Water pump (sweet water) leaking on Perkings 4108

[pr2501]

How long can pump hold before leaking becomes to big?
How to rebuild the pump?

[Lepke]

Coolant or salt water pump?
Both can be rebuilt. I rebuild mine.

How long until it fails? 100 or so hours. But running until failure can ruin the chance of rebuilding.

[pr2501]

Coolant.

What does it need to rebuild one?

[Lepke]

The pulley gets removed with a puller, but can be pressed off with an arbor press. There's a clip on the pulley front that needs to be removed first (not there on new pumps). Then there's a clip the holds the shaft in position that comes off before the shaft is pressed out from the pulley side. It comes out seal, shaft and impeller as one unit. You press the bearing out after removing the bearing clip. Keep track of the part order. There's a spacer and water thrower. It needs to go back the way it came out.
There's 2 seals. A ceramic seal next to the impeller and a felt seal between the bearings and housing. The ceramic seal is the one leaking water. The felt seal is to keep the bearing grease in place.

You should be able to find a PDF of the service manual on line. boatdiesel.com is one place. I'd upload here but the file is too big for cruisers. As I remember the the shaft is a USA size. Any good bearing supply should be able to match the ones in the pump. The bearings will have a stamped in number. I use a Arbor Press for pressing on and off parts. Most auto parts stores have a bearing press. I have 5 diesels I take care of with 9 pumps. The first time I buy bearings and seals, I get spares so I'm ready for next time. I keep rebuilt spare pumps for the boat engines.
The bearings can be open or sealed. The pump originally had open ball bearings and part of the process was to pack grease in the bearings. But since there's no way to regrease the bearings once the pump is together, sealed bearings work fine, I've used both kinds. Replace the bearings. They're probably why the seal failed. Last time I did a coolant pump, the bearings and seal were under $15.

A new pump is about $80 at www.parts4engines.com

[Bill O]

Originally Posted by pr2501

Coolant.

What does it need to rebuild one?

Here's a link to the parts manual for your motor. On page 12 of the manual it shows the blow apart/parts list for your pump.


If you don't have presses or other tools available, then purchasing a new one may be the better way to go. I looked quickly and could find one the fit on a tractor (same pump) for $67.

[a64pilot]

Pumps are rarely rebuilt, and many aren’t rebuildable They are pressed together and often a spot weld on the impeller.
Almost always pumps are replaced, they are usually so inexpensive that if there is a labor rate it’s cheaper to replace.
They will usually drip for a long time before they fail, if your where you can’t get a replacement one, remove the fill cap that removes pressure and that will often stop or greatly reduce the leak.

[pr2501]

Thank you all for your answers.
Usualy I would take care of it. But now as I am moving the boat from south to north Italy I think that I will lose a good weathet window thaking care of rebuilding the pump. But with info which I got here maybe on the end I coild decide to risk some troubles and get into it. But on the other way I don't think that is not good to compromise the trip trying to spare 50$.