lucky131969

I'm on my second reproduction 326 water pump(in 6 months). The first one leaked from the back cover, and the second one failed today (shaft walked back, pulley started grinding the pump casting.......less than 300 miles on the pump).

I'll preface my question by stating, the belts were not too tight (is an A/C car).

I want to put a new pump on this engine, and be done with it. That being said, I either want a quality 326 pump......or ......a brand new pump that will fit properly, taking into account the unique pulley (L76 with A/C),provisions for the compressor brackets, bypass, etc. This is not an NCRS car, so if I can pick up a quality aftermarket pump, that is dimensionally the same as the 326, I'm all for it.

Thanks in advance....

65 vette dude

Send your pump to Arthur Gould, or you can buy one from him. He uses only the best parts, and he rebuilds them to last.........http://arthurgouldrebuilders.com/about/

65tripleblack

The leaky back cover could have been sealed easily by straightening the cover and using a new gasket with Permatex or equivalent on both sides. I had the same happen and I used black RTV. Torqued the bolts to 8 ft-lbs metal-to-metal. No leaks now and never will be.

If the pump has been rebuilt more than a few times, then the bearing bore will not hold the bearing as well as a new one. This has also happened to me where the bearing walked forward and started leaking on a brand new pump. The rebuilder (Stewart Pumps)

http://www.stewartcomponents.com/

Rebuilt it a second time, for free, but sent back a note in the box saying that the pump could be reasonably relied upon to perform trouble free at speeds under 7000 RPM, but speeds above were at my own risk.

Stewart pumps use only genuine ***, American Made bearings. They provide services to many NASCAR teams, among others.

If you drive your car regularly, and subject it to severe duty from time-to-time, then you're much better off installing a new OTC pump. The bypass hose is not necessary and won't be missed.

lucky131969

Thanks.

lucky131969

I tried sealing the first pump...even let the RTV set up for 48 hours before installing....it still leaked.

I'll check out Stewart. I might explore 6k RPM once in a while, but that's it.

Ironcross

gentlemen, I could never see the benifit of a rebuilt water pump when new is probably just around the corner at a reliable new parts store......Airtex is a brand name sold at many parts stores....

lucky131969

Do you have an L76 or L79?

Ironcross

No, whats the difference, there both small block Chevys and all Vettes use the short pump

larrywalk

Not all SBC short water pumps are the same in C2 and C3 corvettes! Up to about 1969 or 1970, the pump shaft diameter was 5/8", but after this time, the Corvette short water pump got a stronger 3/4" shaft making pulley and viscous fan clutch interchangeability problematic. Further, the later pump with the 3/4" shaft locates the flange for the pulley about .150" farther from the block, so it is not as short as the "short" SBC water pump.

Guess why so many complain about belt alignment problems!

lucky131969

A few things are unique, that make finding an aftermarket (or reproduction a chore). I have an L76 with A/C, which means the pulley is unique(not to mention a bastard to find). The clearance between the back edge of the pulley and the water pump is very tight.....so if the hub is pressed on too far, it's an issue. Not all aftermarket pump cover bolts will clear my timing cover. I also want the correct provisions for the bypass, without using an adapter. I found a professional builder in the NCRS Driveline, that has an original GM1 casting 326, and guarantees his pumps for life. Yes, more pricey than the repros, but I'm done rolling the dice with this Chinese crap.

JohnZ

The change in the bearing/shaft/pilot size and hub bolt pattern occurred for the 1971 model year on both SB and BB pumps.