I've been down this road with my '84 318i.  The first possibility to explore
is that the leak may be happening because the hose clamp at the top end of
the hose under the reservoir may have become loose due to the rubber
shrinking from age.  This is a definite possibility if your car still has
the factory crimp type hose clamps which cannot be tightened.  The best
evidence of a leak at this location will be that the hose will be caked with
road dirt that has stuck to the wet hose.  Replacing the hose clamp with a
screw type will solve the leak if this is the cause.

Hi everyone,
I have a 1986 BMW 325es and I noticed that the power steering fluid
keeps leaking. I looked down and there are two hoses that come out of
the end of the resorvios, one goes to the front of the car and the
other one goes towards the steering of the car.
I looked down and the hose that goes to the power steering pump (close
to the radiator) does not leak but, the other hose that goes to the
steering culumb (I think) is the one that is leaking. Now, I do not
see the actual leak, I think I need to get under the car and check it
out.
My question is this, is it possible to get undet there and see if the
hose is busted and replace it or, it is something that a mechanic can
do( needs special tool, car needs to be lifted becase there is not
room under the car).
Has anybody done anything like this on these models? Is it easy to do?
Is ehre a picture of this somewhere where I can look and find out what
I am up against before trying to get under the car?
By the way the car is 5 speed and in US.

Thanks a bunch?