Perry:
The water pump bearings are a surface to surface seal with a spring loaded neoprene piece that turns against a ceramic wear surface.  Leakage in these seals is not uncommon, and does not necessarily indicate any real problem.   A bit of build up of engine sludge or a bit of grit will make them seep slightly.  This does not indicate a problem with the bearing, and often does not even indicate a real problem with the seal.    I have seen the telltale drop of coolant on virtually new pumps.   It is not a warning of impending failure..... if your pump is not old, don't worry too much about it.

H.W.


*********** REPLY SEPARATOR  ***********

On 8/4/03 at 9:07 PM Perry Mick wrote:

>Tracy Crook wrote:
>
> >Saw the first sign of waterpump failure on the engine.  Noticed a drop of
> >coolant hanging from the pump pulley every morning when I took the
>cowl off
> >to begin another day of talking airplanes & engines.  No noticable play
>in
> >the pump bearings and I noticed no drop in coolant pressure on the way
>home
> >but a new pump is definitely in order.  This was the original pump I got
> >with the 1988 13B engine I bought back in 1992.
> >
> >
> >Tracy Crook
> >
> >
>The water pumps went out in my '86 plane and my '86 car two years ago,
>so it is about right that your '88 water pump should be failing now.
>They last exactly 15 years :)
>
>--
>Perry Mick
>http://www.ductedfan.com
>
>
>
>
>
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