Rear Caliper Stuck, Red Hot Rotor. DIY gone wrong...Help!

kaj2003 · Post by **kaj2003** » 15 Jun 2010, 23:58

So I set out to change my rotors today on my T5-R to fix the high speed shaking (pads are still good for a while based on measurements). First time ever even touching something like this, though I have done plenty of other mechanical work on cars. I followed the guides on volvospeed and I thought I did everything right. Got the front rotors on allright. Drove around on those for a bit: no problems there. Then I set out to do the rear. I only had time to get the left rear done before rain started falling. Had problems with getting the outer piston compressed. In fact...it wouldn't budge at all. Being a noob, I just wedged the outer brake pad back in with a few loving whacks from my hammer and bolted everything back up. I should have thought twice when the wheel didn't spin freely...but I didn't. In hindsight, I probably should have done that, cause after driving to my friends house 5 min away (to watch the celtics get whooped), I lost pressure in my brake pedal and started smelling burned brakes. I got out in his driveway and looked at the back wheel and... well... I had an "Oh $@!%!!" moment. My left rear rotor was red hot, smoking like it was on fire. Nothing I could do to it then, so I went in and watched the game. The car is still sitting in his driveway.

What I wanna know is what the hell happened to make the piston stuck on the rotor? What did I do wrong? Have I damaged more than the pads, calipers or rotors? I've googled around a bit, and I haven't been able to find a thread with this problem.

My plan tomorrow morning is to take off the new rotor, and put on the old. Hopefully the thinness of the old will allow the wheel to spin freely. That'll be a temporary fix until.... well yeah...this is the part i dont know about. What's wrong here? What's my next step? Should I buy a rebuilt caliper? Should I just throw in the towel and take it to a mechanic?

kaj2003 · Post by **kaj2003** » 16 Jun 2010, 00:18

I should add that in the rear, I noticed that the outer pad was more worn than the inner pad. I've read that this is a sign of something wrong with the pins...but I don't get that. (so...Even though the pads were replaced not too long ago, I'm just gonna go ahead and order 4 new ones all around.)

Post by **polskamafia mjl** » 16 Jun 2010, 16:01

Well, for sure you should have stopped to think when you decided to hammer the pads in. I'm not sure what you did wrong, although it sounds like you somehow jammed the piston. Take the caliper off and see if it will compress easily; use a clamp or something like that. If it won't compress, rebuilding it or a new caliper are your only 2 options. The bigger question is exactly what you did or didn't do that caused the piston(s) to jam. Just out of curiosity, why did you hammer the pads in the first place?

Post by **JDS60R** » 16 Jun 2010, 16:51

Most of the time the seal between the piston sides and the caliper ( not the dust seat ) is hardened as it got old and needs to be replaced.

Rebuild or replace your caliper.

Post by **E Showell** » 16 Jun 2010, 17:23

Classic frozen caliper. Replace with rebuilt and pray you didn't kill your rotor (although you may have).

Post by **pkc303** » 16 Jun 2010, 23:09

I'd get a new caliper, and rotor. Sounds like you may have had one going bad for some time, so play it safe. Brakes are real important, especially on a T5-R.

Post by **vjaneczko** » 17 Jun 2010, 12:24

Rotors get hot, but not red hot - unless there's a huge problem. Toss the rotor and the pads.

The loss of pedal and the smoking was probably due to brake fluid escaping from the caliper. As mentioned, the seal can get old & brittle and cause problems.

The space between the caliper and piston is very small, so when compressing the piston back in, it must be done slowly and evenly or you can scar the metal and cause gaps where fluid can escape, even with a good seal. There are cheap 'Brake Spreaders' for compressing the piston back in - it's basically a long bolt threaded through a plate:

Brake Spreader from Amazon

Note: If you have one of these and you can't turn the handle by hand, it's a good bet the caliper needs to be rebuilt (yup, experience!)

If the seal was good before, the heat may have caused your seal to fail so you'll need a new one. You can rebuild a caliper yourself, but depending on the damage it may be better to get a new/rebuilt one.

Two other things to check since you're back there; e-brake pads and ABS sensors. If the rotor was red hot, the e-brake pads may have been affected. The ABS sensors usually get pretty dirty, so clean 'em up and dust off the ABS pickups.

Retired MVS Contributor · Post by **Retired MVS Contributor** » 17 Jun 2010, 13:20

Replae the caliper...The seal between the caliper and piston lets water in due to a tear or incorrect installation...Once water gets in, the piston and the cylinder bore rust and seize up...The caliper can be rebuilt, but inless you have the proper tools (cylinder hone, etc) it isn't worthwhile...If a brake job has been done before, the seal might have gotten damaged when the piston was pushed back into the caliper, a common problem on any car, not just Volvos...

850tech · Post by **850tech** » 17 Jun 2010, 16:07

The pedal went soft because the brake fluid started to boil (also know as brake fade) or the caliper you wedged back together started to leak when you nearly set it on fire.

Pistons not returning is a common occurrence, just replace both rear calipers with rebuilt. You'll definitely need rear pads and another rotor after that abuse as the heat cycle most likely damaged them both

Post by **patrioty3k** » 21 Jul 2010, 09:57

yeah,looks like i'll be doing the same on my right rear this weekend,been squealing more now, and the rotor looks scarred up...not a big job....I have to replace the front brakes on my sisters Jeep liberty on sunday,so It will be a nice "brake" yuk,yuk! especially in this great New England weather...