Yanmar 4JH4-HTE impeller change

Did a search but didn't find anything...

It's time for the annual impeller change on my Yanmar. My first change was done by a Yanmar tech but this time I'm going to tackle the job. I did a search on the net, and some folks recommend removing the entire seawater pump due to poor access to the impeller after removing the cover.. The front of the engine sits close to a bulkhead, so you basically have to do everything by feel. And the alternator is in the way.

I found a little Yanmar puller that some have used to successfully get the impeller out. Has anyone here had success with this thing?



This is what the pump looks like. Would be easy if I could get to the front of the engine!


The service manual says to remove the pump...

I've read that many folks have had lots of trouble getting the impeller out and also getting the O ring to seat once they get the new impeller in due to the inability to see what you are doing. So I'm wondering if I should just remove the entire pump. It looks like four bolts to get the pump off, but then I wonder about creating an oil leak or causing some other problem.

Ideas? Anyone done this by feel before?

We have a Yanmar 4JH2-UTE where the impeller cover faces the other way, but things are tight and mostly done by feel as well.

I went with a Speedseal cover, which simplifies things a whole bunch. There are oversized knurled bolts so tools aren't needed, and the o-ring sits in a machined groove in the cover itself. The bottom two knurled bolts always stay in place on the water pump, and the impeller cover just slides into place...eazy-peazy!!!!!

Of course, this does nothing to simplify getting the old impeller out...

This is the one I used;

Welcome to Speedseal

and this one is better but wouldn't fit the 4JH2;

Welcome to Speedseal Safety Covers

Don't know if this helps...good luck!

MurrayM said:

We have a Yanmar 4JH2-UTE where the impeller cover faces the other way, but things are tight and mostly done by feel as well.

I went with a Speedseal cover, which simplifies things a whole bunch. There are oversized knurled bolts so tools aren't needed, and the o-ring sits in a machined groove in the cover itself. The bottom two knurled bolts always stay in place on the water pump, and the impeller cover just slides into place...eazy-peazy!!!!!

Of course, this does nothing to simplify getting the old impeller out...

This is the one I used;

Welcome to Speedseal

and this one is better but wouldn't fit the 4JH2;

Welcome to Speedseal Safety Covers

Don't know if this helps...good luck!

Click to expand...

Awesome. Thanks.

I assume getting the O ring seated properly is a big source of people's frustration, so I will look into this for sure.

So you never considered removing the entire pump like the service manual recommends?

cardude01 said:

So you never considered removing the entire pump like the service manual recommends?

Click to expand...

Not sure if that's what mine recommends...will check after work.

Plus 1 on Speedseal cover. Makes the job much easier.

This is the tool I use on my 4JH3E (rearward facing pump - have to work blind because you can't remove the pump without removing the engine mount!)



Link: IMPELLER PULLER

That looks like a great idea. But I think I would get a couple extra of those thumbscrews, just in case.

LarryM said:

Plus 1 on Speedseal cover. Makes the job much easier.

This is the tool I use on my 4JH3E (rearward facing pump - have to work blind because you can't remove the pump without removing the engine mount!)

Link: IMPELLER PULLER

Click to expand...

I don't think I could get that big puller in place the way my pump faces forward.

Do the impellers have threads? I've heard some people pulling them with this thing:

The impeller on mine doesnt uave threads, but I've got plenty of room to pull from the front with numerous tools. I also have pulled my pump before and from what I recall of your Island Packett intallation (I also talked to the guy that did the installation), I'd pull the pump and see exactly what you've got there....and how hard a pull it is so you know what and how to try next time and what tool you may be able to make, modify or buy. Whatever you do, don't blindly pry or damage your unit trying simething desperate.

Cardude,

I have the same engine in my sailboat. Fortunately for me, I have easy access to the front of the engine so changing the impeller is so simple that even I can do it. However, on the earlier engines, the water pump was in a different location and owners of earlier Catalina 400s have cursed Yanmar every time they change the impeller.

