I failed at impeller install

First time trying to change an impeller on a larger engine and I failed miserably.

Cummins QSB 5.9L with a Sherwood water pump. With great effort (and an impeller puller) I was able to get the old impeller out. However, I was not able to get the new in. I was able to get the vanes inside the housing and push the impeller in until it hit the shaft. I was not able to get the splines lined up on the shaft and push it all the way in. Unfortunately, the angle is a bit awkward and hard to get much leverage on he impeller to both twist and push at the same time. I finally had to give up in humiliation.

Open to any and all suggestions. If worse comes to worse, I have a mechanic coming out on Friday to reinstall my HX and after cooler. I am sure he can do it. But it is something that I need to figure out for the future.

How frustrating. Compress the vanes with a series of wire ties. Don't worry which way they compress they will fix themselves when the pump starts. Lube the impeller and shaft generously with grease of some sort; I use white lithium grease. As you push the impeller into the housing, cut each wire tie as it reaches the edge of the housing.

Hope this works for you. Good luck.

Thanks Howard. I did try a wire tie, but I will try multiple.

Everything Howard said and some patience.

if it still doesn't work, try putting the old impeller back in. if it goes in double check you have the right replacement.

It's a tough job, Dave. However I have been able to do it on the same engine so you know it is possible. Howard's advice is just what you need to do. I use at least 2 ties and compress the vanes so they have a smaller diameter than the pump and lube them well. I use SuperLube for this. It's still a struggle and I use a hammer to tap the impeller home. Make sure you have a small block of wood to protect the impeller.

You can get impellers that are threaded inside so you can use a bolt that you screw in the middle of the impeller which forces it out. I think the bolt is 3/4" but I'm not sure.
I believe this impeller is Sherwood 17000K, Fisheries sku# 86082. That's the one I recently bought for my Cummins 8.3.

If you have this impeller with the threads, you can buy a short bolt screwed into the impeller to protect it from the hammer technique.

Good Luck

Thanks Ron. I have an impeller puller that worked, but there is not a lot of room for it. A bolt might be easier.

The zip tie idea sounds good. I need to get some larger ties.

Did you try bumping the starter to get the spline to line up?

don't know if it would work in your situation but I used to have Perkins HT6-354 and it was much easier to remove the pump and replace the impeller sitting at the dinette with a coffee.

I came up with an idea the last time I changed the Cat impellers and it made the job of installing them much easier.


I cut the middle section out of an empty milk jug, making the section about 3" tall and the strip long enough to go all the way around the impeller and overlap an inch or two.


I wrap the section around the impellers then put the zip ties on the outside of the plastic strip. As I tighten the zip ties (I use 2 because of the height of the impeller) it forces the plastic strip to compress the vanes on the impeller. This works the same way as tightening the zip ties without the plastic strip, except the plastic strip makes the compression of the vanes much simpler.


I then apply some dish soap and start to slide the new impeller into the housing. AS the impeller goes in the plastic piece hits the end of the housing and it stays in place as the impeller slides out of it and into the housing.


Works like a charm.

That actually sounds like a pretty good idea. I may give that shot.


Lets see... Impeller is 3.5" in diameter, so the circumference would be 2*3.14*1.75=11". So 12" zip ties should do it.

dhays said:

That actually sounds like a pretty good idea. I may give that shot.


Lets see... Impeller is 3.5" in diameter, so the circumference would be 2*3.14*1.75=11". So 12" zip ties should do it.

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The first inch or so of a tie is smooth. You might want to pick up some longer ones.

hmason said:

As you push the impeller into the housing, cut each wire tie as it reaches the edge of the housing.

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dhays said:

Thanks Howard. I did try a wire tie, but I will try multiple.

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Try pre-compressing with hose clamps, each one tighter than need be. As you remove the inner-most clamps, subsequent clamps can (usually) compress the rascal enough to help you continue sliding it into place...

-Chris

I found that a piston ring compressor works wonders for getting large impellers installed.

OEM/Piston ring compressor 27039- Read1Reviews onOEM #27039

Be sure to get the full cuff style, not the smaller band that looks like an oil filter wrench.

Another good idea.

twistedtree said:

I found that a piston ring compressor works wonders for getting large impellers installed.

