Both front calipers keep seizing even after replacement

[dholland57]

Hi! I have a 2000 Subaru Outback LTD with 145K miles, 2nd owner of 2 yrs. I retired 8/19 and since drive infrequently. About a month ago I heard a whoosh sound when I applied the brake after backing from my driveway. Continued and no more sounds and everything seemed normal. I have since heard the noise on only 1 other occasion, same scenario. Then, 2 wks ago my check engine light came on and I had the auto parts store run a code. Told me it was knock sensor. I had it replace by a friend who used to work for a Ford garage. As I pulled to his garage for the knock sensor install, he said he smelled something burning and held his hand by driver's side wheel. He said the brakes were locked and both sides of front were very hot. I then drove 20 miles to and fro to get new calipers. Put them on and bled brakes, still stuck. Then I went just a short distance and got a new master cylinder. Today put that on and re-bled the entire system in sequence starting from furthest brake to closest brake in relation to master cylinder. Test drove and seemed fine and then as we returned to the garage, seized up again. Previously tested brake booster and all seems fine there. Help!

[xvimbi]

Not sure how exactly you did your brakes, but wanted to mention that Subarus are notoriously picky when it comes to replacement parts. Brakes seem to be one of them. Don't go with cheap pads or anything else, or you'll be replacing them again (and again). I think using OEM parts would be wise in this case. That might do it.

Perhaps that helps:

You Tube

You Tube

[highest_vision]

Don't forget about your flexible brake hoses. You don't need OEM calipers, pads, or rotors, but the caliper pins should move easily and the pads should move freely.

You can tell if the hose (or something else) is holding pressure by loosening the bleeder screw on the caliper. Fluid should not spurt out. If it does, something before the caliper is amiss. If not, something at the wheelend is.

James

[porcupine73]

+1 on the flex lines. Sometimes they collapse inside, so they will act more like a check valve, letting fluid into the caliper, but then not letting it back out.

[shortbed rv]

This may be hard to determine but does the brake light come on when this happens? Could a faulty traction control send a signal to brake this one wheel?

Just asking.

[subigt]

New calipers will get you new pistons that are unseized in their bores. But if you install these new calipers on your old slide pins which are still seized into your old support bracket, you will still have a seized caliper. Ask me how I know

[1 Lucky Texan]

a 'flapper' inside a hydraulic hose can hold/limit pressure release but I think the odds of it happening on both sides approaches infinity.

Some folks have had to grind off a little of the 'ears' on pad backing plates to prevent dragging after a little rust develops.

In addition to good suggestion from others, perhaps, due to a wreck or??? some work has been done on the front of the car and one of the following has occurred; wrong size/model brake caliper BRACKETS were installed, wrong rotors were installed, aftermarket rims are rubbing on the calipers(unlikely I'm sure)


just some wild guesses.

[Toy529]

+1 on Flex hoses

[dholland57]

Installed new slide pins, too.

[CNY_Dave]

Originally Posted by 1 Lucky Texan

Some folks have had to grind off a little of the 'ears' on pad backing plates to prevent dragging after a little rust develops.

I've had to do a bit of grinding just to get them in... and that's after cleaning all the mounting surfaces and the clips/shims.

Good pads, cheap pads, almost always have to grind.


Dave