Impeller Install Issues Cummins Diesel QSB6.7

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Clemson101

Clemson101

Member
Joined
Nov 25, 2016
Messages
17
Location
US
Vessel Name
Loretta
Vessel Make
Fleming 55
It is shameful for me to admit I toasted my impeller due to not re-opening the fresh water engine intake seacock after systems check. Luckily (I thought) I had a spare onboard. After removing the old impeller, I attempted to install the new one. I applied some Dawn to the new impeller but could not get it to engage more than half way. After 3 hours of making various attempts to twist the new impeller and checking for obstructions or if there was a "key" notch (not one I could find), I finally had to call Boat US. Attached a picture of the impeller housing. Any tricks to getting the new one back on?

My vessel is a 2015 Beneteau ST 34 with a 425 Hp Cummins Diesel model QSB6.7.

IMG_9344.JPG
 
Clemson101 said:
It is shameful for me to admit I toasted my impeller due to not re-opening the fresh water engine intake seacock after systems check. Luckily (I thought) I had a spare onboard. After removing the old impeller, I attempted to install the new one. I applied some Dawn to the new impeller but could not get it to engage more than half way. After 3 hours of making various attempts to twist the new impeller and checking for obstructions or if there was a "key" notch (not one I could find), I finally had to call Boat US. Attached a picture of the impeller housing. Any tricks to getting the new one back on?

My vessel is a 2015 Beneteau ST 34 with a 425 Hp Cummins Diesel model QSB6.7.

View attachment 69016
Click to expand...

Mine is a bear if the vanes get caught up on the water inlet "grate" on the pump body. You have to keep the leading tips of them bent inward towards shaft to pass.
 
kev_rm said:
Mine is a bear if the vanes get caught up on the water inlet "grate" on the pump body. You have to keep the leading tips of them bent inward towards shaft to pass.
Click to expand...



Thanks - that's what I assumed was catching the impeller but wasn't certain.
 
Some Silicon grease on the impeller it'self makes a big difference and a little on the shaft for easier removal next time , quite a few impeller suppliers include a little tube of silicon or other grease with the impeller, Yes the larger impellers can be a real struggle to fit, just to note when bending the rubber impeller vanes to pass the cam, be sure you bend in the correct direction of rotation other wise even though they do normally flip around, you can damage them, once started in the housing I often use a little gentle force in the prudent use of a rubber hammer,

Also be careful with the type of grease used as some impellers dont like various petroleum products although it usually is gone with in a few hours,

Cheers Steve
 
Take belt off pump and rotate pulley while shoving impeller. Probably vanes getting caught on slots in cam. A little rotation usually gets it cleared.
 
I compress the vanes (in the right direction) and use a nylon wire tie to hold them compressed. I also use a rubber lubricant on the vanes. As I insert the impeller, the wire tie slides out of the way while still keeping the vanes compressed.
 
I had a real problem on my starboard engine due to the fact that you can't really even see it. I bought a tool that you slide the impeller into and then push the impeller and tool into the pump. Then hold the impeller in place and pull the tool out. Works great. It is an aluminum sleeve with a funnel on one end to slide the impeller into the tool. I forget the name of the company, but it has been posted on this forum before.
 
I think this is the impeller tool that you are talking about Dave...amazingly the link is to "Impeller Tool dot com". No relationship to the company. Found it when I had an impeller problem. Didn't buy one so not sure how good a product it is.

Impeller Installation Tool
 
That is what I bought. No relationship to company, just a great product. My stbd engine would be almost impossible to change without it. The mechanic that had been working on my boat for the PO of 15 years said they drew straws as to who had to change the impeller and loser had the job. He said they usually pulled the pump to change the impeller. That was also a big job. With this tool, I can change the impeller with the pump in place in about 20 minutes.
 
I spent several days and dozens of techniques trying to get my "spare" impeller on last year. I even had a mechanic try and he couldn't. It turns out the splines on the impeller didn't match. The impeller even had the exact same part number on it as the one that came off. I bought a new impeller and it slipped right on.

I have no idea how common this is but it might not hurt to try it with another impeller. You will need another spare anyway so it doesn't hurt to try.

I have a Cummins QSB5.9.
 
A section of .010 inch shim stock (or there about), cut about an inch longer than the depth of the pump will also work in place of the tool. If lubed up it will pull out easily after inserting the impeller. I have used this many times.
 
I've used a piston ring compressor tool to compress the vanes of the impeller but the funnel looking tool looks far easier to use.
 
I also bought Speedseal cover plates for my pumps. They use an O ring instead of a gasket to seal the cover. I had an issue with them leaking at launch this spring. I had tightened the thumb screws as tight as I could, but they still leaked. Used a pair of pliers to tighten them some more and the leaks went away. Of course my fingers don't torque as well as they used to...
 
It doesn't matter which way the vanes bend on insertion, they will immediately come into position when the motor turns over, aided by the liberal application of grease you used to help slide the thing in.
Any grease will do, and a few zip ties are handy to compress the vanes, you can snip them off as it goes in.
 
Hi
is the new impeller a generic one or one distributed by the pump manufacturer,
This can some times make a small difference
regards
Liam
 
It was a Sherwood. And the mechanic that ended up doing the job used the same brand but had an additional installer tool somewhat like was described on this forum that made the install easy.
 
