Impeller change

[cardude01]

Have a 4jh Yanmar.

I replaced the impeller after my trip from Florida to Texas, but have only put about 100 hours on it since here in over a year. Manual says every 250 hours or every year, which ever comes first.

Does everyone replace the impeller every year?

 

[O C Diver]

I think it's a good practice. You really haven't hated life until you try to change one on a rocking boat, in a miserably hot engine room, while simultaneously trying to avoid busting your knuckles and not burn yourself. I usually pull the pump off and check the the bearings etc. in the process. Seems like cheap easy peace of mind when you're doing it on your schedule at the dock.

Ted

 

[cardude01]

Yeah. And mine is a bitch to get to so your idea makes even more sense.

Dammit!

 

[North Baltic sea]

Have a 4jh Yanmar.

I replaced the impeller after my trip from Florida to Texas, but have only put about 100 hours on it since here in over a year. Manual says every 250 hours or every year, which ever comes first.

Does everyone replace the impeller every year?

I take it off every winter season and I check whether the cracks, if not put into place until the spring of old and period of the season. I have never yet been broken up about. 200-250 hours a season, or a total of 400-500 hours earlier, this was my boat volvo twins. I can not say the quality seaboard seamax impeller my tug, experience in just a few months.

Of course, I have included a new imeller and seals, and a good puller, quick work.

 

[Drake]

I change impellers every year. I agree that it's the cheapest insurance you can get against a major PIA.

 

[Pack Mule]

Whatever you do take your time and be careful .
I did this early Sunday morning while working on our hot water heater . It was one of those hoses that seems to marry the fitting . I was trying to slit the hose after I took the clamp off . Dumb mistake . I was tied to the dock with some nice music on the stereo , everything was peachy . Ted is right , do it now .

 

[psneeld]

I change mine even year, but my 6 month cruise plus puts about 500 hours on it.

The less you use the engine, it is almost as hard on the Impeller so every year is good unless you lay up the engine and take the impeller out and let it straighten it's blades.

 

[cardude01]

Whatever you do take your time and be careful .

I did this early Sunday morning while working on our hot water heater . It was one of those hoses that seems to marry the fitting . I was trying to slit the hose after I took the clamp off . Dumb mistake . I was tied to the dock with some nice music on the stereo , everything was peachy . Ted is right , do it now .

Dude. Crap. That looks terrible!

 

[twistedtree]

I think it's a good practice. You really haven't hated life until you try to change one on a rocking boat, in a miserably hot engine room, while simultaneously trying to avoid busting your knuckles and not burn yourself. I usually pull the pump off and check the the bearings etc. in the process. Seems like cheap easy peace of mind when you're doing it on your schedule at the dock.

Ted

 

[LarryM]

Have a 4jh Yanmar.

I replaced the impeller after my trip from Florida to Texas, but have only put about 100 hours on it since here in over a year. Manual says every 250 hours or every year, which ever comes first.

Does everyone replace the impeller every year?

On my Yanmar 4JH3E in Boomarang, I changed it every year, just to be on the safe side. In talking to those in the business though, I am led to believe that impeller life is much more a function of the water, specifically mud and silt, in which the boat is operated. Along the Gulf Coast, Galveston Bay, the ICW etc. with its typically muddy water, the silt content is high and the impellers can wear very quickly, as well as the pump covers, wear plates etc. in the pumps themselves.

The Yanmar JH3 Series Operation Manual states "Note: The impeller must be replaced periodically (every 1000 hrs.)."

The Yanmar 4JH3E Engine Service Handbook states that the Seawater Pump Durability, Impeller Flow Drop of 10% is 1500 hours minimum.

These numbers are way beyond my comfort level. I like seasonal much better.

 

[Captain Doug]

I replaced the impellers after a year on a new to me boat. After examining them I determined they were still good to use in an emergency and they became my spares. Next I replaced the impellers after 2 seasons and they were pretty cracked so now every year they get replaced and if still serviceable, they become emergency spares. Keep extra pump face screws and new gaskets in the spare kit.

 

[kchace]

I used to change impellers every other year. But after seeing the horrible set they get sitting for my 6 month winter layup and the pain in the butt it is to fish broken pieces out of the heat exchangers - I'd MUCH rather change impellers on my schedule and then not have to worry during the ensuing cruising season. After shopping around, I can get them for $25 each - very cheap insurance.

