Date:         Tue, 17 Nov 1998 19:47:24 -0800
Reply-To:     YauMan Chan <YAUMAN@CCHEM.BERKELEY.EDU>
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         YauMan Chan <YAUMAN@CCHEM.BERKELEY.EDU>
Subject:      Re: VC and waterpump ????sss
Comments: To: jjvantol@USWEST.NET, vanagon@VANAGON.COM
Content-Type: text/plain; charset=US-ASCII

Yes.. a constant drip is bad but as for the other part I beg to differ.  I know.. but Japaneses cars are different.  But we are talking about a VW Vanagon!
VW dealer were dealing with a lot of people bringing back their Vanagon back for water pump "leak" problems to have the water pumps replaced under waranty.  The following is a quote  from one of their Technical Service Bulletins to address this non-problem:

Technical Service Bulletin # 93-1, Dated 6/1/93
Subject: Coolant Pump Leakage
Models: All Water Cool

"Do not confuse a leaking coolant pump with one that is functioning as designed.

"Coolant pump seals are designed to use coolant as a lubricant.  This design intentionally uses a small amount of coolant to coat the seals during pump operation.  Any excess coolant that accumulates will exit the weep hole when the engine cools down.  ... coolant around the weep hole is NOT evidence of a faulty pump"   (emphasis theirs!)

The TSB then goes on to describe how to pressure test the cooling system before deciding to replace the water pump under waranty.  Now of course if it is out of waranty, I am sure the dealer will gladly replace it .. then if you bring it back with the same problem, they will explain to you that it is normal...

Yau-Man Chan - 3 water pumps later and a smarter water-cool Vanagon owner!
87 GL


>>> Joshua Van Tol <jjvantol@USWEST.NET> 11/17 6:27 PM >>>
Well, actually a steady drip isn't good. A properly functioning water pump
will only allow enough coolant to drip to form a stain. You should never
see wet coolant in or around the weep hole. On many cars (Japanese ones in particular) you won't even see a stain until about 60K miles are on the pump.

As far as the bearings being lubricated by coolant, that isn't the case.
They are usually sealed bearings, with their own grease supply. The water pump seal is the only part that benefits from the lubricative properties of the coolant. Coolant actually makes a very poor lubricant, thus the sealed bearings.
>>