Yanmar genny engine

[cardude01]

I was changing the oil on the genny and after starting it to check for oil leaks I noticed a drip from the impeller housing. Took the plate off and checked the impeller and resealed it.

Still leaks.

Noticed a little screw at the base of the impeller housing. Looks like coming from there but could be coming from shaft also maybe?

What's that screw for? Anyone ever had a leak like this


Looks like salt on the shaft.


The little screw.

Edit:

Cleaned it off and looked again. Definitely coming from the shaft that spins the impeller. Is there a reparable seal on that shaft?

 

[N4712]

I'd replace pump and rebuild old for spare.

 

[LarryM]

I was changing the oil on the genny and after starting it to check for oil leaks I noticed a drip from the impeller housing. Took the plate off and checked the impeller and resealed it.

Still leaks.

Noticed a little screw at the base of the impeller housing. Looks like coming from there but could be coming from shaft also maybe?

What's that screw for? Anyone ever had a leak like this

View attachment 43119
Looks like salt on the shaft.

View attachment 43120
The little screw.

Edit:

Cleaned it off and looked again. Definitely coming from the shaft that spins the impeller. Is there a reparable seal on that shaft?

The little screw secures the cam inside the pump cavity.

If a Yanmar engine, it will probably have a Johnson pump installed. The seals can typically be changed and are available individually, or in a pump rebuild kit. You may need a gear and bearing puller to disassemble it, and possibly a press to reassemble, depending on the model.

Believe it or not, the shaft seals on the raw water side have been known to leak when the pump runs after a period of disuse, and re-seal after running for a while. I have seen this on two different Yanmar diesels. Since you have it back together, run it a while and see what happens. If it fails, it will likely fail slowly so it can't hurt to run it a bit and see.

 

[cardude01]

The little screw secures the cam inside the pump cavity.

If a Yanmar engine, it will probably have a Johnson pump installed. The seals can typically be changed and are available individually, or in a pump rebuild kit. You may need a gear and bearing puller to disassemble it, and possibly a press to reassemble, depending on the model.

Believe it or not, the shaft seals on the raw water side have been known to leak when the pump runs after a period of disuse, and re-seal after running for a while. I have seen this on two different Yanmar diesels. Since you have it back together, run it a while and see what happens. If it fails, it will likely fail slowly so it can't hurt to run it a bit and see.

Ok. Will run it awhile and see if it seals. That would be nice.

 

[TDunn]

It is easy to buy and install new seals. The only tools you need are a few blocks of wood and a hammer. It is about a 15 minute job.

 

[cardude01]

It is easy to buy and install new seals. The only tools you need are a few blocks of wood and a hammer. It is about a 15 minute job.

Awesome. Thanks.

I'm having a hard time finding a good source for Yanmar parts. Who do y'all use?

 

[LarryM]

Cardude,

Actually, here is a pretty good overview of what it will take to overhaul the Johnson pump. Compass Marine did a good job on this and it clearly shows what it will take.

Sources for the pump parts are the generator manufacturer, Yanmar if you can positively identify the engine type, Depco Pump Company, or just get online with the pump model number and see what sources you can find.

Here are some Yanmar parts sources if you are back on the Gulf Coast:

Laboarde Products, Channelview TX, 281-247-8925
Gulf Complete Marine Service, Inc., Kemah, TX 281-334-4417
Y.E.S., Kemah, TX 281-538-9377
Palmer Power, Houston, TX 800-364-4637

I do like the idea of buying a new one and having a rebuilt as a spare. That's what I do for my main, and might do it for the generator next time it needs service.

 

[cardude01]

Wow. Thanks Larry. You are the Yanmar guru.

 

[Baker]

Cardude,

Actually, here is a pretty good overview of what it will take to overhaul the Johnson pump. Compass Marine did a good job on this and it clearly shows what it will take.

Sources for the pump parts are the generator manufacturer, Yanmar if you can positively identify the engine type, Depco Pump Company, or just get online with the pump model number and see what sources you can find.

Here are some Yanmar parts sources if you are back on the Gulf Coast:

Laboarde Products, Channelview TX, 281-247-8925
Gulf Complete Marine Service, Inc., Kemah, TX 281-334-4417
Y.E.S., Kemah, TX 281-538-9377
Palmer Power, Houston, TX 800-364-4637

I do like the idea of buying a new one and having a rebuilt as a spare. That's what I do for my main, and might do it for the generator next time it needs service.

I am pretty sure Laboarde is a wholesale distributor.

Gulf Coast Complete....I am not a fan.

YES is the best of the bunch...Talk to Cyndi

Don't know Palmer.

