Removing pump impeller

[ldj]

Have a Pioneer water pump on a 4 cylinder engine. Have it apart down to the impeller and there is a bolt going through it to the shaft. Have removed the bolt and can't get the impeller off. Don't know if it is tapered shaft, splined, or screws on. I have saw impellers that screw on but don't remember if they had a bolt through them also. Anyone have a clue how to get it off? With that bolt through it, would that mean it isn't screwed on?

 

[Anonymous-0]

Could be either way screw or tapered, you need to find a book on it or look at a new impeller if you can any thing. hopefully some old time pump guy will read your post.

 

[J-TEX]

look in the end of the shaft/impeller opening and see if you can see a key way. i have books on them if you can get me a model # of the pump I can find out for sure. or you can call the factory @ 503-266-4115. I am pretty sure thay are keyed which will require a puller with easy pressure on it so as not ot bend or distort the impeller.

 

[Chris (WA)]

Take a block of wood and a hammer and try to spin the inpeller in the direction of rotation. Shaft is threaded so pump drive rotation tightens the impeller onto the shaft. A couple single hard blows usually does the trick.
If its keyed/ tapered I have seen where the hollow end of the impeller is threaded . You screw a bolt into those threads and tighten it. It acts as a pusher and pushes the impeller off the shaft.

 

[oldhousehugger]

If the metal of the impeller is made of a different material than the shaft, it will have a different thermal expansion coefficient. According to an old engineering textbook, the cast irons and steels run between 5.5 and 7.5 (x10(6th)).
The bronze alloys run around 15 to 20 (x10(6th)). Aluminum is between 26 and 27 (x10(6th)).
What this tells me is that as you heat the whole mess up, the steel shaft will get bigger SLOWER than the impeller if the impeller is bronze or aluminum. As long as you stay well below the melting points of your alloy casting the casting will eventually lose it’s grip on the steel shaft and the casting should get loose enough to slide or unthread off. As long as you don’t get the shaft into the 1100F degree range your temper should remain untouched.
I have had pretty good luck getting pressed in steel bearing cups out of aluminum castings by heating up the unit until the paint starts to smoke (350-400F). The bearing just falls out when it the difference in size releases the bearing. If your oil seal on the engine is easy to get, heat the impeller and if you smoke the seal just pull it out and put in a new one. Heat could be your best friend here.
John