Cummins QSM11 water pump impeller replacement procedure

[Jeremygavin]

I am in the process of changing the raw water implellors and wanted to ask what the correct “best” way to install the new impeller is. It is a sherwood pump and has 2 plastic clamshell type wear pieces on the inside of the pump that came out with the impeller when I pulled it out. I tried hose clamping the 2 halves together, put the impeller insidenand then tried to insert the whole assembly into the pump but I struggled to get the splines to line up with the shaft as the clamshells where holding it off center. Then I tried to install the impleller on the shaft first and then put the clamshells into the house pump but I couldn’t get the vanes to lay over enough to get them installed. I had to leave the boat to head to a softball game for my daughter so I will try again tomorrow morning. So, What is the best way to do this?

Thanks for the help.

 

[ttmott]

Sherwood changed the spline count and shaft size on the later pumps; seems like you have the wrong impeller for the pump. Pump G1814X takes the 18000K 14 tooth impeller and pump G2903X takes the 29000K 10 tooth spline impeller. The G2903X is the later pump.
Regarding the liners - only need replacement if blisters are on them. Be careful with them as they can crack very easily. Also don't let that little pin that goes in the back of the liner to prevent the liner from spinning get lost; that little pin will drop down and forever be gone. I have a tool that holds the liners in place so only the impeller is extracted....
From the school of hard knocks....

 

[Jeremygavin]

I have the correct impeller with the right spine count because without the liners it slides right into the shaft. It is the newer 10tooth spline. I think I may have lost the pin because it wasn’t in the liner. I will have to try to retrieve it tomorrow from the intake elbow. What tool do you have to keep the liner in place? Can you share a link to it?

 

[Havana Shamrock]

There’s a write up somewhere here on how to properly remove them
You need to put a few of the cover plate screws with washers back in after removing the cover plate that will prevent the clamshells from coming out.

 

[cod]

Ok, remove the cover plate. Take note of which way the blades are angled. Reinstall 2 screws with added larger washers at the location of the cam to prevent it from coming out with the impeller. If the cam was to come out, the key way could potentially drop down into the pump so you want to avoid that. After the screws are installed. Use the puller bolt that comes with the new impelller ( there are 2 types depending on the type of impeller you have). If it threads into the impeller, it will pull the impeller only part way. If you still can't remove the impeller, use a small socket and place it between the puller bolt and the pump shaft to act as an extension for the puller bolt. This will allow you to pull the impeller out further and eventually allowing you to just pull it completely out.
To install the new impeller, put a large zip tie around impeller and try and get the blade pointing in the proper direction. Remove the 2 screws. Put a little non-petroleum grease on the blade tips to allow it to slide in easy. Reinstall the cover plate with a new rubber o-ring.

 

[Jeremygavin]

Thanks for the info everyone. Now I know the clamshells are supposed to stay in the pump so I will install it that way. Hopefully I can find the pin that fell out. Thanks cod for the tip on zip ties. I will try that.

 

[ttmott]

Thanks for the info everyone. Now I know the clamshells are supposed to stay in the pump so I will install it that way. Hopefully I can find the pin that fell out. Thanks cod for the tip on zip ties. I will try that.

Hopefully all of this is happening on the starboard side engine; you probably have a chance retrieving the pin. The port side is another story; the fuel cooler is connected directly to that inlet elbow and what a pain that whole arrangement is..... If you end up having to pull all that apart on the starboard side, I would recommend relocating the fuel cooler from this

to this

 

[Jeremygavin]

Yes, I am “Practicing” on the starboard engine so I know what I am doing for the port one because just getting on the other side of the engine to get to it is a project. If I have to get in and out of that side numerous times figureing it out it would be a very long process. I am heading back down to the boat this morning and give it another try now that you guys have given me some insight on the best way to tackle it.

 

[dtfeld]

For what its worth...

I have CATs, and I'm in the process of what started out to be impeller change on the Sherwood 1732C's (I ended up replacing the entire pump). On my engines, getting the impellers out is difficult as there is limited room to get tools in/impeller out. I read several articles recommending pulling the entire pump off and replacing the impeller on the bench.

For me, this has been a much easier procedure. Those impellers can take a lot of force to get them started. It might be a little more time consuming, but I found this to be as good a way as any, as I have found that about 75% of my time is spent looking for dropped bolts/wrenches/sockets etc. when trying to do this in the boat.

 

[ttmott]

Yes, I am “Practicing” on the starboard engine so I know what I am doing for the port one because just getting on the other side of the engine to get to it is a project. If I have to get in and out of that side numerous times figureing it out it would be a very long process. I am heading back down to the boat this morning and give it another try now that you guys have given me some insight on the best way to tackle it.

Remove the, belt shroud, alternator, fuel cooler support bracket, oil return access cover, and bow thruster batteries; access will actually be almost achievable.

 

[cod]

For the port side, I place the tools and impeller (prepped with snap tie and grease) all in front of the engine. Then I coax the wife to go in front of the port engine. I then crawl back there from the rear of the engine laying on a long pillow. She then hands me the tools I need and the new impeller. Works well. Btw, I find these impellers to last an extremely long time.

 

[Havana Shamrock]

Steve I usually do all work on the boat alone so when doing the port impeller I bring my cellphone in with me and put it within reach just in case. It’s not a job for someone with clostrophobia for sure.

 

[Jaybeaux]

Steve I usually do all work on the boat alone so when doing the port impeller I bring my cellphone in with me and put it within reach just in case. It’s not a job for someone with clostrophobia for sure.

This reminds me of a funny thing my wife said. She can't believe the places I get myself into in the engine room, working in and around electricity, etc. She's said if something ever happened to me down there, there's nothing she could do. She'd have to get help. So she said she'd take a leisurely stroll down to the marina bar, order a nice and tall Gin & Tonic, sip and savor it for a good 45 minutes, and then start screaming for help. She wants to make sure I'm dead before the cavalry arrives! Ain't love grand?

 

[Jeremygavin]

Thanks for the help and ideas on getting the impeller in. I found the pin in the intake elbow below the pump and used washers to hold the clamshells in place like Joe suggested. Impeller went in fine with a little coaxing. Now the port side. If I don’t report back in 4-5 hours send help.

 

[Havana Shamrock]

Good news Jeremy I actually learned that trick from Steve(Cod)

 

[Jeremygavin]

I got the port done as well. I tried going in from the back of the engine but there was no way I was going to fit in there. As ttmott suggested I ended up pulling the alternator and alternator bracket and was able to go in through the front of the engine. Once the alternator and bracket where out of way it really wasn’t that tough of a position to work in.
Thanks again for the help.