Help Water Pump.

Shortdog

Shortdog

Member
IMG_0220[2].jpg

IMG_0235[1].jpgI haven't own this car long and I notice there was too much end play in the water pump. About 1/2 inch. The fan will not go all the way on the shalt. I have some knowledge in mechanics so I know this isn't right.

Question? Do I have the right water pump and wrong fan or the right fan and wrong water pump.
 
The water pump has to be bolted to the head to check the end play as the shaft
movement is limited by part of the casting in the head. This casting wears and
the end of the shaft can be built up, a longer shaft installed or a collar installed
on the shaft to limit its movement.

Bob
 
Fan and pump look compatible but the rear of the pump shaft is short allowing end play excess. Try changing the shaft or build in up with weld so do reduce the end play. I think it should only be .006. Check the head and see how much the thrust block in the pump housing is worn.
 
Bob C said:
The water pump has to be bolted to the head to check the end play as the shaft
movement is limited by part of the casting in the head. This casting wears and
the end of the shaft can be built up, a longer shaft installed or a collar installed
on the shaft to limit its movement.

Bob
Click to expand...

The water pump was bolted to the head when I checked it. The fan will not go on the shalt enough to put a carter key in. Johnny
 
Some repo shafts do not have the correct taper for original fans, and some repo fans do not have correct taper for original shafts. There was a run of both bad batches a few years ago with lots of similar complaints about not fitting. Is the fan metal or aluminum? 'Can't tell from your pump photos if these are original or older repo parts. A few years running repo parts in the water pump can cause them to look really old, especially if there is coolant leakage.
You can take a file and reshape the pump shaft end until the fan will fit on. I have also used a hand grinder to do the rough forming, followed by a hand file for final shaping. Go slow and fit often until the fan can be slipped snugly onto the shaft, far enough for the woodruff key to lock it into place. Ensure that the woodruff key is not too large or you'll never get the fan to fit.
Marshall
 
By the way, the correct terminology is "cotter pin" and "woodruff key", or "wedge key". I point this out, not to be persnickety, but in order to avoid confusion in future postings. There is a big difference between a woodruff key not fitting and a cotter pin not fitting. Using the incorrect name could send replies off in the wrong direction until the error in terminology is discovered, and the correct answer finally supplied.
Marshall
 
To reduce the end play of the shaft, the impeller must be driven farther up the shaft. To do this, open the jaws of a well-anchored vise and place the pump in with the back of the impeller resting on top of the vise jaws. Tighten the vise just enough so that the jaws touch the nipple end of the shaft. This rests as much of the impeller backside surface area as possible on the vise. Now take a BFH and strike the castle nut end of the shaft several times. The end of the shaft is usually even with the castle nut, so no smashing harm will come to either. That's also why you are using a heavy hammer, requiring only a few forceful strikes instead of a lighter hammer and many strikes. In this case, fewer is better.
Anyway, as you strike the end of the water pump shaft, that will drive the shaft "down" and impeller "up" the shaft. After a few whacks, remove the pump from the vise and check for end play. You want the impeller to fit close to the rear bushing inside the water pump body, but not binding against it. That odd-shaped flat impeller spacer will help maintain the proper distance. If necessary, repeat this hammering process until the impeller is where it should be. You will note that it has moved by the change in color on the shaft where the impeller had been.
Once you have attained the proper spacing, TEST FIT the pump to the cylinder head. You have effectively moved the shaft deeper into the cylinder head recess, so you may have file or grind away some meat on the end of the shaft to make it fits properly and still be able to spin. The idea is to have the end of the shaft spin inside the special flat recess just inside the head. That was originally intended to supply initial "pre-load" of the shaft. As the years passed, however, that area is probably well worn down. You may have to taper the end of the shaft after grinding because as you go up the shaft past the initial factory bevel, it gets thicker. Test fit the pump without a gasket first. When it is correctly fitted, you may feel a slight resistance when spinning the shaft. Now try test fitting with a gasket in place. No resistance should be felt. Then you are done. You could stake the impeller in place with a small Allen head set screw, but generally this is not necessary.
Some guys may cringe at the suggestion of whacking the end of the water pump shaft with a BFH. But that impeller moves realtively easily. If someone who wears suspenders and a belt is worried about ruining the end of the shaft and/or castle nut, he can remove the nut and re-install it backwards until it is flush with the end of the shaft. Then bang away! I have made loose water pump shafts with too much end play serviceable again using this procedure on many Model A's. It works!
Marshall
 
