Both front calipers keep seizing even after replacement

[dholland57]

Originally Posted by Voodooskyline

Before jumping in to replacing list of parts based on guesses, have you actually established that infact the calipers are seized? generally speaking, if (rare for car that is driven on regular basis) and when piston inside the caliper siezes, it will not apply pressure to the pads when brake pedal is depressed. and it's highly unlikely that new caliper would drag like you describe. as far as the brake lines go, if there was blockage enough for it to apply pressure to the pads, it would not allow the fluids to pass to the caliper at the first place, but should it do that, you would be able to tell by swelling of the area before the blockage. I would first make sure the caliper is cause of the problem. you can check that by putting your car on the jackstands (all 4 wheels since it's awd) and rotate tire by hand and see if there is significant drag on that particular wheel. the brake pads are designed to skim across the rotors without pedals depressed so slight drag and noise is normal. however wheels should still spin freely. after you check that and compare wheel to wheel for variations you can pinpoint the origin of problem. I will help from this end as much as I can, also do you have traction control/abs on your car?

I took the car to my regular tire shop and they told me all 4 wheels are seized and that I have a hydraulic problem that they do not work on. They said there is a smell to the seizing. I have dealt with them for 10 years. Apparently when I 1st took the car there it was just the front seized, or that is only what they looked at, dunno. But, I had new front calipers, new master cylinder (bench bled) and new hoses and bled system in sequence. I was told it was fixed and I still felt violent shaking of steering wheel, so I took it back to the tire shop, thinking it might be a busted belt, tie rod end, or rotors. They also said it was not the rotors.

[dholland57]

Originally Posted by porcupine73

Hm...if both calipers truly siezed...multiple times....it is possible someone put something other than brake fluid into the reservoir at some point. I have heard stories of people pouring engine oil, and all kinds of other fluids in there, either accidentally or just not knowing, and that can eat up various seals and rubber in the brake system....

The person doing this work used to work at a Ford garage, he is currently an engineer at a power plant. I know what he did and that he put the proper DOT recommended brake fluid that I purchased with the calipers as I watched everything. He was very meticulous as to not get debris in or on anything.

[dholland57]

Originally Posted by Voodooskyline

Before jumping in to replacing list of parts based on guesses, have you actually established that infact the calipers are seized? generally speaking, if (rare for car that is driven on regular basis) and when piston inside the caliper siezes, it will not apply pressure to the pads when brake pedal is depressed. and it's highly unlikely that new caliper would drag like you describe. as far as the brake lines go, if there was blockage enough for it to apply pressure to the pads, it would not allow the fluids to pass to the caliper at the first place, but should it do that, you would be able to tell by swelling of the area before the blockage. I would first make sure the caliper is cause of the problem. you can check that by putting your car on the jackstands (all 4 wheels since it's awd) and rotate tire by hand and see if there is significant drag on that particular wheel. the brake pads are designed to skim across the rotors without pedals depressed so slight drag and noise is normal. however wheels should still spin freely. after you check that and compare wheel to wheel for variations you can pinpoint the origin of problem. I will help from this end as much as I can, also do you have traction control/abs on your car?

I think it is just regular ABS. I just had the brake hoses replaced. Same thing, now all 4 wheels are locked up. I found a technical service bulletin at NHTSA dated 12/8/04 bulletin # 10002989 summary: replacement of the electronic control unit for the ABS system repair. Where can I get one other than the costly dealership?

[Voodooskyline]

that is very odd, I've never heard of such problem, I could see somehow abs unit may faulty modulate and cause pedal vibration and noise, but I don't believe abs unit is able to apply and HOLD pressure at all 4 wheels. if I'm not mistaken it has failsafe system where should abs unit failure occurs it allows fluid to bypass for non-abs function. I would def get second opinion and perhaps resort to subaru specific service centers.

[grossgary]

wow, crazy. buy used parts. this stuff fails so rarely that new would be silly, i mean you're not going to even find another subaru owner with these symptoms or ever see it again so new is over priced.

car-parts.com is a junkyard database. if you can't find exactly what you're looking for (like an obscure part not listed or something) - look up something close - like ABS module...and if they have that, then they may have the controller, wiring etc.

disconnect the ABS electrical connectors or pull the ABS fuse or pull the ABS controller plug - or all of the above!

1. if the problem goes away then it's electrical in nature and the controller or relay likely needs replaced.

2. if the problem doesn't go away then the abs unit itself is probably mecahnically hosed inside.

two things i'm not sure about is if the master cylinder or proportioning valve could fail in such a way as to apply constant hydraulic pressure to the brakes?

i would suspect either the ABS module is mechanically hosed - replace it. it's fairly easy actually and not that big of a deal. unscrew fittings, install new unit, reinstall fittings. not that bad and while the "bleeding procedure" looks convoluted i've never really had to do anything but normal bleeding like any other brake component replacement, so not much to worry about.

did you try a google search - seems like all 4 locked wheels would be a symptom one other person has had before.

[porcupine73]

I hope you get it figured out! I don't mean the person doing the service putting the wrong fluid in the brake reservoir, I mean since you bought this vehicle used, you a previous owner may have done it.

Originally Posted by dholland57

The person doing this work used to work at a Ford garage, he is currently an engineer at a power plant. I know what he did and that he put the proper DOT recommended brake fluid that I purchased with the calipers as I watched everything. He was very meticulous as to not get debris in or on anything.

[nipper]

All four seized? I am guessing a master cylinder issue, a mis adjusted brake rod on the pedal. Some people like to adjust them which really sint suggested.

The ABS is passive untill it has to do something, so things just flow through it.

Not working on hydraulics? Thats a copout as brakes are not that complicated. Another possability can be collapsed brake lines.

[CNY_Dave]

Originally Posted by nipper

All four seized? I am guessing a master cylinder issue, a mis adjusted brake rod on the pedal.

Happens on motorcycles all the time- someone puts on hand guards that just touch the lever, keeps the fluid from flowing back.

Brakes heat a tint bit, fluid expands, brakes drag.

[highest_vision]

Originally Posted by highest_vision

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.

Did you try this? You have got to verify if there is actually residual pressure in the system or if there is a mechanical problem at the wheelend. If there is residual pressure, you can work your way back to the source by cracking fittings. Fluid in a system at rest will slowly seep out of a loose fitting. it should not 'pop' out as if under pressure.

James

[Wagondude]

Another thing to check is the lower slide pins on the calipers. Some of them have a rubber sleeve on the pin that loosens up and binds the pin in the bore. The sleeve is there to keep the pins from making a klunk as the brakes are applied. They can be replaced (the come in the pin boot kit). In a pinch they can be removed without affecting the opperation of the brakes.