RE: 87 5kcstq- Weird symptoms: hydraulic problem?

["Sheffield Corey" <SHEF@omdc.gso.uri.edu>]

>1)  After 15 miles of 80 mph driving + 5 miles of stop-and-go + another 5
>miles of 80 mph, a front wheel shimmy becomes apparent through steering
>wheel vibration. It *feels* just like a wheel balance problem.
>
>2) The shimmy gets worse for the next 10 miles of 80 mph stuff, then goes
>away, but braking now requires stroking the pedal almost to the floor, the
>triangular brake warning icon in the instrument panel illuminates, and a
>warning "PEEP" sounds off. Braking effort is increased, but not by a lot.
>
>3) After another 5 miles of 80 mph and 5 miles of surface street driving,
>between one stroke of the brake pedal and the next, the pedal is again at
>the top of its travel and all symptoms are gone for the rest of the drive.
>
>It sounds like a hydraulic problem to me, perhaps accumulator and pump both.
>What's the collective wisdom of the rest of you Q heads?

Hi Larry,

	I'm only guessing, it hasn't happened to mine...yet:-( But you may have
a failing master cylinder. I believe, from previous posts that they are a two
piece plunger affair, and if one of the pistons is sticking it could be leaving
your front or rear brakes stuck slightly on causing you shimmy...although, I
always thought the brake warning icon was pressure related. Maybe when the
piston sticks it allows the pressure to bleed out of the "bomb". A lot of
supposition here, Larry. Does it pass the "bomb" test when working properly and
fail when the symptoms appear?? At least that might limit your search by one
component.

HTH,

Shef

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