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First post.

I'm not the world's best mechanic, far from it, but I can normally handle brakes. Not these though. There is something really wrong up front, and for the life of me I can't figure out what.

Bought a 2001 Highlander a few moths ago from a soldier who was PCSing from Germany to Turkey. It was his wife's car, and she had great service records on it (which she wouldn't give me after the sale). But anyway, a generally well-serviced car. I knew it needed the brakes done when I bought it. No big deal, figured I could handle it.

Here's the general problem . . .

The front brakes were almost metal-on-metal when we took possession of the car. The outer rear rotors looked fine so I didn't worry about those. I replaced pads and rotors up front. No problem. Calipers looked good for a 10-year old car, still do.

The wife complained about 'squeaky brakes' a month later, so I figured it was time to do the rears. I got new pads and rotors because I'm in there anyway and have no idea how old those rotors are, so I'll just play it safe and swap them out.

Here is where it started to get strange.

I pulled 3 almost-brand-new looking pads off of the back, and one pad that was down well past the metal 'squeal tab' or whatever it's called. It was the piston side of the passenger caliper. That piston was about fully extended. Both calipers on back were pretty much frozen in place. I had to hammer one off. But eventually they came off . . . I put in the new pads, new rotors, greased up all the contact points, the calipers were moving freely again, and felt pretty good about things.

3 days later, the wife said the squeak was as bad as ever, if not worse.

So I looked the fronts again, and things were *definitely* not right up there.

The front brakes were basically locked up. I couldn't turn the front wheels at all. The pads were gripping the rotors like mad, the rotors had some pretty obvious heat damage (very dark in general).

I had to hammer the calipers off as they were mashed down on those pads so firmly. Weird. But ok, maybe somehow it was related to compensating for those frozen calipers in back somehow. I really don't know. Driver side pads looked OK, passenger side pads were obviously worn already (after being on for just one month).

Rotors will need to be turned, and brand new pads put in. But we're shipping the car back to California from Baumholder (Germany) in about 10 days, so that can wait I figured.

So I reset everything, put the pads back in, bled the system again. And drove off.

Today . . . same problem. The fronts are basically locked up. I can drive the car, but with basically the front brakes largely applied the whole time.

What could it be? What am I missing?

Could be 2 bad calipers, but going out at the same time? With no leaks? The backs *seemed* in much worse shape than the front, but they're moving freely now after being 'freed up' with a ball peen and grease.

I don't think it's a vacuum lock, lines have been bled twice now.

A bad valve . . . ? ABS problem? Ideas?

There is no Toyota dealer around, hell, might not be one in Germany for all I know. I have no clue what this is. Car is due to be shipped on the 26th . . . I could ship it as is, the driving will be minimal, but when it gets to Los Angeles then what? No, pretty much have to deal with it on this end before shipping.

So what can cause those front brakes to apply all the time? I'm thinking a valve somewhere, but that's just a guess at this point.

If you have suggestions, PLEASE feel free to suggest away.
 

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AvConsult
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3,552 Posts
Likely ABS issues. Apparently some ABS modulators develop sticky valves that fail to allow return fluid (after you release the brakes) to pass, causing the caliper to stay somewhat or severely applied. Mostly reported if the car sat for a few weeks or longer. My *guess* is that any moisture absorbed by the brake fluid over the years has a chance to form rust or deposits in the ABS.

You might try a 100% bleed at all 4 wheels, which would force fresh fluid past the modulator valves. While bleeding (with bleed nipple closed), use a c-clamp or something to press the caliper piston all the way back in, then press the brake pedal to extend the piston. Repeat that a half dozen times at each wheel. That will force fluid back and forth through ABS and maybe free it up again.

Never had an ABS unit apart to see about cleaning or rebuilding, but if it was that or toss it, I'd be tempted to take apart. Otherwise, check junk yards and secure a return policy if the used one is junk.

A new one from Toy is probably stupid expensive.
 

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Brake hose

My brother had a issue like that in a '91 Toyota Celica. Turned out the brake hose that supplied the front caliper had partialy colapsed internaly and was allowing brake fluid pressure in but not out!! So over time of applying the brakes it would build pressure in the caliper and appliy the brake on that one wheel all the time!
 
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