Left rear brake locked up.

EdMiller88 · Post by **EdMiller88** » 24 Jan 2013, 09:55

Pulling into my driveway last night I pressed my brake peddle only to hear this horrible grinding noise. This is the first time I've ever had this problem. I just got back in the car to drive and it's definitely locked up. The unbearable grinding noise is still there so I left the car parked. We've got artic temperatures in our area for this week which is unusual for my area. Could this be the problem? (Please note that it's not the parking brake, I don't use mine because I don't have any reason to) Please anyone else's input would be greatly appreciated! Thanks-

Post by **jblackburn** » 24 Jan 2013, 10:03

Heavy salting and rust probably killed the caliper.

You can buy re-built calipers at your local Autozone. Replacement isn't very difficult for even a beginner DIY mechanic (well, aside from the rust on everything).

EdMiller88 · Post by **EdMiller88** » 24 Jan 2013, 10:11

Well I take great care of the car there's hardly if any rust at all. I figured it was the caliber but the auto parts stores are saying a week for the part. Much too long to wait

Post by **jblackburn** » 24 Jan 2013, 10:20

Volvo's don't rust, but the undersides do a bit.

It's also possible the parking brake pads have fallen off their backing and jammed in the rotor...it does happen every now and then to these cars.

You could take the rotor off and try lubing up the slides and blast any salt out from around the piston. Check to see if the dust boot is torn.

Post by **cn90** » 24 Jan 2013, 10:21

Spray some WD-40 or PB Blaster at the hard line + caliper junction. It is usually rusted in, making removal very difficult, if not impossible.

You may need to use heat (Propane torch).

Info in forum.

Post by **850 LPT** » 24 Jan 2013, 11:02

jblackburn wrote:It's also possible the parking brake pads have fallen off their backing and jammed in the rotor...it does happen every now and then to these cars.

This has actually happened to my car, and yes, it makes a pretty nasty noise. On both sides the the parking brake shoes were shot. And I don't think it matters if you use the parking brake or not. The lining just separates with age. The only way to know if it this or the calipers is to take the wheels off and inspect. Hopefully you have a garage.

Post by **rmmagow** » 24 Jan 2013, 11:17

If you do decide to replace the caliper, be sure to replace both sides and bleed properly. If you find the brake pad has worn and this caused the locked brake condition, put on new rotors too. But as mentioned here, check that parking brake first to be sure it didn't fall apart. You are going to have rust under there, so prepare for it.

Post by **Ben850** » 24 Jan 2013, 15:38

I put new rotors on all around recently, and when I was maneuvering my right rear onto the spindle, one of the linings popped right off of the parking brake shoe. It didn't take much. So I could imagine they could come off by themself with age.

Post by **JimBee** » 24 Jan 2013, 19:36

Like cn90 said, the steel line into the caliper can be rusted pretty tight. That fitting btw is not metric. It's been a while, but I think it's 7/16 (or 3/8). You'll need a box wrench with a gate for best grip on it.

I put a circular wire brush in my portable drill and clean the exposed threads and around the caliper at the fitting. Then hit it with PB Blaster, ideally over night, then again and wait a bit. Sharp force against the wrench could strip the corners off the fitting, steady, even force is better. If you strip it a vice grip with sharp teeth is your only option.

Post by **Ben850** » 24 Jan 2013, 21:46

It is in fact 11mm. I tried 3/8 and 7/16. It is also very hard to find a line wrench, ( flare wrench) in 11mm. I ordered mine online.
http://www.ebay.com/itm/390340472807?ss ... 1439.l2648

I have yet to return to the frozen line fitting. I have since replaced both front rubber lines with stainless, and the 11mm comes into play up front where the flex line meets the steel line.

The wire brush is a good idea. PB Blaster, heat, and there in also an extreme cold spray that contracts the joint area to allow penetrating oils to seep in.
Some models may differ depending on year, but my 850 rear caliper, steel line fitting was indeed 11mm.

Let us know what caused your lock up when you find out.