Air in the hydraulic system - yikes!

[Kunz, Bob]

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