Re: 1987 BMW 325E Brake Pressure Build Up

On Thu, 24 May 2007 19:04:34 +0100, Oscar@xxxxxxxxxxx wrote:

On 24 May 2007 07:49:04 -0700, cbwillia0605@xxxxxxxxx wrote:

I am experiencing a problem where the brakes lock up after about four
to five miles of travel. I was told that the problem could be
resolved by replacing the master cylinder. I did, but the problem
continues. The only way to get going, is to release the pressure via
the bleeding valves. This works sometimes for an eighth of a mile or
sometimes up to ten miles. I removed all the relays from the ABS unit
with no luck.

Is there someone who has experience this problem? How was it resolved?

Brake vacuum servo is leaking................

When active in the trade I had a couple of cars in with similar problem of the
wheels (4) locking after a short drive. Releasing the pressure by the bleed
nipple as stated did get the vehicle mobile again but the problem in the first
was traced to a malfunction in the release valve of the brake servo not letting
air into the chamber when the brakes were released. Swapped out the servo and
no further trouble - DID NOT REPLACE THE MASTER CYLINDER.

Second vehicle with similar problems had a leaky master cyl and needed either a
new one or seals. We stuck a new one on and all was well for about 2 weeks then
another tow in for locked brakes so I swapped the servo and no problems with the
brake till the guy sold the car some 4 years later.

I agree there may be other causes but from experience it would be one of the
first places to look as a seized caliper would NOT lock all 4 wheels.
.

Relevant Pages

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