Assembly - fan to water pump

1

1912Krit

Member
This morning I was on my merry way reassembling my water pump and 2 blade repro fan from Snyder's. When I mounted the fan on the shaft with keyway, the fan pulley dropped down over the water pump casting but when turned it scraped the casting. I removed the fan and put a spacer between the casting and fan, which gave enough room with mini clearance for the fan to turn without scraping the casting, but now the bolt holding the fan on the shaft will only catch a few threads, not low enough to get a cotter pin through.

Any suggestions?
 
A spacer is not a correct answer to this issue. The reproduction water pumps until recently were not quite cut round so they rubbed on the pulley. You have to find the high spot and sand/grind it down until it does not rub no more.
 
That is odd in that case. It must be the fan if it is for sure an original pump. At any rate, you have to get rid of the high spot to use that casting.
 
I have seen this before. I suspect some pump housings were made by different aftermarket suppliers after the Model A went out of production and they vary in outside dimensions. The people making the reproduction aluminum two-blade fans may not be taking this into consideration. The ones I have been getting in recent years from Bratton's all have fit ok and were in excellent balance. I have a balance testing rig.

One option is to find where the inside of the fan is hitting the housing and grind some material off the pump housing.

Tom Endy
 
Thanks for the info. I think the problem is the taper in the fan. The shaft and rebuild kit fit perfect. However, the fan slides all the way back to hit the housing and only in that position will the end bolt tighten just enough to get the cotter pin through - but the fan pulley is jammed against the housing and won't turn.

It must be that the repro fan is defective?
SXLfmHk
 
The water pump is from my 1930 Ford roadster that my Dad bought in 1948 and stored until I got it running last year, and then I tore it apart to rebuild engine and restore it. The water pump was never removed from the car, at least not since 1948!
 
Brent in Tenn O See may have the original waterpump drawing to use to measure what you have. Most folks will grind down the waterpump casting. Consult Snyders or try a fan from another vendor.
 
I would hesitate on grinding on fan blade hub as it may unbalance it , being a casting rather than a stamping it is thicker than original.
 
The grinding needs to be done on the pump body. different manufacturers made pumps. I have a GM pump! The fan is a good reproduction, maybe look for a burr or flashing in the casting
bore and collar.
 
The aluminum fan IS a good reproduction part. What we do have to remember that it is an aluminum casting as opposed to the stamped steel original. In order to make the correct dimensions for the fan belt and maintain the strength and structural integrity of the pulley, the inside diameter of the pulley hub is smaller than an original steel fan. Grinding the inside of the fan hub is not a good idea as it will weaken the casting. On the other hand, grinding down the nose on the water pump to allow for enough clearance will probably not hurt the integrity of the cast iron water pump housing. I understand thinking you may be somehow "defacing" what may be an original pump housing but, even though you know the history of the car, there's still a very good chance it is not the pump that was on the car when it left the factory.

Good luck. Bob Bader
 
You didn't show the opposite (impeller) end of the shaft. Is the impeller pressed on or pinned on the pump shaft? Is it possible to move the impeller position?
 
Chances are good that the water pump had been replaced a couple of times between 1930 and 1948.Coolant was water and alcohol,anti-freeze with lube was not in everyday use yet.Plus,greases at the time were nowhere the quality of todays.Zinc packing nuts would seize,break up and crumble,the rear bushing would wear out quick,an original untouched water pump would be a stretch.Make sure the teardrop washer is seated under the impeller,and not up on the notch of the casting.Grind the body until the fan fits and spins freely.Also,take the key out and scribble with a magic marker on the taper of the shaft.Slide the fan on,hold the impeller in one hand and spin the fan on the shaft with the other.Pull it off and check the contact area on the shaft.The ink should be pretty well scraped off.You are after 100% contact between the hub and the shaft.
 
when the when was installed, did the pulley line up with the crank shaft pulley. I suspect it does not. if it does then grind the water pump housing down. if it does (not) line then the shaft is not protruding far enough out of the pump. if the impeller is pinned in place remove the pin and press the shaft forward. and re-drill it.

remember the fan needs to be all the way on the shaft and tight. or you could kiss your Radiator good by.
 
If you move the impeller, pin it or make sure it won't come loose. Radiators are expensive nowadays!
 
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