3jh5e impeller replacement

[Duluthwinger]

Hi,
I am going to replace the raw water impeller on my 3jh5e yanmar this spring. In reading the book on this engine it has a puller to take out the impeller.
I have seen YouTube videos that just used two pliers to remove the impeller. I don't know how long the impeller has been in the engine and was not sure if the splines have a tendency to corrode or if the impellers come out easily.
Do any of you out there use anti seize on the splines to help replacing the impeller?
Thanks,
Al

 

[Ralph Johnstone]

Haven't bothered on a Yanmar 2GM20F. Has always come out easily for inspection. Check you impellor for wear. The local say you must replace annually or you'll die a horrible death. Mine is pushing 8 years and I inspect every 2-3 years but still carry a spare.

 

[dlochner]

Two pliers will work, however you may damage the impeller. Not an issue if you are replacing the impeller.

Does the water pump face forward? On the 3JH2e the pump faces after and there is barely enough room to remove the impeller. It easier to remove the starter first and pull out the impeller.

 

[Terry Cox]

Do any of you out there use anti seize on the splines to help replacing the impeller?

No. Glycerin is the only lubricant used on the impeller vanes. Do not use any other lubricant, otherwise it will diminish the life of the vane material.

Different model engine, but the impeller on our engine looked new after more than twenty years and over a thousand hours of use. I wiggled ours out with needle nose pliers and kept it as a spare. Pretty easy access on our 4JH2-TE.

 

[artboas]

Two pliers will work, however you may damage the impeller. Not an issue if you are replacing the impeller.

Does the water pump face forward? On the 3JH2e the pump faces after and there is barely enough room to remove the impeller. It easier to remove the starter first and pull out the impeller.

I feel your pain
I have the 4Jh with aft facing pump. Had to pull the alternator & intercooler. Insane
Figured out a way to fix that problem, and now it’s 10 minutes to change the impeller. I don’t understand how Yanmar could have done that.

 

[jssailem]

was not sure if the splines have a tendency to corrode or if the impellers come out easily.

Impellers tend to be made of a flexible rubber compound, corrosion is not an issue. Wear, lack of flexibility, breaking apart are all failure modes.

Recommendation: engine’s water pump impeller needs to be serviced after every 100 hours of use or once per year.

 

[Duluthwinger]

Thanks for the replies
I was wondering about putting never seize on the drive shaft of the pump. the shaft that drives the pump on my engine is splined and the inside of the impeller is also splined so I was wondering if it was a good idea to put never seize on these mating parts just to make sure that they would slide off next time I replaced the impeller.
It does look from the operation manual that the pump is facing forward.

 

[dlochner]

I've never used an anti-seize lubricant on the impeller. It is important to not use a petroleum product as that can affect the impeller. In freshwater I would not be too concerned with corrosion.

 

[Terry Cox]

I was wondering about putting never seize on the drive shaft of the pump.

I would not use it on our boat's impeller splines.

 

[Gary Ryan]

Just did our last year. And, like others, the impeller housing faces away from you My back was blown out last year, so I hired a guy to come in. He was able to lean over the engine, remove the 4 plate screws and pull out the impeller with needle nose pliers. It's not a keyed impeller but spline. He installed the new one all good. Took him about 30 mins. Me...I would have been stuck on top of the motor with a frozen back. I will do it next time on my own though.

 

[Tally Ho]

Normally, a puller isn’t needed…but if it is seized on the shaft, be careful trying to remove it. You do NOT want to pry against the pump housing. They are soft metal and damage easily.

I had an impeller that pretty stuck on the shaft. I worked on it for an hour on the boat and could not get it off. I did ding the housing edge some…so decided to take the pump home, where I could work on it in my shop. Doused it in PB Blaster or something, carefully pulled with needle-nose pliers, wiggled it a lot and got it off.

Greg

 

[artboas]

Just did our last year. And, like others, the impeller housing faces away from you My back was blown out last year, so I hired a guy to come in. He was able to lean over the engine, remove the 4 plate screws and pull out the impeller with needle nose pliers. It's not a keyed impeller but spline. He installed the new one all good. Took him about 30 mins. Me...I would have been stuck on top of the motor with a frozen back. I will do it next time on my own though.

Might want to check out the modification on my post .

 

[dlochner]

I feel your pain
I have the 4Jh with aft facing pump. Had to pull the alternator & intercooler. Insane
Figured out a way to fix that problem, and now it’s 10 minutes to change the impeller. I don’t understand how Yanmar could have done that.

Might want to check out the modification on my post .

What modification?

 

[Ralph Johnstone]

As a further to my previous blurb, the real reason I get around to inspecting my pump impellor every 2-3 years is because the cheap, toilet paper gasket leaks sea water at microscopic rate and covers the edge of the pump with green corrosion. Time to clean up and replace the gasket. I have tried lightly coating the gasket with SuperLube in the hope of permeating the gasket and making it waterproof, it leaks. I tried leaving the gasket lightly smeared with Superlube in a plastic bag for a few weeks before installing, LEAKS. This time I'm going to lightly coat the gasket with a teflon sealant and see if that make a difference. Live in hope, die in despair .

I don't know if sea water penetrates through the edge of the gasket and eventually appears on the outside or it leaks between the gasket/pump body interface. It takes about a year before the first green traces show and they show evenly,360 degrees around the pump body.

Anybody tried anything that actually works on the gasket or is this just my OCD showing through ?

 

[Terry Cox]

Anybody tried anything that actually works on the gasket or is this just my OCD showing through ?

I've always installed the gasket as it comes out of the package and have never had a leak issue.

 

[Ralph Johnstone]

I've always installed the gasket as it comes out of the package and have never had a leak issue.

I trust yours is the same gasket that looks like it's made from toilet paper ? Then it must be your clean living because I've tried everything else but, with no success to show for it to date.

 

[Terry Cox]

I trust yours is the same gasket that looks like it's made from toilet paper

Yup. Tissue paper thin, but seems to do the job on both the main engine and generator. I use a razor blade to scrape both surfaces clean of any old gasket material before placing the new. I've never applied any kind of sealant/lubricant to either surfaces, either.

 

[Ralph Johnstone]

All right, all right, I concede it's your clean living that has kept them from leaking .

I use a razor blade to scrape both surfaces clean of any old gasket material before placing the new.

Exactly my procedure before suffering years of microscopic leakage 360° around the gasket.

 

[Terry Cox]

All right, all right, I concede it's your clean living that has kept them from leaking

One could only hope!

 

[AlexB]

puller tool - Google Shopping I got such tool and cut it, so it fits between wines. works very good, does not damage impeller and pump.