Christoph,
The "bomb" is such an easy thing to change, it takes about a grand total of
about 20 minutes to do on my '87.
No, there is nothing you can push into the thing that will tell you if the
internal diaphragm is good - it appears that, over time, the rubber
diaphragm becomes (or _is_) permeable to the nitrogen. Over time, it leaks
out (either to the brake fluid, or the power steering fluid, or both) and
you lose the assist when the engine is off. The procedure for making a
non-rechargeable accumulator into a rechargeable one - one that, should you
lose the charge, you can get filled at your local heavy equipment service
station (pressure accumulators are used on backhoes/excavators/etc. - where
loss of hyd. pressure in an engine stall would also be deadly) is somewhere
on Audifans.com. With a discharged bomb (zero pumps of the pedal to total
loss of brake assist) all it takes is a drill, a dremel tool, a magnet (to
remove cuttings), the correct tap, and a high pressure Schraeder fitting
(get the one that holds over 3k psi). The one I have on my car was done by
Russ Southerlin (I hear he's not doing them anymore) - it hasn't needed a
charge since I got it a couple of years ago.
All the usual disclaimers apply.
Cheers!
Steve Sears
1987 Audi 5kTQ - rechargeable accumulator installed and working at a
fraction of the cost of a new one.
1980 Audi 5k - with the old school vacuum assisted brakes...oh, is that
_new_?
1962 and '64 Auto Union DKW Junior deLuxes - brake assist = long brake pedal
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