Ok fellas I need to know if I can revert from a 3/4" pump to a 5/8" pump. Mine started leaking today, less than a year after buying it from NAPA. I would like to switch to the 5/8" pump as they seem plentiful. I can easily make a bushing for the water pump pulley. I have about 1/2" of space between the fan blades and the radiator if that matters. Maybe I can rebuild my rebuilt pump for a spare but time is a issue as this is my daily driver at the moment.

 

If I remember correctly, the pulleys don't line up. So in addition to a bushing, you need a spacer. You may have just got a bad rebuild.

 

Thanks for the input, looks like the 5/8" is not "on the shelf" either. So I ordered another 3/4" unit from Autozone. In the mean time I put a bottle of K Seal (copper based) in and presto, stopped leaking.

Curious of what seal type the Y block has. Is it a modern neoprene seal or a packing gland?

 

Unless it was rebuilt during the Carter administration it should have a lip seal.....LOL

 

Funny, I get it!

 

Well now that I bought a replacement, the leaker's not leaking, not one drop. Guess I can extend the life of this one for a while. to K-seal

 

It's Murphy's Law. Keep it and everything you need to change the pump in your truck at all times and it'll never leak again. As soon as you start out on a road trip without it...........................