Guy

My 1979 Smog pump spins freely with no bearing noise. A quick spin if the pump results in good air volume. There is some odd noise as the pump spins [whump, whump] . Despite my best search efforts, I can't discern whether this is normal. Most posts are related to bearing noise.

Normal?

Thanks!

M. Requin

When I isolated this weird sound to the air pump I took it apart and found the the vanes were worn and/or broken, although the bearings had remained sound. Might be worth a look.

Guy

Yep, bearings seem good and the vanes were good. The strips of carbon with the spring steel behind them were destroyed. filling the inside with ground up dust.

thinking of just removing the vanes for the time being....... the 79 doesn't use the air pump to the cat.