Two things they have done to make the job easier. The first is to use the Speedseal cover as was already recommended. It makes it a much easier job. The second thing they have done is to cut a hole in the boat. Many have cut through the cabin wall that is on that side of the engine and installed an inspection door so they can look directly at the water pump. This may not be possible for your boat.

The impeller change can be done by feel, if you have a Speedseal cover. It is hard, but my fellow Catalina 400 owners make it work. They will normally use a screw type puller like was shown earlier. It is relatively easy to screw in, then turn with a wrench even if you can't see what you are doing. They also use a product such as Super Lube on the O-ring when they install it. The Super Lube allows the O-ring to stick into the groove but you do have to carefully feel around it to make sure it is seated all the way around. Finally, some type of inspection mirror, or even cheap inspection camera will help.

Personally, I would NOT try taking off the water pump to change the impeller. I think that would end up being more work, and open you up to more possible problems then trying to change the impeller blind. If your O-ring isn't seated properly, you will spot that as soon as you start up the engine and check for leaks. If so, then just take off the Speedseal cover and try again.

cardude01 said:

So you never considered removing the entire pump like the service manual recommends?

Click to expand...

Checked the service manual for our 4JH2 and there is no recommendation to remove the whole pump to change the impeller for regular replacing of the impeller. In the operation manual (periodic checks and maintenance chart) it says simply to change the impeller every 600 hours.

The service manual does describe how to remove the impeller during a servicing or rebuild of the sea water pump...I'm pretty sure they don't mean the whole pump has to come off every 600 hours.

I have 4LHA-STP in my boat. The impeller cover is on the rear of the water pump and there really isn't room to get the impeller out, no matter what tool you use so I always pull the pump. It's WAY easier. And access on my port side motor is pretty darn limited. No worries about an oil seal. It's four bolts and two hoses. Piece of cake.

Pulling the impeller is easy with the pump on the bench.

FWIW I tried a speedseal, I know a lot of people swear by them but mine leaked like crazy.

Pull the pump. You won't regret it.

You are over thinking the process. First of all get some pure silicone gel from a dive shop. This is used to lubricate the impeller and to keep the new O ring in place. ALWAYS buy a Yanmar replacement impeller. Others, with the same part number, will not last even 250 hours.
Close the sea cock.
Remove the impeller cover.
Remove the cover O ring.
Take a tooth pick and clean out the O ring grove.
Pull the impeller using channel lock pliers.
Grease up the new impeller fins and center hub and while bending the fins down on the narrow side of the pump, next to the intake hole, push the new impeller into place.
The gear shaft has no key so any place on the shaft works.
Direction of the fins to install the impeller does not matter since they will assume the correct position once you start the engine after you are done.
Grease up the cover O ring and "Stick" in place.
Install the cover slowly tightening the four screws evenly.
Open sea cock
Run engine
Check for leaks.

Pgitug said:

You are over thinking the process. First of all get some pure silicone gel from a dive shop. This is used to lubricate the impeller and to keep the new O ring in place. ALWAYS buy a Yanmar replacement impeller. Others, with the same part number, will not last even 250 hours.
Close the sea cock.
Remove the impeller cover.
Remove the cover O ring.
Take a tooth pick and clean out the O ring grove.
Pull the impeller using channel lock pliers.
Grease up the new impeller fins and center hub and while bending the fins down on the narrow side of the pump, next to the intake hole, push the new impeller into place.
The gear shaft has no key so any place on the shaft works.
Direction of the fins to install the impeller does not matter since they will assume the correct position once you start the engine after you are done.
Grease up the cover O ring and "Stick" in place.
Install the cover slowly tightening the four screws evenly.
Open sea cock
Run engine
Check for leaks.

Click to expand...

Thanks, but I don't think you are grasping how buried this pump location is. No way to get pliers in there. No way to see what's going on.

