Boost, brake and AC problems

Henry A Harper III hah at
Wed Apr 9 17:50:52 EDT 2003

On Wednesday, April 09, 2003 3:46 AM, Jani Lundqvist
[SMTP:jl_76 at] wrote:
> [ Converted text/html to text/plain ]
> Greetings from finland

Greetings from Idaho!

> Been having few probs with my 200q 20v -91.
> 1.The brake light (red and flashing) does not go out. It comes on approx.
> 10-15sec. after starting and does not go out. When I turn the car off,
> pedal goes hard after few presses. Might this be the hydr.pump that's on
> way to hydr.pumps heaven or a faulty servo? Any good ways to check? With
> faulty bomb the warning light should go out by letting the car idle,
> it.

My original, dying/dead bomb does the opposite - "BRAKE" light (below the
trip computer, not the autocheck above) is lit for a few seconds after
startup and then goes out after idling. My BRAKE light also will flash if I
stomp the brakes while driving (I don't drive the car very often anyway).
Even a dead bomb, with a healthy pump and non-leaking servo, should not
light up the warning lamp for pressure reasons, IMHO.

> 2. AC-compressor is leaking. Is there any way to fix this, other than
> replacing the unit. Quick tour round AC-shops and cheapest bargain I
> find was $1020 excluding work, bit steep I should think. Is there some
kind of
> "leak-a-fix in bottle" on the market or is it possible to overhaul the
> compressor, shops told me it's not.

My compressor was leaking from the shaft seal since I got the car (damp
below shaft from compressor oil, hyd. pump not leaking), fixed it last
summer with a seal kit from - I think the model is
Nippondenso 10P17 as in this shaft seal here: and gasket kit here:  Various
light-to-medium shop tools required at my friend James' house - press, air
tools, etc. Refilled with R12 since he had a few cans left, worked great
all last summer. He has already converted his 200 to R134a (and we did my
GTI too, another shaft seal replacement after initial R134a fill) so I'll
do that when the R12 is gone. I think the o-rings on the back, double hose
attachment are "special to Audi" but mine didn't seem to be leaking and
were reused.

> 3. Not hitting 1.8 max boost. At WOT car starts to accelerate, trips
> momentarely at 1 bar, and continues to accelerate (and boost) up to
> bars (fluctuates). Tried disconnecting the MFTS, but to no avail. By-pass
> valve faulty? BTW, good place to order the Samco hose set TCS147. "Local"
> dealer in Finland offers it for $375 and what I've been reading, it
should go
> around $150 or so.

Any trouble codes stored in the Motronic fault memory? The dash guage is
not known to be especially accurate, and you likely won't see full boost in
lower gears anyway...bad MFTS or WGFV should limit you to about 1.4bar,
sounds like a leak somewhere maybe - see recent list descriptions of how to
make a (1-bar or so only) pressure-tester for intake tract.

Henry Harper  hah at
1991 200 quattro, 117k
1988 GTI 16v, 235k

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