Date: Tue, 12 Feb 2002 20:56:58 -0800
Reply-To: Claudio Cella <claudiocella@SHAW.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Claudio Cella <claudiocella@SHAW.CA>
Subject: Re: '82 diesel water pump belt adjustment woes
Henry, i had a similar problem on my 1990 Jetta TD. In my case however it
was the alternator belt that was losing it's adjustment within say a couple
hundred kilometers. During the summer months (higher temperature) the
proper tension would last even less. After many months of trying to resolve
i found the problem to be the width of the belt itself. If i recall
correctly i was being sold a 10 milimeter wide belt where i should have been
given an 11 milimeter wide belt. Don't quote me on the 10 vs 11 mm as these
numbers could be out a bit. The bottom line was that the narrower belt was
riding lower in the pulley aand therefore the angled side of the belt would
not have enough bite to grip the pulley walls. This would cause the belt to
slip on the pulley even though the tension was adjusted. Once the belt
started to slip the belt would overheat, more heat yielded more wear and a
loose belt within a short time. Within a short period of time the belt was
shot. I don't know if this could be your problem as the adjusting system on
your water pump belt is different than the alternator belt adjusting
mechanism on my Jetta. Might be worth a look. Good luck.
1990 Jetta TD
1987 Vanagon GL 7 passenger
----- Original Message -----
From: "Henry Jackson" <hjackson@WELL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, February 11, 2002 5:23 AM
Subject: '82 diesel water pump belt adjustment woes
I have had SO much trouble keeping the crankshaft / water pump belt
adjustment correct on my 82 diesel westy. I get the belt tight by removing
shims on the water pump pulley and everything works ok for a few hundred
miles, then it starts slipping. I've replaced 3 belts (all high quality
Bosch) and one even wore so badly it lost all of it's "wedge" becoming a
rubber band.
I first smiled at the ingenious way the VW engineers figured out how to
adjust the water pump fixed solidly to the block with a single belt. But
removing the correct number of shims is a hit or miss guessing game and is
difficult to do in a tight space. I try to get it as tight as I can, with
maybe 1/8" available deflection at the midpoint of the belt span.
As far as I can tell the water pump shaft bearings are still good (no leaks
or noise)
Has anyone had similar difficulty and figured out a solution? Or am I just
not "getting" something and making an obvious mistake somewhere in my "water
pump belt adjustment" logic?
Henry Jackson
82 1.6 diesel Westy
Palo Alto, CA.