Date: Thu, 15 Nov 2007 20:07:52 -0800
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: Leaking Head perment fix ??
In-Reply-To: <0ed601c827ea$33c6b470$0a00a8c0@OWNERMIKE>
Content-Type: text/plain; charset="us-ascii"
Are you saying excessive amount of sealant on the 'water retention' gaskets
of waterboxer engines will keep proper torque from being allied to the
gasket ????
If you are, sorry, can't buy it. Any excessive silicone sealant will just
get squeezed out. It's not like old coolant sitting in the bottom of a head
bolt hole on an inline upright engine, , where it can't easily escape.
I've had to pay very close attention to how much that rubber water gasket
is squeezed.
Too little and it will leak, too much and it will get pinched and split and
leak.
The 'step distance' between the flat bottom of the head, and where the metal
sealing rings sit, in the combustion area, determines how hard the water
gasket is compressed.
You must put the head on without the water gasket, with the metal rings
in place and measure what the gap is that the water gasket needs to seal. .
Last time I dealt with this, I measured the water gasket at 3.5 mm thick.
It needs to be compressed at least half a millimeter. I've seen the gap
vary across the top of the block there as badly as 3 mm on one end and maybe
6 on the other end - how ya gonna seal that !?
Anyway...it's not excessive sealant keeping the head from seating down
well enough on the gasket, if we are talking about the same thing here.
Scott
www.turbovans.com
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Mike
Sent: Thursday, November 15, 2007 4:47 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Leaking Head perment fix ??
He says, "3 split head gaskets in 4 months"? Sounds like a 'mechanic'
that didn't know what he was doing. ANY gasket will split (some call this
'hydraulic'ing) by applying excessive wet (un-cured) sealant, then promptly
torqueing the part down tight. As fluid is non-compressible (silicone is
fluid before it cures), this causes the too-large amount of sealant to need
to find room to go somewhere, splitting the brand-new seal. The mechanic
needs to use the exact gasket or seal, using the exact type and amount of
sealant (or lack thereof) as specified in the manual. Varying from this
exact procedure WILL give you problems, one way or the other........
Too many well-intentioned 'mechanics' have made this mistake; "I don't
want this thing to leak again, if some is good, then more will be better".
WRONG! And thinking that you can out-engineer the factory by inventing your
own gasket/ sealant/ torque values, is also just plain wrong! His limited,
'worked-great-for-me' repair is really pushing things, to recommend it to
others. And since when does a thicker gasket require a higher torque? I
don't know what this guy's smokin', but it must be good stuff. Allowing the
silicone sealant to cure first, before full and final torque is a good idea.
I recommend using a correct, quality gasket and sealant kit, applied and
torqued 'exactly' as directed. This will most likely result in a
long-lasting, no-leak, permanent repair. I'm NOT saying that factory did
this perfectly right, but I AM saying that it's your only right way to do
it. It has lasted many hundreds of thousands of miles on many engines for
many years, so something there must be right.............
Mike B.
----- Original Message -----
From: "TC" <trclark@SHAW.CA>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, November 15, 2007 12:10 PM
Subject: Leaking Head perment fix ??
> http://www.thesamba.com/vw/forum/viewtopic.php?t=264403
>
> they suggested their 1/4" hi-temp silicone sheet & make some.(RED) 2-3
> tries
> to get pattern correct & cut easily with exacto knife-go slow. cut 1/4"
> larger than o.s. of head & no holes covered.clean gasket mating surface &
> run narrow bead of silicone around incenter-center gasket on head & place
> board on with a weight(brick etc)until cured.check seal position & place
> on
> board seal down-trace o.s. of head with pen.place head,prod tubes inplace
> &
> instl head touching block. NOW check tracing--if still ok seal in correct
> pos.torque heads with BEAM wrench-ADDING 5 lbs as gasket is 50thsnd
> thicker.
> myne been on 11yrs with a cyl seal replace 3 yrs ago/reused seals.2 other
> wbxs had same & run 2+ years each.use your own judgement as tothis
>
> comments ???
>
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