Raw water intake pump questions

[Dr. D]

My raw water intake pump began leaking from the backside last week and I had it replaced. The tech who did the work gave me the old one and said the kit to replace the seals is $150.

Is having the seals fail after seven years expected?

Is replacing the seals on the old one worthwhile?

I remove the impeller with pliers. Could that have contributed to the failure?

 

[Don S/V ILLusion]

Is having the seals fail after seven years expected?

depends entirely on use, not the calendar.

Is replacing the seals on the old one worthwhile?

if you want to have a spare in an emergency, yes.

I remove the impeller with pliers. Could that have contributed to the failure?

Probably not. That’s how most people remove it wirhout harm

 

[Dr. D]

Don: Right, I should have included the motor has about 500 hours.

 

[JoeWhite]

Dr. D., what type of engine and pump. On Universal engine, I use Oberdorfer N202M-16 and yes the seals can be replaced and the kit is less than $100.00 including shipping.
Visit my website for complete content and view the album. And yes 500 hours is when it might start to leak.
What happens is the fine dirt particles in the water are like sand paper. These particles wear out the rubber seals causing it to leak.

Oberdorfer Seals Replacement | Sail La Vie

mei1970.org

 

[Stu Jackson]

My raw water intake pump began leaking from the backside last week and I had it replaced. The tech who did the work gave me the old one and said the kit to replace the seals is $150.

Is having the seals fail after seven years expected?

Is replacing the seals on the old one worthwhile?

I remove the impeller with pliers. Could that have contributed to the failure?

Joe's article is good. Here's another view with photos:
Oberdorfer Pump Rebuild 101 - Mysteries of the Oberdorfer - Seal Replacement - REBUILDING A PUMP w/Flix

7 years - normal
Worthwhile: of course, the seals are cheap, pump bodies are not
Impeller - nope

I suggest you learn more about how your pump is built and how the parts work together. The seals keep the oil in and the water out, never the two should mix.

Good luck. I was once in your shoes, read my link to find out what I learned and how.

 

[BigEasy]

Replaced mine on a Yanmar 3ym30 Johnson raw water pump (not engine coolant pump)at approximately 300 hours. Simple to replace; didn’t require removal of pump. Lip seal only w/o kit was $50 at Yanmar dealer. Definitely worth the cost of rebuilding and no, I do not believe that changing the impeller affected it. Simple to change; easy as changing impeller (almost)!

 

[Dr. D]

The motor is a Yanmar 3YM30AE and the pump is by Johnson F4B-903.

I found a video of rebuilding this exact pump. No way that can be done without removing the pump, BigEasy. Are we talking about the same part?

 

[BigEasy]

The motor is a Yanmar 3YM30AE and the pump is by Johnson F4B-903.
I found a video of rebuilding this exact pump. No way that can be done without removing the pump, BigEasy. Are we talking about the same part?

Doc,
I didn’t actually rebuild the pump, just replaced the lip seal only. Removed the front cover plate, pulled the impeller, removed the lip seal by pushing from rear of pump housing and delivering the seal forward over the shaft. Installed new seal ensuring that it was fully seated, reinstalled impeller & coverplate Without removing the pump from engine. I saw a video on You Tube as to how to do this.

 

[Dr. D]

OK, now I understand your comment.