Rebuilt water pump impeller

[CHerdic]

I am attempting to install a rebuilt water pump on to the motor of a 28 tudor.
The impeller blades are rubbing on inside of the motor. Had the bearings and packing nut professionally installed (pressed on) and not driven on with my big hammer. Any recommendations to correct the problem. The old impeller was replaced because each of the fins had been broken off.

[Joe K]

Originally Posted by CHerdic

I am attempting to install a rebuilt water pump on to the motor of a 28 tudor.
The impeller blades are rubbing on inside of the motor. Had the bearings and packing nut professionally installed (pressed on) and not driven on with my big hammer. Any recommendations to correct the problem. The old impeller was replaced because each of the fins had been broken off.

Others have reported issues with the impeller interfering with the interior of their heads. See previous post within the last month or so. This seems to be more a problem with the head than the impeller.

Best solution for you may be to cut down your impeller until the issue goes away. This will require some lathe work.

A clue might have been taken from your old impeller? Expect this may have been a modern pump rebuild (i.e. within the last 50 years).

Take heart in doing this. The Model A seems fundamentally designed with TOO MUCH flow and causing the upper radiator tank to overfill and overflow. By cutting down the impeller you may be solving two problems with one stone.

OBTW, I have a 50's era replacement water pump I bought simply because it was cheap and it was different. (no rollers in the nose bearing.) The impeller on this is about 1-1/4" inch in diameter - about 2/3rds the normal size. This one seemed to have served someone well for some time as it was worn out when I bought it. (but it may have worn out fast - like "economy" brake shoes.)

Joe K.

[Kurt in NJ]

If it is an original pump there is a thrust washer behind the impeller that could be out of place, ---perhaps it would move it 1/16"

If you have a copy of the service bulletins look on page 418

[Mike V. Florida]

Originally Posted by CHerdic

The impeller blades are rubbing on inside of the motor.

I have never heard if this problem (not that I doubt you). What I have heard, and it has happened to me several times, is that the shaft was too long beyond the impellers and was hitting the boss on the inside of the head.

[Joe K]

What I have heard, and it has happened to me several times, is that the shaft was too long beyond the impellers and was hitting the boss on the inside of the head.

For a while (and perhaps now) the parts vendors were selling a 'long' shaft to use on heads that were severely worn at the bridge area (this a natural tendency of course.) But I think that just the shaft. You place your own impeller.

Maybe impeller placed too far forward on the shaft? (i.e. shaft too proud.) This a problem that could result by following a direction enclosed with the shaft, either long or short. Or possibly from one of the "book" writers like Les Andrews (who has been er, incorrect in some other technical details.)

This maybe a case of "trust - but verify."

Joe K

[Dave in MN]

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Originally Posted by CHerdic

I am attempting to install a rebuilt water pump on to the motor of a 28 tudor.
The impeller blades are rubbing on inside of the motor. Had the bearings and packing nut professionally installed (pressed on) and not driven on with my big hammer. Any recommendations to correct the problem. The old impeller was replaced because each of the fins had been broken off.

Hey guys...note that he is saying the impellor blades are hitting the head...not the shaft. I have seen this twice in assembling engines to run on my test stand. Always with new impellors...and they do interfere with the head as you describe. My solution was to note the area of interference (rub mark) on the impellor and then to carefully grind away the required material. Care taken to remove the same amount from each blade/area of the impellor to keep it in balance.. Once clearanced, I took a couple more thousandths to make sure it still cleared after metal expansion (from the heat) of the components.
Note added 3/23/13: The two times I have seen this, the interference between the head and the impellor took place far before the contact area of the waterpump shaft approached the wear surface of the head. The pumps I was fitting were leakless/ball bearing assemblies with staked shafts. The only way to allow these pumps to fit was to remove some of the impellor blades/vanes.
Good Day!

[Mikeinnj]

I had the same problem and instead of wrecking a new impeller, I drilled and tapped the thrust end (where it makes contact on the boss inside of the head) of the pump shaft for a 3/8" X 1/2 " brass screw which ,then by using a various number of washers, took up the end play leaving .005 to .010 for expansion, and it also moved the impeller away from contacting the head. Worked great ! Of course the locking shaft collar sold by vendors like Bratton's will accomplish the same thing.

[Purdy Swoft]

I usually buy the 1/4 inch longer stainless shaft with pinned impeller. All of the old original heads usually have the boss in the head worn back. If the shaft is too long, it only takes a few seconds to grind it with my bench grinder. New heads don't need the longer shaft. The shaft with pinned impeller is the best and easiest way to go and I don't worry about the small amount more in the price. This removes any doubt about whether the impeller is correctly placed. I hear that the new impellers are easy to break. I grind the tips of the impeller to reduce the flow. I have never had the blades of the impeller rubbing the inside of the head, new or used.

[Joe K]

I just caught up with Dave's bolding. Yup. Too short a shaft extension can be as detrimental as too long a shaft extension - but for different reasons.

Good mental catch there Dave.

Joe K