the lesson I would take is that no cooling system o-ring should ever be
installed dry.
Even on a used o-ring ..
a high quality black silicone sealant...
( a very good one is Toyota's ) ..
and it won't leak.
( The Right Stuff is good too...in the caulking tube, not the aerosol
version )

Even factory assembled Honda's are put together with dry o-rings on their
thermostats..
and in about 6 years...they seep coolant there.  Talking to a customer on
the phone..I knew before ever seeing the car, that's that what they had
going on.

Scott
www.turbovans.com

----- Original Message -----
From: "John Bange" <jbange@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, January 02, 2012 9:47 AM
Subject: Engine swap lessons learned

> Finished swapping the engine out of my 90 GL with the screaming manual
> transmission (bad bearing), and into my 90 non-GL automatic (whose engine
> was making a Bad Noise). When I finally added all the requisite fluids and
> hooked up all the wires, it started right up. Ran it for a while, and then
> noticed a small puddle forming under the back. Coolant, or course. The
> water pump to engine case O-ring is no longer sealing. Never leaked
> before,
> when it was in the GL, but we all know that's what happens, right? I
> changed all the hoses, replaced the plastic 90 degree bend hose fitting on
> the right side by the pulley with a metal one, changed the fuel lines and
> injectors,and changed the ossified and leaking flywheel/flex plate crank
> seal and O-ring.
>
> So the lesson I've learned is, if you don't know when the water pump seals
> were replaced last, you might as well replace them if you have the engine
> out, even if they don't leak. I've just gone ahead and ordered a whole new
> water pump, because if I'm going to rassle with getting the old one off
> with the engine in, I want this to be the ONLY time I do it.