Comodave said:
I bought a tool that you slide the impeller into and then push the impeller and tool into the pump. Then hold the impeller in place and pull the tool out. Works great. It is an aluminum sleeve with a funnel on one end to slide the impeller into the tool. I forget the name of the company, but it has been posted on this forum before.
Click to expand...

firstbase said:
I think this is the impeller tool that you are talking about Dave...amazingly the link is to "Impeller Tool dot com". No relationship to the company. Found it when I had an impeller problem. Didn't buy one so not sure how good a product it is.

Impeller Installation Tool
Click to expand...

Comodave said:
That is what I bought. No relationship to company, just a great product. My stbd engine would be almost impossible to change without it. ... With this tool, I can change the impeller with the pump in place in about 20 minutes.
Click to expand...


Good to hear favorable reports. I bought one AFTER the last time I changed our starboard (inboard -- the easy one) impeller, but haven't used it yet.

Prior to the next change, I've had the yard change our port impeller, 'cause I can't get there from here. I'm hoping to be able to use the tool on the port engine, with me upside down and blind, next time.

And if it also helps me change the starboard impeller more easily -- the one I can actually see while working -- so much the better.

-Chris
 
Another vote for the impeller installation tool :thumb:

It takes all of the pain out of changing impellers on Cummins/Sherwood pumps, and many others I'm sure. Andy, the owner is a pleasure to deal with.

Here is where to get it.

ImpellerTool.com
Andrew Pecherzewski
(310) 780-8543
andypz26@gmail.com
 
CaptSteve53 said:
Some Silicon grease on the impeller it'self makes a big difference and a little on the shaft for easier removal next time , quite a few impeller suppliers include a little tube of silicon or other grease with the impeller, Yes the larger impellers can be a real struggle to fit, just to note when bending the rubber impeller vanes to pass the cam, be sure you bend in the correct direction of rotation other wise even though they do normally flip around, you can damage them, once started in the housing I often use a little gentle force in the prudent use of a rubber hammer,

Also be careful with the type of grease used as some impellers dont like various petroleum products although it usually is gone with in a few hours,

Cheers Steve
Click to expand...

Another vote for using silicon grease. I've always used Dow Corning compound 4 and found it makes it easier to get the impellers on and back off when the time comes. That impeller tool looks fantastic.
 
I think it was about $100 for the Sherwood 1700 size, including shipping, via PayPal...

-Chris
 
CaptSteve53 said:
Some Silicon grease on the impeller it'self makes a big difference and a little on the shaft for easier removal next time , quite a few impeller suppliers include a little tube of silicon or other grease with the impeller, Yes the larger impellers can be a real struggle to fit, just to note when bending the rubber impeller vanes to pass the cam, be sure you bend in the correct direction of rotation other wise even though they do normally flip around, you can damage them, once started in the housing I often use a little gentle force in the prudent use of a rubber hammer,

Also be careful with the type of grease used as some impellers dont like various petroleum products although it usually is gone with in a few hours,

Cheers Steve
Click to expand...

OR go up to the Adult Toy Store and buy some lubricant.
It comes in water soluble and liquid silicon. No need to buy the flavored kind, your engine wont care. SMIRK
 
Clemson101 said:
It is shameful for me to admit I toasted my impeller due to not re-opening the fresh water engine intake seacock after systems check. Luckily (I thought) I had a spare onboard. After removing the old impeller, I attempted to install the new one. I applied some Dawn to the new impeller but could not get it to engage more than half way. After 3 hours of making various attempts to twist the new impeller and checking for obstructions or if there was a "key" notch (not one I could find), I finally had to call Boat US. Attached a picture of the impeller housing. Any tricks to getting the new one back on?

My vessel is a 2015 Beneteau ST 34 with a 425 Hp Cummins Diesel model QSB6.7.
Click to expand...
 
Last edited:
An update from my 2017 post. I again toasted an impeller again today. Had a spare, used zip ties to compress the fins of the impeller, used a lot of lube everywhere and fashioned a sleeve out of my wife’s Evian bottle. Worked like a charm. I’m currently sitting her ordering another spare and I’m going to order the impeller installer previously mentioned. Hope it will never be needed.
 
I had similar problems on an 8.3 cummins with Sherwood pump. There were two issues;


First was just getting the impeller compressed and holding it compressed while tapping it into the pump housing. I tried zip ties and other things to no avail. It was like trying to pin down a greased pig. I finally bought a full cuff piston ring compressor and it worked perfectly for the compressing part of the problem.


The second problem was that as the impeller was driven back into the housing, the fins would expand out when they reached the water grate and would snag on it. Rotating the impeller would solve the problem, but you can't do that with a gear-drive impeller.


I finally realized that it was much easier and faster to remove the entire pump and do the impeller swap on the bench with the piston ring compressor, and being able to rotate it while tapping it in.


The lesson learned is that with a larger engine and pump, swapping impellers is not a trivial task. And definitely not something I would want to do in a hot engine room while disabled and rolling in crappy seas. This is why I always change them as part of routine maintenance, regardless of hours or apparent condition. I just don't want one failing at sea.
 
They are really awesome. No affiliation. But the tool allows me to be able to change the starboard impeller and makes the port impeller easier. The starboard impeller was almost impossible to change before the tool. The mechanics at the yard where the PO stored my boat said they drew straws to see who would get stuck doing it since it was so bad. Now I can do it in 20 minutes.
 
Clemson101,
You can avoid (or at least reduce the chance) of impeller damage due to forgetting to open the thru hull by installing an Aqualarm flow alarm. It is loud and sound anytime the raw water flow is not adequate (as in blocked thru hull, valve not open, etc.). They are not expensive, maybe $100. Easy to install.
 
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