I joined the stuck caliper club

[89Ru]

1996 OBS, 170k miles, new to me last fall

On the way to work this a.m., my right front brake rotor is 400 degrees after short highway drive, feels warped (steering wheel vibrating at speed)

Pads are smoking!

 

This car doesn't have a hill holder...might be a collapsed flex line...will replace even if its not flat.

 

I'll grease the slide pins and pad-bracket surfaces, flush the lines, and attempt a caliper rebuild.

 

If this fails, where can I get a set of subie remanufactured calipers?

[RallyKeith]

What I typically see is where the piston dust boot fails and the piston itself corrodes and seizes. It's part of the problem of the salt belt we live in. Sometimes you can get away with squirting brake fluid in behind the boot and then working the piston in and out a few times and that will free it up, but that usually only last a few months. If that is the case, corrosion on the piston, rebuilding with a new piston only saves a few dollars over buying a remanufactered caliper from a parts store, and in my opinion the few dollars are worth spending. Getting all the seals in place and getting the piston back in can be a challenge, especially if you have dual piston calipers.

 

Keith

[Rooster2]

Yea, your caliper sounds bad............

 

IMO, you don't need to buy a reman caliper directly from a dealer. I have had no problem buying one from a regular parts store like Autozone or Advance. Also, any web based car parts biz should be able to get you one

[nipper]

Yea, your caliper sounds bad............

 

IMO, you don't need to buy a reman caliper directly from a dealer. I have had no problem buying one from a regular parts store like Autozone or Advance. Also, any web based car parts biz should be able to get you one

 

 

Yes calipers are safe to buy from anywhere.

 

nipper

[89Ru]

Thanks for the responses, I'll try the fixes and if unsuccessful, looks like I can get away with the local parts store or rockauto.

[Arty]

I have all rebuilt calipers on both my Subies. No complaints here

[vwbuge1]

I had a shimmie in the front end when I hit the brakes. Felt like warped rotors. I just took both my front calipers off. Removed the bracket and cleaned and lubed the pins/slides. I then used compressed air to pop out both pistons. Cleaned them up with some fine sandpaper. They were not all that bad. I then cleaned out the inside of the caliper, lubed everything and put it all back together. The toughest thing is getting the dust seals back in with the clip. Momma is sleeping so I will have to wait until morning to bleed and test.

 

If this happens again, I am heading straight to Advance Auto. Remans are $75 a piece.

[MilesFox]

I just did new brake pads and rotors on the front of a 95 legacy, just pads in rear.

 

the bottom slides on the caliper were rusty. I used silicone caliper grease, and anti-sieze. At first the brakes were dragging. I could smell hot brake pads. I pumped up the brakes a bunch of times each time i stopped, and parked the car at napa. when i came back out, the car drove normally with good brakes. The pistons hyper extend enough that it rusts and then seizes to its bore when it's pushed back in.

 

You could try pumping the brakes a lot, flexing the calipers, and flush out the old fluid.

[StructEngineer]

I tried Napa remans and they rusted like crazy

[vwbuge1]

I am done with them. Bled them out this morning and flushed with new fluid. Still a wobble in the wheel when I hit the brakes. I am going to have the rotors turned next although I don't see how they could be warped. I don't think they were sticking bad enough to heat that much.

 

I am so done with this car. Very disappointed. Maybe the newer ones are a little better? I was looking at the Outback XT and I was told to run.

[Rooster2]

I am done with them. Bled them out this morning and flushed with new fluid. Still a wobble in the wheel when I hit the brakes. I am going to have the rotors turned next although I don't see how they could be warped. I don't think they were sticking bad enough to heat that much.

 

I am so done with this car. Very disappointed. Maybe the newer ones are a little better? I was looking at the Outback XT and I was told to run.

 

 

 

Please, just calm down. Subies are great cars! When you over heated the brakes, the rotors were over heated as well, and warped. The wobble results from over heated rotors. Replace or have the existing rotors "trued", and your problems are solved.

[vwbuge1]

Please, just calm down. Subies are great cars! When you over heated the brakes, the rotors were over heated as well, and warped. The wobble results from over heated rotors. Replace or have the existing rotors "trued", and your problems are solved.

 

Even with the calipers sticking, I don't see how I overheated the rotors. There is no bluing on them or discoloration. I have never felt excessive amounts of heat at the wheel or smelled anything funny. I know Subaru's are great cars but this generation sucks rump roast. I plan on having the rotors turned or at least checked for run out before I mount the new calipers.

[johnceggleston]

any chance it is the rear causing the shimmy.?

[RallyKeith]

Even with the calipers sticking, I don't see how I overheated the rotors. There is no bluing on them or discoloration. I have never felt excessive amounts of heat at the wheel or smelled anything funny. I know Subaru's are great cars but this generation sucks rump roast. I plan on having the rotors turned or at least checked for run out before I mount the new calipers.

 

You ask and I shall explain. I'm not going to go into much detail but it works like this. The caliper sticks and so the brake pads are constantly engaged. This heats up the metal of the rotor evenly as the car is moving. The heated metal of the rotar is actually expanding ever so slightly until it hits the pads where it gets compressed slighlty. (This is why pads that are driven hard tend to be warn more on the incoming edge.) When you come to a complete stop the metal in the area of the pads is not allowed to expand and cool the same way as the rest of the rotor. This leaves a slight indentation, not visable to the naked eye, in the area where the pads were. This can happen with out the rotors ever getting hot enough to glow or blue as you mentioned. That little indentation is now your vibration. Racing cars I have first hand knowledge and experiance with this. That's why at the end of every rally stage we immediately pull the hand brake once the car has come to a stop.

 

Hope that helps explain what is happening and can also act as advice on how you can prolong the life of your brake rotors.

 

Keith

[vwbuge1]

any chance it is the rear causing the shimmy.?

 

not if I feel it in the steering wheel.

 

Rotors are getting dropped off to be turned. New calipers to be installed. Car is to be sold.

[89Ru]

You could try pumping the brakes a lot, flexing the calipers, and flush out the old fluid.

 

Not a bad idea, to break up some of the crud in there. I ended up removing the caliper piston which had only slight scoring plus rust and gunk, but then punted. The lower slide bushing is very difficult to move even after regreasing, probably rust reduced the ID of its booted housing. Since the pads have a tapered wear pattern after 35k, I'm going with new calipers rather than chewing through another set of pads.

 

Thanks to all for the help. The compressed air idea worked great to remove the piston, 25 psi no movement, 50 psi, nope, finally 75 psi blew it out, pop! Note to self, next time don't hold the piston on its way out.