much do you think it would it have been to have this all done at a shop?

Scar0 · **Posted:** Fri Oct 24, 2014 8:48 pm

Typical shop rate is $60 - $120 an hour, depending on the shop.
Average "labor" costs tend to be about the same as the cost of the parts when it comes to brake rotors.
So you can say about a 50% savings, and now you know your rig better.

Greenwing7 · **Posted:** Sat Oct 25, 2014 1:18 am

Great job. It will probably be way easier net time too.
I had 3 calipers stick when I had my KK.

lfhoward · **Posted:** Mon Oct 27, 2014 10:21 pm

Thanks guys. Because this was my first time doing brakes and lines and I was a little nervous yet, I took my Jeep in to a shop today to have them double check my work. They said there were no leaks at the flares and no air in the lines, so we are good to go! :BANANA:

The mechanics were pretty complementary when I told them it was my first brake job ever.

It is nice when a project works out, especially one that was so challenging. I couldn't have done it without LOST, so thanks to everyone who weighed in to help me. :rockon:

Still got to adjust the parking brake tension so it actually works, but that should be no biggie.

Rear brake rotor stuck - need ideas

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