c3 smog pumps

[Bob W.]

Can anyone tell me if these pumps were used on any other GM cars or trucks ? And is there any stamps or casting numbers on them? Thank you Bob.

[Joe L.]

Re: c3 smog pumps

Can anyone tell me if these pumps were used on any other GM cars or trucks ? And is there any stamps or casting numbers on them? Thank you Bob.

Bob------


There were several different AIR pumps used over the C3 years. The several pumps used over 1968-78 period were also used across all GM carlines. The 1979 pump was unique to Corvette and some Pontiacs. The 1980 pump was used across all GM carlines. However, as far as I can tell, the 1981-82 pump was unique to Corvettes.

All of the pumps used during the C3 years were manufactured by the Saginaw Division of GM. There will be the Saginaw logo cast somewhere on the aluminum body of the pump. There is also a casting number on the aluminum body of the pump but it's not visible with the centrifugal filter installed. The cast iron rear plates of the pumps have a casting number on them which varies with the different pumps used over the C3 years. The pumps also have an assembly date and pump model code stamped into a machined surface on the aluminum body.

[Jerome P.]

Re: c3 smog pumps

The pumps also have an assembly date and pump model code stamped into a machined surface on the aluminum body.[/QUOTE]

Joe, where are these date and code stamps located on the pump body?

Thanks

[Edward B.]

Re: c3 smog pumps

Jerry, the date code is stamped on a machined flange (see attached) but it's hard to see when it's installed because it's under the pump.

Ed

[Jerome P.]

Re: c3 smog pumps

Thanks Ed.

Decoded what is the date that is stamped in your picture.

I located mine, but it is very hard to read. Location and upside down using a mirror is not that easy.

I initially came up with 1S621V, but it certainly could be different.

My A.I.R unit is on my June '72 build date car.

[Edward B.]

Re: c3 smog pumps

Jerry, the one in the picture (30681S) is the 306th day of 1968, first shift and the model of the pump.

More than likely yours is 15621Y which would be the 156th day of 1972, 1st shift, and the model of the pump.

The format is Julian day, year, shift and pump model.

Ed

[Jerome P.]

Re: c3 smog pumps

Much appreciated, Ed.