Looking for expert opinion to check my work.

[The "A" Team]

The head and block should be flat and fit each other within 0.002 inch. One way to test this is to put Plastigauge on top of the block in various places and then bolt the head down without a gasket. There should be no pits or scratches. You can fill the pits and scratches with JB Weld and sand it flat with 240 grit paper wrapped around a flat file. The block and head should be meticulously clean with a final wipe with acetone. I found the Best brand graphite gasket with the copper spray to work the best.

Try tightening the nut at the front of the water pump. If that does not work, the taper in the fan and the taper on the shaft do not match and either a new fan or shaft or both are needed.

I just pulled the fan off. The shaft and fan seem to look ok, the key looks like it got a little chewed up though. I heard the fan is not supposed to be able to easily slide off the shaft after being installed. It was a little difficult to slide off, as I had to lightly tap it with a hammer to get to slide off, but I don't know if that counts.

 

[nkaminar]

The shaft does not look bad. Take the water pump off the engine so that it will be easier to work on. While you are at it you can check the boss in the head to see if it is keeping the shaft from moving aft. Fit the fan on the shaft without the key and see if it still rocks back and forth. You don't need to put the nut on. If a good fit then put a new key in and again check the fit. If still good then tighten the nut and put the cotter key in. You can use Loctite on the shaft (WITH THE KEY) to help keep the fan in place. If you want you can paint the pump add some packing if needed. If you cannot get the fan to seat correctly then you need a new fan and/or shaft. If the key is keeping the fan from seating properly, you can dress the key with a file or grinder. Do not change the thickness, just the height.

If the nut was loose the fan can chew up the key. Or if the key was the wrong size or installed incorrectly it could keep the fan from seating properly.

You may need to pull the radiator forward to be able to remove and install the pump. It will rock forward if the top radiator hose is loose and rods are removed. Bolts are available to mount the water pump that look like nuts and studs. This makes it easier to remove and install the pump. They are out of stock at Snyders but other vendors may have them. See https://www.snydersantiqueauto.com/product.htm?pid=979241&cat=41793. A dripless water pump is a nice thing.

 

[rotorwrench]

If the fan was run loose for a length of time, it may have damaged the internal taper. The steel ones can take abuse better but the aluminum type is the only two blade type fan available new these days. Some reproductions have issues with rubbing the water pump housing but the late reproductions seem to fit OK. I'm running one right now and it's working. Tapered shafts should be assembled clean and dry using proper torque. If a person uses anti seize, it can slip a bit and start working on the shaft. The modern water pumps have a stainless shaft and some don't have a very well made taper on them.

 

[The "A" Team]

Just to keep everyone in the loop while I'm waiting for my parts to arrive, I took the water pump off today and at least it's still in one piece, with some scuffing on the shaft where the fan was sitting.

A customer service agent from C.W. Moss responded about the fan and said I need a nylon washer and collar set that's supposed to go on the shaft to make the fan sit correctly. That's one of the parts I have coming, so we'll see. I'll give an update once I reassemble everything, and even give a video again if possible.

 

[Gary WA]

Just to keep everyone in the loop while I'm waiting for my parts to arrive, I took the water pump off today and at least it's still in one piece, with some scuffing on the shaft where the fan was sitting.

A customer service agent from C.W. Moss responded about the fan and said I need a nylon washer and collar set that's supposed to go on the shaft to make the fan sit correctly. That's one of the parts I have coming, so we'll see. I'll give an update once I reassemble everything, and even give a video again if possible.

Fan blade should be on there with no nylon spacers/washers! Key way should be half moon on shaft, square part to fan! tighten install cotter key. Probably due for a new head gasket!

 

[The "A" Team]

Fan blade should be on there with no nylon spacers/washers! Key way should be half moon on shaft, square part to fan! tighten install cotter key. Probably due for a new head gasket!

I don't know. They said sometimes the aluminum fans don't sit correctly on the water pumps.

Here is what the rep said in his message:

"Hi John,

Sometimes on a Model A you need to use a Water Pump Set Shaft Collar to stabilize the fan. It isn’t always necessary but in your case it is. The part number is A-8511-C. This collar corrects the back and forth in a fan (what you are now experiencing)

Sincerely,

Troy Williams
CW Moss Ford Parts"


From what I saw, the collar sits at the bottom of the shaft against the housing, and then the fan sits against that to keep it from moving up and down the shaft. There was a guy on YouTube that was rebuilding a water pump and showed that collar in place.

This is the link to the collar piece:

https://www.mikes-afordable.com/product/A8511C.html

And here's the link to the YouTube video (he shows it around the 50 second mark):

https://youtu.be/Wcd-zIA1YrE