> A check for assist can be made by first depressing the pedal several
> times with the engine off to make sure that no vacuum is in the system. 
> The brake pedal is then held down and the engine is started.  This
> should cause the pedal to 'give' and move down slightly. 
> 
> If the unit does not leak during the reserve check it is possible the
> problem then exists inside the booster unit.  With the brake pedal
> depressed and the engine running, listen for a hissing sound caused
> by vacuum leakage. If it cannot be heard, stop the engine and
> continue listening.  A steady hissing sound with the pedal depressed
> that goes away with the pedal released indicates a diaphragm or
> poppet valve (a thingy inside the booster) malfunction.  replacement
> of the booster is required to correct this problem. 
> 

Hi Dan.  Thanks for all the time you've put forth on this.  Your last 
paragraph is exactly what is happening with the Golf.  I called my 
dealer and set up an appointment for Thursday.  A new power booster 
is $499 (CDN), plus 2; hours labour to re & re.  It's not cheap.  I 
don't like the thought of getting a used one as it's about half the 
cost, and who knows what it came out of.  My dealer, who is just 
excellent, is trying to source out other avenues regarding the part.

Thanks for your diagnosis, and effort.  I'll keep you informed after 
the surgery.

Harry.
---------------------------------------------------------

Harry Yates     Internet: hyates@BCIT.BC.CA
'90 Syncro Westfalia
'87 Golf Diesel