Pierburg Pump, Brakes, etc., etc.

[Alex Kowalski]

Hi everyone,

Since I'm the disreputable character who got everyone started on the
Pierburg pump craze (apparently) I can only say that I haven't had the
chance yet to install mine in the '87 5KCSTQ because of other issues.  As
soon as I get it in there with a new filter I will let everyone know exactly
how it works.

Since the weather has warmed up here, and I did my rear suspension and brake
calipers, and replaced my old, decrepit bomb with Dave Kase's wonderful
remanufactured one (highly recommended -- installation was as much of a snap
as you get with these cars) I have also discovered to my endless
consternation that I also have the infamous "brakes dragging when everything
is hot" syndrome.

I've taken the car out for several spirited rides since doing the work on
the rear end and the bomb, and one of the results was to get everything on
the car nice and toasty.  And with the warmer weather, this means that the
radiator cooling fan was doing its normal job, pumping hot, hot heat right
at the brake master cylinder.  Which in the warmer weather is now causing
the brakes to drag.  There are several posts in the archives about this.

I tested it in a similar manner, and with another (wierder) method:  first I
loosened the lines and got the fluid flow and the brake release to
demonstrate to myself that yes, in fact, the brake system was being
pressurized when it was hot.  Then I got a couple of those gel-pac cold
compresses, got everything hot again, waited for the brakes to stick, and
then wrapped the MC in freezing cold gel.  Voila!  After a few minutes the
brakes came loose (with the engine still running!) so I am 99 44/100% sure
the master cylinder is shot, too.  Not letting hot fluid back into the
reservoir, perhaps.  In any case, it beats the price of replacing the
servo.

I should have known.  The Audi Gods always get their tithe.

I'll do the M/C along with the Pierburg and give everyone a full report.

Cheers,
Alex Kowalski
'87 5KCSTQ -- Mostly done
'86 5KCSTQ -- Supposedly the "project" car.  ROTFL.