A.I.R. Pump Diagnostics

[Tim S.]

My newly aquired 70 LT-1 has an AIR pump that is now making noise. A very tinny / metal screech that comes and goes.
1. Is there a way to lubricate it?

2. Is this a common problem and what can I do to avoid it in the future?

I should add that I reinstalled it after a 5 year nap on the shelf. The prior owner knew nothing of a problem

This is the first car I have had with emissions so, please excuse my ignorance.

Best Regards,

Tim

[Joe L.]

Re: A.I.R. Pump Diagnostics

My newly aquired 70 LT-1 has an AIR pump that is now making noise. A very tinny / metal screech that comes and goes.
1. Is there a way to lubricate it?

2. Is this a common problem and what can I do to avoid it in the future?

I should add that I reinstalled it after a 5 year nap on the shelf. The prior owner knew nothing of a problem

This is the first car I have had with emissions so, please excuse my ignorance.

Best Regards,

Tim

Tim------


There's no way to lubricate the pump.

Noisy AIR pumps are common. If the noise is caused by the vanes, there's no way to correct it except replace the vanes. If it's caused by the bearings, there's no way to correct it except replace the bearings.

Even after a complete rebuild, the pumps can still be somewhat noisy. Pumps that sit unused for a long time are usually noisy, especially if they were previously used and then taken out of service for a long time. I don't know why.

[Harmon C.]

Re: A.I.R. Pump Diagnostics

The spool inside rusts and the close clearances make the noise. I have had some luck to quiet a pump by adding oil through the hole in the top front of the pump.

[John H.]

Re: A.I.R. Pump Diagnostics

The most common A.I.R. pump failure mode is the vanes seized to the pump housing walls, which locks up the rotor; this is usually preceded by the noises you describe. Removing the vanes and replacing the bearings will make it live forever, essentially as an idler pulley.