Pauli, there is a small "weep" hole behind the rear seal in most engine water pumps. This is to indicate when the rear seal starts leaking so the pump can be replaced before the seal completely fails. Three reasons for pump failure are age, too much belt tension, and poor quality coolant. Hope this helps, I don't know the part # or the Kubota #.

Paul, I got to thinking (sometimes I do that) about if your talking about your coolant pump or raw water pump. I was refering to the coolant pump. I believe the seal for the rear of the raw water pump is replacable, maybe the coolant pump has a replacable seal as well. Look at the parts manual for your engine, I'm going to look at mine because if the seal is available I'll order one as a spare! GOOD LUCK :o

The raw water pump bearings on our 1999 boat failed at about 1700 hours and it was not pretty. Fortunately, I could sail back to the dock - sort of.

deising,
1700 hours is a HUGE number of hours for a raw water pump. I sail in fairly clean water (not much suspended sand, etc.), and expect to replace the raw water pump seals about every 500 hours, along with the carbon bearing. The impeller gets replaced every other year (~200 hours). Mine is a M25XP with an Oberdorfer pump, and yours is a Sherwood, but I would think the life spans are similar. At the first sign of leakage from the raw water pump, replace the seals!

You are quite right, Tom. This is our first boat (acquired at the age of 46) so there were many things I am learning about boat maintenance.

Paul,
I don't know which water pump you have. I know just a little about the Sherwood pump, but I know the Oberdorfer pump intimately (the Admiral says too intimately!). The Oberdorfer pump has an inner and an outer lip seal, along with a carbon bearing. As mentioned above, I replace the lip seals every 500 hours or so. The carbon bearing lasts a little longer. I'm not sure what "repair kit" you are talking about. I normally order specific parts from Depco Pumps ([url]www.depcopump.com[/url]). There are other sources listed in the Owner's Encyclopedia. There is also an excellent article on rebuilding the Oberdorfer pump in the May 2008 issue of Mainsheet by Chooch Jewell. Hope this helps.

Try checking the bolts that hold the pump in place.. I had one that was stripped a bit and I discovered it was not really cinched down properly. No problem after replacing the bolts.

Chuck Parker

You are right! We found a little heap of salt building up underneath the raw water pump, I could not figure where it was coming from. 50 hours engine time later it became apparent the bearing was shot (we were in Tonga at the time) and there was a lot of dripping going on by the time we arrived back in New Zealand. I had an ordinary diesel mechanic help replace them, they were a common stock part.
BTW, I was told this hole is to release pressure so the water would not run past the seal into the motor, which would cause much damage.

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