Ken

 

[SoWhat]

The risk of not changing a $20 part is chasing a bunch of little pieces of rubber through the system, usually to be found plugging the heat exchanger tubes. very very cheap insurance.

 

[twistedtree]

The thing with impellers is that if the hours don't wreck them, the time sitting idle will. And if they come apart, a simple replacement job quickly turns into a major hassle.

Prevention seems well worth it, at least that's what I'm telling myself as I gear up to change mine in a couple of weeks.....

 

[cardude01]

Y'all are killin me. Making me work!

 

[dhays]

On my sailboat I have a Yanmar 4JH4E engine. Only 56hp. I change the impeller every year. The impellers have never shown any sign of wear.

I am not sure what I will do on my Cummins QSB 5.9L 380hp engine. I changed the impeller right after I bought it last spring. The impeller had not been changed in a few years and it looked pristine. The impeller on my Yanmar is cheap. The impeller for the Cummins is not.

At this point, I am planning on inspecting the impeller after a year. The Cummins manual calls for inspecting the impeller at 250 hours or 6 months. Just opening up the pump and looking at it. It calls for removing the impeller at 500 hours or 1 year. Cleaning and inspecting the interior of the pump, inspecting the impeller but only replacing it if it is excessively worn.

Part of me says that if you are bothering to remove the thing, you might as well put a new one in. We will see.

 

[O C Diver]

I replaced the impellers after a year on a new to me boat. After examining them I determined they were still good to use in an emergency and they became my spares. Next I replaced the impellers after 2 seasons and they were pretty cracked so now every year they get replaced and if still serviceable, they become emergency spares. Keep extra pump face screws and new gaskets in the spare kit.

Doug,
You're new here, so I'm going to say this nicely, thow your f*cking used spare parts away! Buy new spares like belts, hoses, and impellers. When it's time to replace the item in service, use your spare and buy a new one for your spares. You're rotating out your spares, so what you have as a spare is unused and not that old. Think about it, if you have to change a failed impeller while out cruising with an old used spare, you'll just have to change it again later because it's old and used.

Welcome to the forum! Sorry for jumping on you. You just touched one of my biggest pet peeves.

Ted

 

[hmason]

On my sailboat I have a Yanmar 4JH4E engine. Only 56hp. I change the impeller every year. The impellers have never shown any sign of wear.

I am not sure what I will do on my Cummins QSB 5.9L 380hp engine. I changed the impeller right after I bought it last spring. The impeller had not been changed in a few years and it looked pristine. The impeller on my Yanmar is cheap. The impeller for the Cummins is not.

At this point, I am planning on inspecting the impeller after a year. The Cummins manual calls for inspecting the impeller at 250 hours or 6 months. Just opening up the pump and looking at it. It calls for removing the impeller at 500 hours or 1 year. Cleaning and inspecting the interior of the pump, inspecting the impeller but only replacing it if it is excessively worn.

Part of me says that if you are bothering to remove the thing, you might as well put a new one in. We will see.

I'm glad you said that. We travel from CT to FL and back to CT every Fall and Spring. I began changing impellers every trip but they always looked perfect. So, I began changing them after a round trip---still looked perfect. They had no "set" and none of the vanes showed any signs of cracking. I am getting ready to change them again next week. They've been in service for two years now. A quick inspection by removing the cover plate on the pump shows no "visible" wear but I will change them both. I have friends that haven't changed them in 5+ years. That's pushing it.

 

[dhays]

Doug,

You're new here, so I'm going to say this nicely, thow your f*cking used spare parts away! Buy new spares like belts, hoses, and impellers. When it's time to replace the item in service, use your spare and buy a new one for your spares. You're rotating out your spares, so what you have as a spare is unused and not that old. Think about it, if you have to change a failed impeller while out cruising with an old used spare, you'll just have to change it again later because it's old and used.



Welcome to the forum! Sorry for jumping on you. You just touched one of my biggest pet peeves.



Ted

I don't disagree with but...

I had a new spare impeller on the boat when I bought it. I pulled the old one and tried to install the new one. I couldn't. I thought I was just failing because the impeller was so much bigger than what I was used to with my little Yanmar.

I fashioned some DYI installer tools. They didn't work. I bought am impeller compression tool. It didn't work. I finally had a mechanic try and install it. He couldn't do it.

I finally bought another impeller. It went in slick as snot.

The spare impeller was in the manufactures own box. It had the correct part number stamped right on the impeller. Same part number as the one I successfully installed. However there was a very slight difference in the spines of the shaft that made it not fit.

