67' L 79 water pump pulley-A/C no P/S

[Jay]

Would anyone Know the correct part# (or replacement #) for the water pump pulley on a 67'L79 327/350 L79 with A/C, no power steering? Is it a deep groove pulley? Chicago Corvette and Corvette Central list it as a #904...The Corvette Assembly Manuel lists it as #3890419...a 5/23/66 drawing!

My present A/C compressor belt(Quanta/GM restoration belt #3847705)sits pretty high in the outer groove of the water pump pulley. It is a wider belt than the inner alternator belt, which sits fine in the pulley. The belt also wobbles back & forth a bit, as if possibly not offset properly. (I am running the correct #326 water pump)

I'm afraid of the belt popping off the pulley!

Any help or sugestions?

Jay #31894

[Joe L.]

Re: 67' L 79 water pump pulley-A/C no P/S

Jay-----

The correct replacement pulley for your application is GM #3995641. This is a 2 groove pulley of 5.9" diameter. It currently GM lists for $37.85. If, using this pulley, you still have problems, then your problem lies elsewhere.

[Pete Lindahl]

Re: 67' L 79 water pump pulley-A/C no P/S

Jay - You mentioned the belt to the AC compressor might have an alignment problem. Assuming the alternator belt is aligned and the water pump pulley and shaft are OK, you might check and see that the front AC compressor support bracket (3841697) where it attaches to the water pump or to the lower support on the exhaust manifold isn't broken. Also check the front and rear bolt bosses of lower bracket (3878222) to see that that bracket isn't broken. I've seem them broken and in that case the front of the compressor might not be attached thoroughly or supported correctly and could contribute the misalignment. If the alternator belt also has an alignment problem, you might check the water pump hub location on the shaft. The specification should be in the service manual. Pete

[Pete Lindahl]

Re: 67' L 79 water pump pulley-A/C no P/S

Jay - One other thing I forgot to mention is that the L-79 C-60 compressor installation should have two washers between the front support and the front bracket that attaches to the compressor. Check out the '67 Corvette Assembly Instruction Manual page for the L-79 C-60 Compressor Brackets (UPC C1). It shows the two washers (#19 3706737)located between the support (#9 3841723) and the front bracket (#2 3841698)that attaches to the pulley end of the compressor. So while your at it you might check to see if these are installed, since they impact the alignment. Pete