Air in the hydraulic system - yikes!

Jim Dupree jdupree914 at
Tue Jun 20 16:33:16 EDT 2006

Based on past personal and professional experience it
is probably your pump. The front seal can allow air to
be drawn in and pumped thru the brake assist circuit.
It is exaggerated by the screen in the reservoir
getting plugged up.
Good Luck

--- "Kunz, Bob" <bob.kunz at> wrote:

> Hi all,
> Been trying to diagnose this problem on my '86 5Ks
> avant. The first
> symptom was fluid overflow from the reservoir which
> I thought would be
> the accumulator not holding its fluid charge. Tested
> that out and it is
> fine.
> It appears that air is getting mixed in somewhere in
> the system. The
> return flow from the steering rack is charged with
> air since it bubbles
> up in the reservoir and causes the fluid to foam and
> increase its
> volume. The only explanation I can come up with is a
> leak on the vacuum
> side of the system which is really only the one line
> from the reservoir
> to the pump. I have replaced that line with no
> change.
> Could the pump itself be the problem? Perhaps a
> crack on the vacuum side
> of it? I can't think of anything else since the rest
> of the system is
> always under pressure. There are no leaks of fluid
> anywhere else. Of
> course the steering rack exhibits some air lock
> symptoms now (hard to
> initiate turns). Anybody BTDT and have a solution?
> --bob
> '86 5Ks avant
> '02 TTQR
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