water pump leak
The original equipment water pump on the 5432 is an Oberdorfer unit with a grease cup that must be tensioned frequently. If the grease cup runs to empty or hasn't been tightened regularly, the seals will wear out and it will leak. If yours isn't one with an oil seal as well as a water seal, then when the water seal leaks it is possible for water to leak into the crankcase.
I replaced the original Oberdorfer with a semi-custom water pump sold by Moyer Marine. Moyer makes water pumps (and other parts) for Atomic 4 gas engines. It turns out that the 5432 uses the same water pump as the old Atomic 4 so the Moyer unit bolts right up.
The Moyer unit does not have a grease cup. It uses permanently lubricated bearings instead. It also has two seals, one for oil and one for water. The water seal will wear out before the oil seal resulting in water leaking from the weep hole on the bottom aft side of the pump body casting. This leakage indicates that it's time for new seals and maybe new bearings. The other advantages of the Moyer water pump are that it has thumb screws on the front cover and uses an 'O' ring instead of a gasket on the front cover. It also has no 'jesus' clip retainer on the impeller end of the shaft. All this means that impeller replacement is greatly simplified and can be accomplished in minutes since all that needs to happen is opening the case via the thumbscrews, pulling off the old impeller, slipping in a new one and buttoning the thing up again. It also pumps more water than the stock Oberdorfer.
On the original Oberdorfer, you had to remove the cover (sealed with a paper gasket) remove the spring clip from the shaft end, hold the shaft in place with a dowel or similar and pull the impeller at the same time over the dowel (or screw driver, wahtever). If you pulled the impeller without holding it in place the shaft comes out of the seals, then you are faced with removing the entire pump, replacing the impeller, shaft, seals etc because the seals go on last over the shaft and they are on the engine side of things.
Of course you need to have spares on hand but in the case of the Moyer unit, you can reuse the o-ring where with the original, your spares kit needed to have a gasket (or permatex) as well.
In any case the Moyer is a great set of improvements to basically the same pump.
There is also a Sherwood conversion pump available (check with Torrenson Marine) that pumps still more water. I think the stock Oberdorfer pumps at something like 2.5 gpm, the Moyer at about 3.0 or 3.5 gpm and the Sherwood about 5 or 6 gpm if memory serves.
Moyer's website is
http://www.moyermarine.com/index.htm
I have no axe to grind here, just a satisfied customer and E38 owner. By the way, if you call them, Don Moyer is very helpful and will spend as much time as you need answering questions.