What kind of generator???...Kohler? Land and Sea is a Kohler and Yanmar dealer....talk to Brandy. They do good business.

 

[cardude01]

It's a Maspower generator with a Yanmar 3TNV76 engine.

Thanks for the info!

 

[FF]

"If it fails, it will likely fail slowly so it can't hurt to run it a bit and see."

The pump pressurizes the water to move it.

The area behind the pump that drives it is not under pressure.

Why would the seal failure not pump water into the engine block?

Is there a second oil seal in the block?

 

[sunchaser]

Dude

There is no upside to waiting for the pump to fail, which it will. Weep holes are there for a reason, to weep before you do. As suggested by some very bright people already on this thread, get a new pump. Then you can play around with hammering on your old one.

As you continue bringing your vessel back into reliable shape do each task correctly and conservatively. You will not regret it

 

[Rogerh]

I cant say enough for Depco pump. They will fix your pump and get it back to you quick and reasonable. They will give you a cost estimate on the phone before you send it to them. Best service I have ever had.
Agree that you should buy a new pump and rebuild or get this one rebuilt. Having a backup on trips is worth alot.

 

[cardude01]

I'm tired of weeping. I like the new pump idea as well.

Now to figure out what pump I have. It looks like a Johnson pump from some pics I've matched up on the internet. I didn't see any numbers on my pump, but it was still installed on the genny and hard to see.



Thanks!

 

[LarryM]

"If it fails, it will likely fail slowly so it can't hurt to run it a bit and see."

The pump pressurizes the water to move it.

The area behind the pump that drives it is not under pressure.

Why would the seal failure not pump water into the engine block?

Is there a second oil seal in the block?

Fred,

Yes, there are two seals, one on the water side and the other on the crankcase side. The weep hole is between them so that if either leaks, it is directed out of the pump housing and does not cross from one side to the other. It also provides a visual indication of which seal is leaking.
All in all a pretty good design.

 

[cardude01]

Found the pump finally. It is a Jabsco pump. $350. Sigh.

Sent the pic to Pumpvendors so they could try to match it up, and the guy emailed me back in 5 minutes. Said he got the number off the front plate that I emailed him. I totally missed the part number stamped on the plate. I'm blind.

 

[LarryM]

Found the pump finally. It is a Jabsco pump. $350. Sigh.

Sent the pic to Pumpvendors so they could try to match it up, and the guy emailed me back in 5 minutes. Said he got the number off the front plate that I emailed him. I totally missed the part number stamped on the plate. I'm blind.

If this is the pump, it looks like they also sell the Major and Minor Service Kits at reasonable prices. You might ask them if you haven't already. That way, you could rebuild your old one for a spare for not too many $$$.

In case you didn't already know, according to Mastry Marine's dealer locator, the nearest authorized MasPower dealer is:

TEMPEST MARINE SERVICES Inc.
824 CR 792
Oyster Creek, TX 77541
Phone: 979-233-0700
email: tempestmarine@hotmail.com
Website: www.tempestmarineservices.com

Have fun

 

[CW]

I had Depco rebuild my seawater pump for my Northern Lights genny last year. I also had excellent, quick service with a good turn around time. Good luck.

 

[cardude01]

My plan is to get a new pump then try to rebuild the other one and use it as a spare.

 

[ranger58sb]

If a Yanmar engine, it will probably have a Johnson pump installed. The seals can typically be changed and are available individually, or in a pump rebuild kit. You may need a gear and bearing puller to disassemble it, and possibly a press to reassemble, depending on the model.

Found the pump finally. It is a Jabsco pump. $350. Sigh.

Sent the pic to Pumpvendors so they could try to match it up, and the guy emailed me back in 5 minutes. Said he got the number off the front plate that I emailed him. I totally missed the part number stamped on the plate. I'm blind.

I was just about to say our Kohler genset has a Yanmar 3TNE diesel and the pump is a Sherwood. With code stamped on the plate. And it uses SAE fasteners. (Which I didn't expect, until I figured out the pump was a Sherwood.)

Anyway... good you tracked yours down. Blind or not.

-Chris

 

[FF]

"My plan is to get a new pump then try to rebuild the other one and use it as a spare."

NO!

After you rebuild the old pump, install it. See it back working!

The new one gets put in the locker as the on board spare.

 

[Larry M]

...After you rebuild the old pump, install it. See it back working!

The new one gets put in the locker as the on board spare.

Great advice! We try to do that now even with new spares. Through the years we've been burned a few times thinking the spare was an exact replacement or the rebuild was rebuilt correctly.

 

[cardude01]

Ahh. Gotcha. Make sure it works.