Stuck Impeller

[Photolomy]

Trying to change impellers and it isn’t budging. I read few threads here, one said it was due to the cam, but seems like it is stuck to the shaft. I have tightened the puller hard, but it still slips. Thinking about getting some bolts in the morning from HD to enabling righting even harder, and a shorter pull bolt that will fit behind the transmission oil hose better. Any other ideas short of pulling the pump? I wanted to avoid that if possible, the pumps are new. Unfortunately, I don’t think the impellers have been changed since the rebuild in 2011. The impellers themselves appear to be whole, so not worried about bits and pieces.

 

[Briankinley2004]

On my 12V71's even with the puller I still have to assist with a couple of screw drivers on the sides. Tighten the puller then pry slightly with the screwdrivers. The puller just eventually comes off it I don't do this. This is even with new impellers.

 

[Boatsb]

Pull the pump. It's easier and it may need more than just an impeller.

I sent some "recently serviced" pumps off 8v92s to depco. The shafts were pitted, the bearings and seals were.worn and they needed more than just an impeller.

I don't bother with service on pumps more than 3 years old. I send them out and get the customer a fully serviced or new pump.

 

[racclarkson@gmail.com]

On my 12V71's even with the puller I still have to assist with a couple of screw drivers on the sides. Tighten the puller then pry slightly with the screwdrivers. The puller just eventually comes off it I don't do this. This is even with new impellers.

The screw drivers work, but pad them. Pump is soft; tools are hard. Can also use needle nosed vice grips on opposing vanes.

 

[Photolomy]

Pull the pump. It's easier and it may need more than just an impeller.

I sent some "recently serviced" pumps off 8v92s to depco. The shafts were pitted, the bearings and seals were.worn and they needed more than just an impeller.

I don't bother with service on pumps more than 3 years old. I send them out and get the customer a fully serviced or new pump.

If went this route, it is just the hoses and the bolts attaching it to the block, right? Will it pull right off, or will that shaft be stuck also? There seems to be "just enough" room to pull it. Not sure though about enough room to crack those three? bolts holding it to the block.

 

[Captain Ralph]

Is everybody assuming a Detroit pump?? Not noted in the O P for us dummies.
Spray quickly in the pump with WD40 as someone bumps the starter. This will resolve friction from the case or cam.
Rarely I really see a seize issue on the shaft.

 

[rustybucket]

One trick I've resorted to in the past is sharpening the jaws of the puller with a file/sander/grinder so they actually cut/dig into the impeller and grab it. I've used that trick on more than one stuck impeller. The only downside to it is you will NEVER be able to use that puller to pull an impeller you plan on re-installing. But really, how many times do you pull/reinstall an impeller? Don't think I've ever re-installed one I pulled, always go back in with new.

 

[davidwigler]

Squirt some Dawn between the vanes an turn over with the stop button depressed.

 

[ageless]

Squirt some Dawn between the vanes an turn over with the stop button depressed.

I would never have believed it but I've used WD-40, soap, and other lubricants but cooking spray has always worked the best. Spray liberally then follow the above directions

 

[Photolomy]

Thanks everyone. Dawn, turning the engine over and screwdrivers did it. It wasn't stuck to the shaft at all, just the friction of the neoprene and the housing. Once you know how and what you are up against, it isn't that hard. I had asked the yard where I bought the boat to change them before we brought her down, but they talked me out of it because they were new pumps, but still, 6 year old impellers seemed pushing it.

 

[Photolomy]

For the other engine, I am going to modify (grind) the puller and make the jaws dig in as mentioned. I was going to keep these as spares, but I will just buy new ones as spares and replace them every two years.

 

[racclarkson@gmail.com]

Impeller vanes take a set after a while. I will take a low operational hour but high static hour impeller and flip it 180 and reinstall. I don’t see the point of tossing an otherwise good part.

 

[Captain Ralph]

Thanks everyone. Dawn, turning the engine over and screwdrivers did it. It wasn't stuck to the shaft at all, just the friction of the neoprene and the housing. Once you know how and what you are up against, it isn't that hard.

The screw driver trick has one drawback, gouging the pump case. A nice flat file may need to be stroked over the face to ensure a smooth contact area to the cover plate.
A lil round file to clean up any burs in the impeller side of that edge also.

On other big Jabcso pumps like these, An O ring is fitted just at that same edge, screw drivers can not be used here or they will damage the O rings thin groove.

I have also witnessed people forgetting to remove the lil black disk seal and press against that with a puller tool and swear something is wrong.

 

[Captain Ralph]

I had asked the yard where I bought the boat to change them before we brought her down, but they talked me out of it because they were new pumps, but still, 6 year old impellers seemed pushing it.

I must have missed something somewhere else but I have to ask;
How do new pumps have 6 year old impellers?

 

[Pascal]

Looks brand new with a minimal set.

Some impellers have a thread in the hub so you put in a bolt and crank it up with a socket to pull the impeller out. Best system

 

[Photolomy]

I must have missed something somewhere else but I have to ask;
How do new pumps have 6 year old impellers?

The engines were rebuilt in 2011 (probably reinstalled 2012) and and got new pumps when they were rebuilt. When I bought her in 2018, the engines had 100 hours on them. The original owner (who bought the boat brand new) didn't use it much after the rebuild and suffered a stroke 2 years before I bought it. So, I guess the mechanic considered them still new and not worth the expense of replacing. We have put 300 hours on it since then. From the comments here, I guess the mechanic was pretty much correct, but obviously, those blades that have set were ineffective all this time. We did have two new impeller kits on board when we brought her down from Missouri. That is what I am using now for the replacement. I will buy two more and keep them on-board for next time.

I haven't had any engine temp issues. I just thought it was time that I change them out.

 

[Photolomy]

The screw driver trick has one drawback, gouging the pump case. A nice flat file may need to be stroked over the face to ensure a smooth contact area to the cover plate. A lil round file to clean up any burs in the impeller side of that edge also.

Good point, and I did notice that. I will clean it up. I think by modifying the puller a bit to get more grip, I will be able to get the other one out without using the screwdriver. I still have to put the new one in. That may be harder than taking the old one out.

 

[Captain Ralph]

Looks brand new with a minimal set.

Some impellers have a thread in the hub so you put in a bolt and crank it up with a socket to pull the impeller out. Best system

Sherwood pumps have a large thread. Newer Yanmars use a smaller size bolt.
It does make things easy.
Pascal, the later pumps for your new Cummins should have this option.

 

[Captain Ralph]

I just thought it was time that I change them out.

Yep, with that story, Yep and good job.

 

[Captain Ralph]

Good point, and I did notice that. I will clean it up. I think by modifying the puller a bit to get more grip, I will be able to get the other one out without using the screwdriver. I still have to put the new one in. That may be harder than taking the old one out.

Again, spray the hub, not the impeller, with WD40. Push it in with a twist motion till the splines engage. Straighten the impeller to square to the pump and tap in with the heel of your hand a few times. With your fingers, help flatten the blades that need to fold down on the cam (should be easily visible) and tap a few more times to insure your really on the shaft. Here I take a small block of wood (saves your hand) and tap in the impeller till in.