Date:         Mon, 4 Dec 1995 22:20:15 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         wabbott@mtest.teradyne.com (William Abbott)
Subject:      Heat exchanger wierdness

	Situation: The heat exchangers from Little Martha (70 single cab)
have no arms to operate the flap valves. Its apparent that the arms have 
been ripped off. A bit closer inspection reveals that the flaps are both 
installed *on the wrong side!*. That is, the remains of the arms are, on 
both flapper valves, on the side of the exchanger opposite the pivot for
the operating lever!

	So my beloved brother pried off one side's cover, as shown in
the Bentley book, and we discover that the flapper is retained by two
'c' shaped pieces of metal which are closed around the pivot. A little
screw-driver prying opens these and frees the flap. 

	You'll recall that the junk yard sold me two heater boxes
which have intact flapper valves + arms. Removing the cover from one
of them reveals that rather than a 'c' shaped retainer, the new-used
heat exchangers have solid pieces of steel tubing retaining the pivot.
Gloom. Then my beloved brother suggests taking the hacksaw and sawing the
little tubes so that they are 'c' chaped and can be pried open.... smiles :)

	The geometry of the situation means that I make some slices in the
edge of the arm that operates the flapper,. but not deep ones... considering
the small forces these normally endure anyway.

	So now I liberate the left side new-old flapper and install it.
Fits nice, even comes with little brass sheet bearing (strip bent into
a 'c' shape). Close inspection reveals that the flapper valves my
truck came with have big score marks on them from when the same hack-saw
routine was done to them- this is not the first time for this operation!

	A few minutes sawing frees the right side flapper, but when we go
to install it, the arm is on the wrong side! We double check the heat
exchanger, and there's no doubt it's correct for the right side of the
engine, but also no doubt that the flapper is for the wrong side!
	
	So Tuesday evening I'll have the local muffler shop cut the arm 
off the wrong side of one flapper valve and weld it onto the other side of
the flapper that was originally in the other heat exchanger. (They
were both wrong, remeber?)

	It looks like the right side flapper/arm geometry is more complex
than the left side, since the right side has to clear the starter
solinoid. The left side has the arm come out at 180 degress to the
flapper itself. Anyone care to advise me on angle for the right side?

	Meanwhile, how did I get a heat exchanger with the wrong-side
flapper valve welded into it??? Did I just hack-saw-up a rare and
priceless factory mistake? A dastardly East German forgery? Further
wierdness is provided by that heat exchanger not having a stud for
the operating lever to pivot on either. It's 'direct acting' like
the later type-IV flap-valves.

	All this will yield a kit for building a pair of heat exchangers-
someone having to put arms on the flappers and install them. Jim Brill  
wanted whatever I've got left over, assuming postage within reason, and
so he'll get 'em.

	Lesson? Use that hack saw!

	I've gotten good at prying off the covers, having now done 3 of 'em.
You pry on the outside, levering against the little tabs from
the body of the exhanger. You only have to pry-up the tabs on one side
to be able to force the other side off. Since the sealing discs are
cotter-pin retained, its obviously possible to replace them if they're
all that's wrong. I wonder VW last stocked 'em as replacement parts!
(I'll check the fiche tonight!)

	Somewhat bemused,
	Bill Abbott