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RE: Brake fluid replacement

First, what do you mean by "brake hydraulic system"?  is this the :
         - Brake lines and reservoir using brake fluid?
         - Hydraulic assist circuit using Pentosin and shared with the P/S?

On the brake fluid, get a turkey baster and suck out all of the brake fluid
you can out of the reservoir.  Refill to the top with new fluid.  I like to
a pressure bleed system, where I have an air tank pressurized to about
15-20 psi; I have made up a contraption from an old screw-on reservoir
cap and a tire valve that allows me to pressurize the reservoir.  I then
off the brake fluid at each wheel (start at the bleed port on the master
cylinider!) until the fluid coming out is clear and free of bubbles.

On the power boost circuit, I have started out with the procedure with the 
turkey baster, then shortly run engine a few times to purge the fluid still
in the system up to the reservoir so I could draw it off.   I then filled the

reservoir to the top, and restarted the engine.  The system will basically 
fill and bleed itself; refill the reservoir as the fluid is distributed
the hydraulic components.  Once the system appears fill, slowly
turn the wheel from lock to lock to purge the last air bubbles out of the 
system (you should initially hear some whooshing/groaning as the air
is purged out, then the system should quiet down).

Good luck!

Ray Calvo (porsray@aol.com)
1990 Coupe Quattro  

In a message dated 97-02-07 12:13:00 EST, you write:

 From: Tim Reilley <treilley@gwi.net>
 Date: Fri, 07 Feb 1997 11:25:50 -0500
 Subject: Brake fluid replacement
 I checked the archives and was unable to find a procedure for draining
 and refilling the brake haydraulic system for a 1990 Coupe quattro or
 similar vehicle.  Can someone please write up a short procedure for me
 so I can know what is involved before I waste a lot of expensive fluid.