Jere,

I have had AT fluid in my coolant (brownish sludge) since the first
differential cooler blew last summer. It never totally goes away,
although it is possible I am getting more in from a leak such as you
suggest. I don't know if I could detect a petroleum/oil leak in
addition to the AT fluid...

When the last cooler blew, I was driving on the freeway and the
transmission would no longer engage with the engine, leaving me
stranded.

I will ask to look at the  cooler; I'd like to see where the break is.

The rear heater core may be a weak point for high pressure, as 4 of
these have gone in a year.

Will start with the cap. Someone suggested about 14 psi pressure -
hope my mechanic knows the exact figure.

Thanks!
Paul

>Paul,
>
>IMHO you have a head gasket leak or an oil cooler leaking into the coolant.
>Why do I say that?
>
>1. it appears that your coolant is contaminated and the contaminate is
>eating the seals, petroleum products will eat the rubber.
>
>2. If your system was over pressurized it would blow out the cap (should be
>checked)... good chance this over-pressurization comes from something that
>can produce a higher pressure that is in the system.... One of the things
>that come in contact with the coolant system is combustion pressure (head
>gasket leak).
>
>Things I would check.
>1.  Look in coolant reservoir to see if there is a sheen on the surface of
>the coolant (you may have to take some out and put it in a clean bowl to see
>the sheen); and I would check the cap to make sure it releases at proscribe
>psig.
>
>2. if there is a sheen do compression check and check oil cooler.
>
>Thanks,
>
>Jere
>90 GL
>88 GL
>
>
>
>  -----Original Message-----
>From:   Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]  On Behalf Of
>Paul Cavanaugh
>Sent:   Thursday, June 28, 2001 4:41 PM
>To:     vanagon@GERRY.VANAGON.COM
>Subject:        4th heater core burst in 1 year!
>
>My 1990 (180k miles) GL automatic just had it's 4th rear heater core
>burst in 12 months!
>
>It also has burst two (metal) differential coolers, flooding coolant
>into and ruining my transmission.
>
>Any ideas what could be happening?
>
>My friends are urging my to give up the car (and I am tired of
>pulling up the flooded carpet)!
>
>Thanks!
>Paul

--
'90 Vanagon (180k)
'84 Vanagon (217k)
'78 Microbus (175k)