97 Outback front caliper issue

The subbie sat all winter and when I went to drive it the thing was a mess above 45 MPH. I thought it was tires that had acquired a flat spot but it never got better.

 

Been driving it daily and last Friday, after going for a drive, I felt the front wheels. The left one was normal but the right was hot. Ok --- something is up. I know that my rotors are warped but are they so bad that the car goes crazy above 45 MPH.

 

Today I installed new rotors and pads. Went for a 20 mile drive and at 70 MPH there is no crazy car stuff.

 

Arrived home and felt the wheels and the right one is still hot.

 

Errrrrrrr!

 

The caliper pistons (there are two) on that side looked darn crappy. And I am thinking that they are not working well together.

 

Not a fan of dual pistons because it doubles the chance of something sticking.

 

I thought that after pushing the pistons back in that maybe they would both work in tandem again. Now I am PO'd because there is the possibility that I heated the rotor and it could be a bit warped or starting to warp.

 

What's up with the dual pistons?

It sounds like one or both of the pistons are not returning to "home" and they are causing the pads to drag a little. If you can get a hold of laser thermometer I'd drive it for a bit and then see what the temp difference is on the rotor surface, if they are close (within 25 degrees or so) I'd say maybe there is something else hanging up, maybe a bearing or something, but I wouldn't know where to start without seeing the car though. If the temps are far off then I'd say the caliper is the problem and if that's the case, you can try rebuilding them or just replace them.

My son has a thermo but from my hand feeling the two front wheels there is a big difference.

 

Those calipers are cheap so I'll probably just buy one and install it. Can't remember if I can remove / install the caliper without removing the upper connection of the brake hose.

 

It sounds like one or both of the pistons are not returning to "home" and they are causing the pads to drag a little. If you can get a hold of laser thermometer I'd drive it for a bit and then see what the temp difference is on the rotor surface, if they are close (within 25 degrees or so) I'd say maybe there is something else hanging up, maybe a bearing or something, but I wouldn't know where to start without seeing the car though. If the temps are far off then I'd say the caliper is the problem and if that's the case, you can try rebuilding them or just replace them.

You have to disconnect the brake hose to remove the caliper but you can just as easily remove the mounting bolt for the hose where it's attached to the back of the caliper, so depending on how much the connections fight you to come loose, you shouldn't have to remove the upper one.

Went for a drive and checked with the laser thermo.

 

The sides are different temp. The one caliper was 50 degrees hotter and the rotors were 90 degrees different.

 

It is odd because the car stops fine and stops true....no pulling to either side.

 

If I remember when I did my Jag calilpers I removed the mounting bolt on the rear.

 

You have to disconnect the brake hose to remove the caliper but you can just as easily remove the mounting bolt for the hose where it's attached to the back of the caliper, so depending on how much the connections fight you to come loose, you shouldn't have to remove the upper one.

That definitely sounds like they are dragging a little, not fully seized but binding up. It's odd that they still work, calipers are weird like that. You can remove the caliper, and leave the mounting bracket in place and then just disconnect the brake line. Some companies don't supply a bracket with their new/re-manufactured calipers so I'd hold onto it if you need it. Plus it's only a single 14mm bolt to remove the caliper from the bracket instead of 2 16-17mm that hold the bracket to the hub and those bolts are always torqued down tight and are a pain in the butt to break loose.

Something is going on?

 

Then I started thinking that maybe the one side isn't working as hard and that is the problem.

 

Could also be an old hose that isn't allowing fluid to correctly travel.

 

I'm almost ready to do new caliber in the front and new brake hoses.

 

I can start with one caliper and see if that fixes things.

 

 

That definitely sounds like they are dragging a little, not fully seized but binding up. It's odd that they still work, calipers are weird like that. You can remove the caliper, and leave the mounting bracket in place and then just disconnect the brake line. Some companies don't supply a bracket with their new/re-manufactured calipers so I'd hold onto it if you need it. Plus it's only a single 14mm bolt to remove the caliper from the bracket instead of 2 16-17mm that hold the bracket to the hub and those bolts are always torqued down tight and are a pain in the butt to break loose.

If you get a chance, find an empty road and lock the brakes up just to see how they behave, my guess is that the working one will be compensating for the non working one. If I were you, I'd buy a new caliper and a new hose and then I'd put the car up on jacks and pull it all apart and then replace as needed and if you don't end up needing the hose or caliper you can just return them.

After the install I took the car for a drive to (as best as possible) bed in the new rotors and pads. After that I did try a lock up the brakes. I didn't drop rubber to the road but I came to a darn hard stop. It stayed true and straight on the road.

 

Because each caliper has two pistons maybe it is hard to find the one that isn't working well?

 

I don't think I've ever seen pistons and calipers that were as rusty as those on this car. There is so much rust under the car that I've theorized it is a flood car. I did a carfax and it didn't show up as a flood car but the title isn't clear. I figured it was an accident car.

 

But if the nobody reported the car being in a flood, no insurance claim carfax would never have it in their database.

 

 

If you get a chance, find an empty road and lock the brakes up just to see how they behave, my guess is that the working one will be compensating for the non working one. If I were you, I'd buy a new caliper and a new hose and then I'd put the car up on jacks and pull it all apart and then replace as needed and if you don't end up needing the hose or caliper you can just return them.