But I will definitely get a Yanmar impeller. Don't want to do this very often.

Dougcole said:

I have 4LHA-STP in my boat. The impeller cover is on the rear of the water pump and there really isn't room to get the impeller out, no matter what tool you use so I always pull the pump. It's WAY easier. And access on my port side motor is pretty darn limited. No worries about an oil seal. It's four bolts and two hoses. Piece of cake.

Pulling the impeller is easy with the pump on the bench.

FWIW I tried a speedseal, I know a lot of people swear by them but mine leaked like crazy.

Pull the pump. You won't regret it.

Click to expand...

Ok. Thanks. I will definitely pull the pump. Those bolts are relatively easy to get to.

Take my word for it.....I've seen Cardude's Yanmar. Even the skinny hulled catamarans are easier. But it is a good point about making holes for special access. Wasn't there somme access to the front of the engine under the companionway steps? Could that be enlarged?

I think all the new Yanmar impellers have threads. Some of my older spares don't. One more tip, use a zip tie to collapse the vanes and when it's about halfway in cut the zip tie off. Also you can use dishwashing soap for lube.
I wouldn't pull the pump unless I had to. Only you can make that call.

Rafe

healhustler said:

Take my word for it.....I've seen Cardude's Yanmar. Even the skinny hulled catamarans are easier. But it is a good point about making holes for special access. Wasn't there somme access to the front of the engine under the companionway steps? Could that be enlarged?

Click to expand...

Yeah there is access under the steps through a removable panel about 8x12". That's where I will get to it. See it? Hiding under the steps! ?



I was going to try to cut an access hole for front access but the AC unit is and some other stuff is in the way.

It's really not going to be that hard to remove the pump. I'm just being a little biatch.

Cat Daddy said:

I think all the new Yanmar impellers have threads. Some of my older spares don't. One more tip, use a zip tie to collapse the vanes and when it's about halfway in cut the zip tie off. Also you can use dishwashing soap for lube.

I wouldn't pull the pump unless I had to. Only you can make that call.



Rafe

Click to expand...

Zip tie, I never thought of that. Great tip.

Another advantage of pulling the pump is that you can actually see into the impeller chamber and inspect it (and the cam) for wear. I had to have both my pumps rebuilt a few months back, after only 550 hours the base plates were really worn and the seals were in bad shape. Rebuild was about $250.

Do I remember correctly that you had an overheat issue some months back? A belt failure maybe?

PgiTug definitely has the right idea on how to do it, but was missing the limited access part. Super Lube is a silicone grease that is wonderful for things like impellers or heads. Wonderful stuff.

I have tried the zip tie technique, and found that it was a bit more trouble than it was worth. However, I have ready access to the pump. For our OP, it might be a good option.

Dougcole said:

Another advantage of pulling the pump is that you can actually see into the impeller chamber and inspect it (and the cam) for wear. I had to have both my pumps rebuilt a few months back, after only 550 hours the base plates were really worn and the seals were in bad shape. Rebuild was about $250.

Do I remember correctly that you had an overheat issue some months back? A belt failure maybe?

Click to expand...

Yeah. Had a heating issue. Boiled out the heat exchanger with Barnacle Buster and that cleared it almost all up. Still climbs up a bit at WOT however after a few minutes. Also had a belt failure.

What are you thinking?

cardude01 said:

Yeah. Had a heating issue. Boiled out the heat exchanger with Barnacle Buster and that cleared it almost all up. Still climbs up a bit at WOT however after a few minutes. Also had a belt failure.

What are you thinking?

Click to expand...

Barnacle Buster is great for cleaning the raw water side, but the other problem is scaling on the antifreeze side of the coil. Use Napa diesel cooling system flush for this. Follow directions and all will be fine. Until you do, each season the WOT temp will rise sooner and higher..

Dude: I see your problem from the pic you posted earlier in this thread - talk about wallpapering your hallway through the letter box!


