Change that heater control valve now!!

[Paul Meyers]

OK, here goes. Answers to several questions about ye olde heater control
valve replacement:

>who makes those metal ones? (Gerard)
Autozone says that theirs comes from "Factory Air". From some old Internet
mail posts, these guys also sell rebuilt AC compressors. The Autozone part
number is 74671. My store in Orem, UT sells it for $13.99. It looks to be
cadmium plated metal on the inlet side and uses a metal valve body. The
outlet side connection is plastic.

>have you got a p/n?  thanx. (Bill Rowe) The Audi P/N is 431 819 809A. The
valve uniformly fails inside the valve body, where the hot coolant
eventually softens the black adhesive used to bond the two halves together,
so they come apart. And, since it's heat and pressure that eventually causes
the adhesive to fail, it usually fails at the worst possible time, when the
system is under maximum stress.
The Autozone P/N is 74671. 

>Can you post a procedure? Thanks. (Taka)
Sure. The valve is located directly at the rear of the engine, just in front
of the firewall. It's supported by the hose itself, so you just have to
loosen the 2 hose clamps connecting it to the heater hose to remove the
valve. Of course, when you do this, out comes the coolant (if you don't want
to lose it, better have something handy to plug or pinch the heater hose or
a bug bucket under the car). There is also a vacuum control connection
(connected by a braided hose to the white plastic vacuum line coming through
the firewall). Just pull the vacuum hose off and you're ready to install in
the reverse order. This would be a good time to change out the braided hose,
since, unless it's already been changed, it's likely rock hard by this time.

Paul Meyers 
Gray 87 5KCSTQ 1.8bar eurolights fuchs 145 kM, needs loom transplant 
Pearl 88 5KCSTQ 1.8bar eurolights fuchs bilsteins 125 kM 2pc-em k24 turbo 
Metallic White 87 5KTQW 191 kM daily driver w/ new heater control valve
Blue 86 5KCSTQ parts car