Date: Thu, 26 Mar 1998 09:26:47 -0500
Reply-To: Dan Moy <danmoy@CYNET.NET>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: Dan Moy <danmoy@CYNET.NET>
Subject: Re: Coolant leak(again)
In-Reply-To: <199803261409.IAA01330@quicklnk.quicklink.net>
Content-Type: TEXT/PLAIN; charset=US-ASCII
John,
This is a common problem. There is a hairline crack in your expansion
tank. I had one in mine and I could not see it (at 84,000). Replacing
the tank solved the problem. At the same time I replaced the o-ring and
the cap to the expansion tank. I purchased the tank from the dealer for
less then $60.00 and it included the cap.
I suspect, part of the problem is that the expansion tank is right above
the exhaust system, which will add to the temperature cycling, hence
causing the tank to crack.
Dan Moy
danmoy@cynet.net
On Thu, 26 Mar 1998, John H. Rodgers wrote:
> -- [ From: John H. Rodgers * EMC.Ver #2.5.02 ] --
>
> A while back , on my '85 GL, I started having coolant leak problems at the
> expansion tank. I would drive a while, Then make a stop, and coolant would
> drip on the ground right under the expansion tank. . When I checked it the
> tank was wet on the outside, and there was coolant in the tank indent where
> the coolant level sensor screws into the tank. After a little more checking,
> I replaced the small hose from expansion tank to the overflow tank and made
> sure the passageway to the overflow tank was cleare, and cleared the vent on
> the overflow tank. I replaced the pressure cap on the expansion tank with a
> new one, and checked the expansion tank sensor to be sure it was tight and
> topped up the collant. Everything seemed in order.
>
> It ran fine with no leakage for a few miles but has started the same game
> again.
>
> It appears that either during warmup after a cold start, or after a highway
> run and suddenly getting into slow traffic when the cooling system is not
> cooling the coolant efficiently, sthe coolant expands sufficiently to try to
> force the overflow cap to open and vent coolant to the overflow tank.
> Apparently this is not happening, and the expanded coolant is forcing its
> way past the seal on the coolant sensor on the expansion tank.
>
> Is there a simple way to test this. There is the possiblility that the
> expansion tank has a crack somewhere that I can't see, that opens up at a
> pressure below pressure cap operating pressure, thus allowing some leakage,
> but with coolant around the sensor, I doubt it. The system takes coolant
> from the over flow tank, but never overflows back into the overflow tank.
>
> I am constantly adding coolant to the overflow tank, but I am loosing it to
> due to the leak. It never flows past the expansion tank cap back into the
> overflow tank. The coolant I use is the dreaded green stuff made by Texaco
> --- but it says on the container its specifically for aluminum engines.This
> was in the van when I got it. I still use the same brand. It's been 5 years
> and this is the only trouble I have ever had with coolant leaks.
>
> Comments would be appreciated.
>
> John Rodgers
> '85 GL Driver
>
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