Date: Tue, 14 Mar 2000 09:50:57 -0500
Reply-To: vw4x4@FYI.NET
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Eric Zeno <vw4x4@FYI.NET>
Subject: Re: Head gasket again...
HI rich,
I can't stand doing a job like this twice, so I feel bad for you.
As for a compression leak: there is only two reason for this. One
is a crack in the head. Make sure the machine shop is using the
special chemicals required to find cracks in AL heads. I honestly
don't think this is the problem as, somewhere I had seen that
small cracks are exceptable for rebuilds.....go figure???
The second reason compression leaks, is the surface at the top
of the cylinder is not true to the head. Heads can warped because
of excess heat, machined uneven, there could be a sealing ring
from the previous rebuild left in there....BTW do you replace
these compression sealing ring? Also the two cylinder side by side
must be completely true to each other. IF you pulled them from the
block, at all, I would put a square across the top of them to
check there flatness. The machine shop should have check the head
to ensure the sealing surface in each cylinder is flat to the other.
Don't assume this. Use new sealing rings. I would not reassemble
until you find the cause for this. When you do, torque to specs.,
and then add a 1/4 turn to the wrench. You will not have any more
compression leaks.
Eric
> From: Richard Bias <rbias@HOTMAIL.COM>
> To: vanagon@GERRY.VANAGON.COM
> Date: Tue, 14 Mar 2000 06:00:19 PST
> Subject: Head gasket again...
>
>
> Good morning All,
> I am looking for a little re-assurance (if possible) and some advice. I
> am currently doing my second head gasket replacement in the six or so months
> I have owned our Vanagon (1985, 8 passenger, 1.9L, White GL). The first
> head gasket job came when I sprung a leak to the outside world of streaming
> blue coolant. I cleaned the heads and the cylinder barrels myself. I was
> extremely careful to do a precise job, took close to a month, with more than
> a couple of "all day'ers". I took my time as this was my first time with a
> water cooled. I had a Bus in HS that I did a lot of successful work on the
> engine, brakes, clutch, front end (don't ask), body... My current situation
> happened on a 700 mile trip to Pittsburgh. I had compression pressure in
> the coolant system. I understand that I may have not had the heads "sand
> blasted" cleaned the first time but how does the compression head gasket
> leak? I just brought both heads to the shop and they got the OK on the
> pressure test and there is very little to no pitting (I know what a pitted
> head looks like too). Why do you suppose they leaked?
> Second question, What do you lubricate coolant hoses with to make them
> slide on their male flanges easier? Thanks for any words of wisdom and or
> support.
> Rich and Annemarie
> 85 GL "Buba"
> 98 Bug
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