In a seaway trying to change the impeller, do I want to trying to install one that has never been in that pump or one that I know fit because I had taken it out of that pump 6 months prior?

Just a thought...

 

[O C Diver]

I don't disagree with but...

I had a new spare impeller on the boat when I bought it. I pulled the old one and tried to install the new one. I couldn't. I thought I was just failing because the impeller was so much bigger than what I was used to with my little Yanmar.

I fashioned some DYI installer tools. They didn't work. I bought am impeller compression tool. It didn't work. I finally had a mechanic try and install it. He couldn't do it.

I finally bought another impeller. It went in slick as snot.

The spare impeller was in the manufactures own box. It had the correct part number stamped right on the impeller. Same part number as the one I successfully installed. However there was a very slight difference in the spines of the shaft that made it not fit.

In a seaway trying to change the impeller, do I want to trying to install one that has never been in that pump or one that I know fit because I had taken it out of that pump 6 months prior?

Just a thought...

Here's a thought: Save the one you just pulled out, to match it with the one you're buying for your spares. After you have confirmed that the new one is a match, throw the old one away.

Ted

 

[dhays]

I do as you suggest, on spares. When I am going to install a new item, such as an impeller or filter, I order a new one to go into the spares locker then use the new one that has been in the spares locker.

(If only I had a spares locker. I have a plastic tub with a lid that sits in the lazaret underneath the aft cockpit.)

 

[jleonard]

I change mine every other season. I use the spare then I buy a new spare. I don't save used impellers.

 

[Ski in NC]

Yanmar impellers seem to hold up well. If you change them once a year and they always look good, can probably go two years. Or more. Changed several that were at least five years old and they looked good.

Some Detroits with Jabsco's last very long. Changed several that were like ten years old and they looked great!! In fact, I can't remember ever changing a shredded impeller on a Detroit/Jabsco. Except for a few run with sea cocks closed.

My Cummins with Sherwood pump is an impeller eater. I only get about 250hrs before a zinc change reveals impeller blades. Fortunately the are easy to fish out. I don't change on schedule usually, but before any long trip. It fortunately has never failed to pump.

Wish Cummins would use Jabsco pumps...

 

[dhays]

Good to know Ski, I will keep an eye on that. As I said, when I pulled the impeller last year it looked great but I replaced it anyway since it was a number of years old.

 

[Comodave]

My port engine impeller is fairly easy to change once I modified the impeller puller. The original T handle would not make a revolution due to hitting the oil dipstick. I bought some all thread (metric of course) and put double nuts on it and use it instead of the T handle to drive the old impeller out of the housing. The starboard engine impeller is a living bugger to get to. I bought an aluminum insertion tool that should help, will be trying to replace the impeller in the next week or so. I also am going to install my new Speedseals on both pumps. These have knurled thumb screws that can be removed without any tools. The Speedseal covers use an O ring instead of a paper gasket so you don't have to clean off the old gasket from the face of the pump each time.

I am going to change the impellers each year since I don't want to have to change them in an emergency situation.

 

[cardude01]

I considered the Speedseal kit, but didn't pull the trigger for some reason. Any bad experiences with Speedseal?

 

[AusCan]

I've been tempted by the Speedseal kits as well. It certainly seems like it would help to reduce the number of bolts/washers/tools dropped into the bilge.


In regard to the lifespan of impellers... I would say this is inversely proportional to the length of time the engine has been run with the raw water seacock closed.

 

[Drake]

Doug,
You're new here, so I'm going to say this nicely, thow your f*cking used spare parts away! Buy new spares like belts, hoses, and impellers. When it's time to replace the item in service, use your spare and buy a new one for your spares. You're rotating out your spares, so what you have as a spare is unused and not that old. Think about it, if you have to change a failed impeller while out cruising with an old used spare, you'll just have to change it again later because it's old and used.

Welcome to the forum! Sorry for jumping on you. You just touched one of my biggest pet peeves.

Ted

GREAT advice. New spares is the cheapest insurance on the planet.

My $.02.

 

[Bigsfish]

Ted

Your smarter than you look. LOL. Great advice as usual.

 

[Larry M]

...In regard to the lifespan of impellers... I would say this is inversely proportional to the length of time the engine has been run with the raw water seacock closed.

Yup. Did that just a few weeks ago on the generator. Putting in the new impeller was the easy part. Chasing the pieces, that took the time.