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.


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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