Marshall V. Daut said:
By the way, the correct terminology is "cotter pin" and "woodruff key", or "wedge key". I point this out, not to be persnickety, but in order to avoid confusion in future postings. There is a big difference between a woodruff key not fitting and a cotter pin not fitting. Using the incorrect name could send replies off in the wrong direction until the error in terminology is discovered, and the correct answer finally supplied.
Marshall
Click to expand...

Thanks it is a cotter pin. I went back and looked and I can cut just a little off the nut to get a pin in. After this there is still about .030 to .035 end play. The fan has to be aluminum because it is too light to be steel. Johnny
 
Marshall V. Daut said:
To reduce the end play of the shaft, the impeller must be driven farther up the shaft. To do this, open the jaws of a well-anchored vise and place the pump in with the back of the impeller resting on top of the vise jaws. Tighten the vise just enough so that the jaws touch the nipple end of the shaft. This rests as much of the impeller backside surface area as possible on the vise. Now take a BFH and strike the castle nut end of the shaft several times. The end of the shaft is usually even with the castle nut, so no smashing harm will come to either. That's also why you are using a heavy hammer, requiring only a few forceful strikes instead of a lighter hammer and many strikes. In this case, fewer is better.
Anyway, as you strike the end of the water pump shaft, that will drive the shaft "down" and impeller "up" the shaft. After a few whacks, remove the pump from the vise and check for end play. You want the impeller to fit close to the rear bushing inside the water pump body, but not binding against it. That odd-shaped flat impeller spacer will help maintain the proper distance. If necessary, repeat this hammering process until the impeller is where it should be. You will note that it has moved by the change in color on the shaft where the impeller had been.
Once you have attained the proper spacing, TEST FIT the pump to the cylinder head. You have effectively moved the shaft deeper into the cylinder head recess, so you may have file or grind away some meat on the end of the shaft to make it fits properly and still be able to spin. The idea is to have the end of the shaft spin inside the special flat recess just inside the head. That was originally intended to supply initial "pre-load" of the shaft. As the years passed, however, that area is probably well worn down. You may have to taper the end of the shaft after grinding because as you go up the shaft past the initial factory bevel, it gets thicker. Test fit the pump without a gasket first. When it is correctly fitted, you may feel a slight resistance when spinning the shaft. Now try test fitting with a gasket in place. No resistance should be felt. Then you are done. You could stake the impeller in place with a small Allen head set screw, but generally this is not necessary.
Some guys may cringe at the suggestion of whacking the end of the water pump shaft with a BFH. But that impeller moves realtively easily. If someone who wears suspenders and a belt is worried about ruining the end of the shaft and/or castle nut, he can remove the nut and re-install it backwards until it is flush with the end of the shaft. Then bang away! I have made loose water pump shafts with too much end play serviceable again using this procedure on many Model A's. It works!
Marshall
Click to expand...

Thanks Marshall. I will do this and let you know how it turned out. I not afraid to hit it with a BFH. By taking chances, is how I have learned to do somethings. After spending 20 years in the army, we learned to do a lot with very little.
 
Over the years, guys have staked their water pump impellers to the back of the shaft. Before you and your BFH go to work, look the impeller over for a slot head set screw or Allen head set screw. If present, remove that first.
Marshall
 
I tapped the thrust surface in the head and put a pan head screw in it so standard stock shafts would fit. --- the water pump in the car for the last 25 years was made with parts removed to make a leak less pump---- the leak less pump has been replaced 3 times, still using my not leaking stock pump
 
Buy a new fan if you have the same fitting problem with your new pump. As said some older fans were defective. They are made by one manufacturer and are all good now.
 
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