OEM/Piston ring compressor 27039- Read1Reviews onOEM #27039

Be sure to get the full cuff style, not the smaller band that looks like an oil filter wrench.

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Good advice. I finally broke down after years of frustration and bought this:Stanley Proto J2316 Proto Piston Ring Compressor - Hand Tool Sets - Amazon.com.

With a little grease, worked slicker than a weasel. Tighten the compressor down somewhat narrower than the opening and you have leeway inside the pump cavity to wiggle the impeller onto the splines.

Also, I replaced the hex head bolts on the impeller cover with SS socket head cap screws (I think that Flywright put me onto this). Helpful.

I use several hose clamps.

My piece of plastic works just the same way as the piston ring compressors, but mine was free, and not quite so fancy.

Phil Fill said:

I use several hose clamps.

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Have done the hose clamp routine. Major PITA. Especially where slippery lubricant is involved. Why use several clamps that you need to individually tighten/loosen when you can just use a piston ring compressor that tightens the impeller uniformly?

GFC said:

My piece of plastic works just the same way as the piston ring compressors, but mine was free, and not quite so fancy.

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That'll do it.

Best of luck. Not being an engine mechanic, I leave impeller replacement to him, Fortunately, I never boat very far from him.

I just pushem in while twisting in the appropriate direction. Soap is a must. Havent had a problem in years, everything from the little cummins impellors to the big double 16v92 impellors. I disable the start function and attatch my push button starter bump unit. Tap the impellor with a brass hammer while "bumping" the engine. I can change an impellor on my 8v92s in about 10 minutes. Practice helps.

Dave: We greatly appreciate you sharing your frustration just the way you did. Many of us here don't have mechanical genius, ability or even inclination. Time, practice, and a lot more frustrating moments are in your boating future, but all the while you will be getting to know your boat, and who knows, maybe even become friends!

Dave, I too thank you for your post, I had a similar impeller problem that a dock neighbor came over and bumped the starter on the engine while I taped it the rest of the way in.
Good luck!

How does one disable the ignition so the engine doesn't start when bumping it?

cardude01 said:

How does one disable the ignition so the engine doesn't start when bumping it?

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You just bump it. Dont hold the start button long enough to start the engine.

Boatdiesel has a great 'how to' section for impeller installation for the 5.9. Worth the price of membership alone.

cardude01 said:

How does one disable the ignition so the engine doesn't start when bumping it?

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Good question. Especially since there really isn't an "ignition system" on a diesel.

Depending on the brand and model diesel you have to keep it from getting fuel. In many cases just leaving the start breaker or switch off will do that. On GBs I just use to hold the stop button in while rolling the engine over if I didn't have a remote start button with me.

Or you can use a wire tie or something else to hold a fuel solenoid in the no flow position.

Capt.Bill11 said:

Good question. Especially since there really isn't an "ignition system" on a diesel.

Depending on the brand and model diesel you have to keep it from getting fuel. In many cases just leaving the start breaker or switch off will do that. On GBs I just use to hold the stop button in while rolling the engine over if I didn't have a remote start button with me.

Or you can use a wire tie or something else to hold a fuel solenoid in the no flow position.

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I didnt bother with that. I just hit the starter for a split second. Just long enough to get power to the starter for a millisecond (i did not time it) and it didnt start.

In fact i did it several times without ant issues to get the old broken one out.

bligh said:

I didnt bother with that. I just hit the starter for a split second. Just long enough to get power to the starter for a millisecond (i did not time it) and it didnt start.

In fact i did it several times without ant issues to get the old broken one out.

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Depends on the diesel and depends on the day. I've gotten away with it plenty of times.

But I've also seen them fire off with not much more than a bump.

Impeller

Dave: I have the QSB 5.9 380 in our AT-34 and have replaced the impeller a few times. On our engine I use silicon grease on the inside of the housing, then twist and push the impeller in until it lines up with the splines, then I use a long screw driver and it levers right in (end of screw driver lines up with a protrusion on the block and then pushs against the impeller with shank of driver). Your engine should be similar. Hope this helps.

dhays said:

First time trying to change an impeller on a larger engine and I failed miserably.

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Good that you're changing out. Ask me how I know.