You can also get the kit a an auto parts store. Lisle sells them. As a
vanagon owner you should have some means to test or at least know if the cap
is good and the system is holding pressure. Do the hoses get hard as the
engine warms up? They should! If you can squeeze a hose and have coolant
pass through cap and return when you release the cap is bad.

A check is to rev up the engine and look into the recovery tank. If you see
a steady flow of bubbles you are getting gasses into the coolant system. If
so the usual problems are cracked or loose heads. Now many will address this
by doing a head gasket job. The reality is that if the heads are leaking at
the cylinder to head seals it is due to the studs failing. The heads are
getting lifted off the cylinders under load letting the gasses into the
coolant. Left long enough the gaskets and head or cylinder surfaces get
burned or corroded. Either the last time the heads were off they were not
properly torqued or the studs are failing and need to be replaced.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Hector Zapata
Sent: Friday, May 25, 2012 4:28 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Pressure cap problem?

I'm having the same problem, I think exhaust gases are getting in the
cooling system in mine. You need to take your vehicle to a radiator repair
shop or a mechanic, and have them test your cooling system for exhaust
gases. They use a chemical that changes color if there's a problem. Good
luck.

Hector
1990 Carat 'Ursula'

On Fri, May 25, 2012 at 1:24 PM, Richard Golen <rgolen@hotmail.com> wrote:

> I think my pressure cap on my 87 is dead. Here are the symptoms.  Temp
> gauge is in middle. But coolant overflow tank fills up and overflows after
> 2hrs of highway driving.   When the van sits overnight the overflow tank
> still is full.
>
> Is the cap?
>
> Ric
>
> Sent from my iPhone
>