Jabsco Pump Leak Again

[BriRich]

Hi Folks

Our boat has a Nissan TD27 engine. We have a Jabsco 3890-9011 water pump">raw water pump. We had the first one rebuilt and bought a new spare. The rebuild started leaking so we put on the new pump and it shortly thereafter started leaking. Belt is properly tensioned and the pulley is aligned. From the Jabsco manual it says ball bearing pumps can spin at 5,000 rpm and we're not close to that as the crankshaft pulley and the pump pulley are close in size.

One thing that is noticeable is that our water volume going through the exhaust is huge compared to other boats. Maybe need a bigger pulley and slow the speed down?

Any ideas why the pumps keep leaking?

Many thanks

Brian

[FlyingCloud1937]

Where do they leak from??

Lloyd

Originally Posted by BriRich

Hi Folks

Our boat has a Nissan TD27 engine. We have a Jabsco 3890-9011 raw water pump. We had the first one rebuilt and bought a new spare. The rebuild started leaking so we put on the new pump and it shortly thereafter started leaking. Belt is properly tensioned and the pulley is aligned. From the Jabsco manual it says ball bearing pumps can spin at 5,000 rpm and we're not close to that as the crankshaft pulley and the pump pulley are close in size.

One thing that is noticeable is that our water volume going through the exhaust is huge compared to other boats. Maybe need a bigger pulley and slow the speed down?

Any ideas why the pumps keep leaking?

Many thanks

Brian

[BriRich]

Originally Posted by FlyingCloud1937

Where do they leak from??

Lloyd

From the bottom at the open slot of the pump body on the pulley side of the pump.

[colemj]

That is the lip seal leaking. Possible causes are running in silty, sandy water, improper installation (there is a spacer between the water and oil seal that needs to be in the correct orientation), or scoring of the pump shaft that doesn't allow a good seal. Possibly the pump body is corroded and the seal does not fit tight in it.

Mark

[BriRich]

Originally Posted by colemj

That is the lip seal leaking. Possible causes are running in silty, sandy water, improper installation (there is a spacer between the water and oil seal that needs to be in the correct orientation), or scoring of the pump shaft that doesn't allow a good seal. Possibly the pump body is corroded and the seal does not fit tight in it.

Mark

I have two pumps one rebuilt and one new and they both developed the same leak. We are in clear clean water with no silt or sand. Both pumps started leaking so with the new pump at least it is not the shaft being scored. With the high volume of water we are pumping the only thing I can think of is the pump is spinning too fast and blowing out the seal, too much pressure???