As others have suggested, remove the pump the first time around, then you will know what everything looks like if you do it in-situ the next time.

Take some digital pics if your memory is as bad as mine.

Greasing impellers makes assembly much easier, but petroleum-based grease, or the white lithium stuff, will soften them. Pure silicone grease is the stuff to use. A tube like this will last a long time.
http://www.amazon.com/gp/product/B0054DWS1W

A Jabsco impeller-puller is a good investment. They make two sizes - you would need the smaller one.

Post #11 in the link below describes a little device I made some years ago for compressing impeller vanes prior to installation. It has repaid me many times for the 10 minutes it took to make.
http://www.trawlerforum.com/forums/s6/stuck-impellers-3848.html

dhays said:

PgiTug definitely has the right idea on how to do it, but was missing the limited access part. Super Lube is a silicone grease that is wonderful for things like impellers or heads. Wonderful stuff.

I have tried the zip tie technique, and found that it was a bit more trouble than it was worth. However, I have ready access to the pump. For our OP, it might be a good option.

Click to expand...

This one is the silicone grease. Get the wrong grease and neoprene impellers will swell.
http://www.amazon.com/Super-Lube-92..._UL160_SR121,160_&refRID=1B2293KWGKE4G1H40HMH

Thanks everyone. I'm on it!

I have used the threaded impeller puller - works great. A socket/rachet is doable when working blind. I have to work my impellers with one hand, usually with my laying on top of the engine.

The problem I have with removing the pump is that you have to remove the hoses, and still be able to tighten the hose clamps, and pump bolts. How did the tech do it?

Some of my impellers have come with little packets of glycerin which has really helped.

sdowney717 said:

This one is the silicone grease. Get the wrong grease and neoprene impellers will swell.
http://www.amazon.com/Super-Lube-92..._UL160_SR121,160_&refRID=1B2293KWGKE4G1H40HMH

Click to expand...

I could be wrong, but I thought that the original Super Lube is OK for use on neoprene, at least according to the manufacturer. I have been known to be mistaken in the past. However, I have used Super Lube on the impellers on my Yanmar 4JH4 since I have owned it (about 5 impeller changes so far).

dhays said:

I could be wrong, but I thought that the original Super Lube is OK for use on neoprene, at least according to the manufacturer. I have been known to be mistaken in the past. However, I have used Super Lube on the impellers on my Yanmar 4JH4 since I have owned it (about 5 impeller changes so far).

Click to expand...

My engine manual mentions it regarding neoprene, no petroleum products.
I seem to recall Jabsco saying that too. I have Jabsco pumps, but thinking of switching to Globe impellers.
Nitrile rubber is not a problem.

And I was reading some reviews on Amazon's site where a buyer complained the rubber he used it one was wrecked, and another poster said to only use the silicone version since the other one had petroleum products.

So I just wont take that risk, especially when the other one is certainly not going to be causing a problem for sure.

Update:

Got the impeller changed today. As usual, I was making a bigger deal than it was. I did buy the little $21 Yanmar impeller puller and that made it easy to get out (I went back with a Yanmar impeller that has the threads built into it for the puller). It was actually harder to get the impeller back in due to the stupid location, and the hardest thing of all was finding the bolt holes bling and trying to grab the tiny 8mm bolts with my big clumsy fingers.

The puller came with some glycerine for lube. It said on the package do not use any petroleum based lube.

I would not want to do that out in rough water however. If I spring for the Speedseal kit it would make it easier to get the little cover plate back on I think-- the bolts in the kit have big knurled heads on them I think and the seal stays put in the cover? Is that right?

cardude01 said:

I would not want to do that out in rough water however. If I spring for the Speedseal kit it would make it easier to get the little cover plate back on I think-- the bolts in the kit have big knurled heads on them I think and the seal stays put in the cover? Is that right?

Click to expand...

Not sure about the seal staying put on the cover, but the screws would be a lot easier to put in.

Glad it worked out for you.