Fan to Water Pump Fitting

[marty in Ohio]

Last week we put on a new leakless water pump and a new aluminum two blade fan. We put the fan on the pump shaft and put on the bolt but could not turn the fan (this was off the car.) Found that the fan was rubbing on the pump casting. Included with the pump was an instruction sheet stating that they may not fit and the pump casting may need to be ground down (Of course you always read the instructions later.) After a lot of grinding and filing we got it to fit. Has anybody else found this problem?

Marty

[Mulletwagon]

Went through the exact same drill. Cleaned up the pump snout with a file and was good to go.

[rocket1]

Makes me wonder why the fan is not made correctly to fit the pump snout!

[PalAl]

Yes had the same problem, lots of filing. Don't understand why this is not addressed by the manufacture rather then having instructions of how to fix a new part so it will work.

[bobbader]

The situation is that the aluminum fan is a casting and in order to have the strength needed for it to hold up, the inside dimension of the pulley around the nose of the water pump is slightly less than that of a comparable original pressed steel pulley. The other side of the equation is that water pump castings from different manufacturers can vary greatly in this area and, in actuality, can be very crude as far as finish in said area. The remedy, from the factory, would be to turn this part of the casting down in a lathe. But, since the water pump manufacturers are not the same folks as the aluminum fan manufacturers, the connection goes unnoticed. Add to that the fact that there are, and have been through the years, many manufacturers of water pumps with different casting molds. There is only one manufacturer of cast aluminum fans. Some water pump castings are smooth enough that the fit of the fan is not a problem. Others require grinding or filing. These cosmetic inconsistencies do not effect the mechanical quality of either the fan or the water pump. Each are manufactured and machined in the specific areas that require machining for proper function. The solution to the fitting problem is relatively simple if one has basic shop tools. This might be a bit of an inconvenience upfront but, it will lead to trouble free operation in the long run. The simplest answer, of course, is to READ DIRECTIONS FIRST. Unfortunately, in our hustle & bustle world we often move on without doing so. We all do it from time to time.

Enough said. I hope this answers some of the "Why don't they just ………….." questions.

Bob Bader

[TerryO]

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I took a dremel and sanding disc and removed the powder coating from inside the fan hub and it fits ok. I didn't have to remove any metal and since it is aluminum it won't rust and is not visable.


TOB

[old31]

Marty, where did you purchase the part? I recently bought one from Snyders and it was fine.

Regardless of the fact that 2 or more manufactures make up 1 part the seller should be looking at and checking what they sell us.

[marty in Ohio]

Old31,
Mine came from Snyder's also.
Marty

[Mulletwagon]

Originally Posted by marty in Ohio

Old31,
Mine came from Snyder's also.
Marty

Me too.

[old31]

Originally Posted by marty in Ohio

Old31,
Mine came from Snyder's also.
Marty

Go figure, who knows why it didnt fit. Maybe it was made on Friday at 5PM.

[Keith True]

I have a couple dozen water pumps on the shelf,and last spring I bought two new aluminum fans.We got to playing with them,and found they fit all but four of the pumps.They will fit the four with minimal grinding.I also have an NOS late 31 single thickness fan,it won't fit on three of the pumps.I always found it is the pump that is the problem,the thicker aluminum always seems to fit the bulk of them.I have some old aftermarket Toledo pumps,both A and B.The A pumps just needed a quick file,the B pumps actually needed grinding just to mount the original steel fans.