Re: Oil cooler gasket problem/ Disregard my valve cover gasket query

[jadney@vwtype3.org (Melissa & Jim)]

>From: Larry Edson <sonofed@ix.netcom.com>

>Don't crank the bolts/nuts down as far as you can.  When you crush the seals
>you end up shrinking the size of the hole for the oil to go through.  Then
>you have an overheating problem and overheating causes gaskets to get brittle.

This is one place where the Bentley manual is incomplete.  The earliest T3 
oil coolers used a T1 cooler and a right angle adapter.  I don't know what 
kind of seals they used--I have never seen one of these.

The second generation used the one piece cooler with integral oil pressure 
port that we are all used to, but it had 8mm inlet and outlet holes.  This 
cooler used the thicker seals, but also three thick aluminum washers, one on 
each bolt, to space the cooler away from the block so the seals would not be 
"overcrushed." You still need to tighten the bolts down to get 
metal-to-metal on the spacers.  This cooler also came with a sheet steel 
baffle plate that kept cooling air from leaking out from under the cooler.

Let's see a show of hands of how many people have ever seen one of these plates.

The latest cooler uses thinner seals, the same as T4 and late T1, and no 
spacers.  The seal is just reduced in thickness by the amount of spacer 
removed. This cooler has 10 mm holes and mates up with blocks with 10mm 
holes.  This is the best cooler setup.  The cooler itself is no thicker than 
the 2nd one, so it ends up sitting ~3mm lower when installed.  The mounting 
bolts should be tightened enough to bring the cooler into solid contact with 
the block.

Early and late blocks can be fitted with either 2nd or 3rd generation 
coolers by the use of special adaptor seals which are 8mm on one side and 
10mm on the other.  No spacers are used with the special adaptor seals.

Note that all the coolers (I am assuming this for the 1st gen) came with a 
piece of foam rubber glued to the top and around the top half of the outer 
end.  This may have prevented some vibrations with the cooling shroud, but I 
believe its main importance was to prevent cooling air from flowing over the 
top of the cooler and doing no cooling.  I replace this on all the old 
engines I rebuild with 3/8" medium density polyurethane foam padding.  The 
stuff I get here seems more durable than the original and is standing up to 
the test of time quite nicely.  A couple of these are 5+ years old now.

Jim
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       Melissa Kepner                                    Jim Adney
       jadney@vwtype3.org              jadney@vwtype3.org
                             Laura Kepner-Adney
                             Madison, Wisconsin
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