Hi,
Our aeration system stopped and when we checked, the gast rotary vane compressor was running but stopped pumping air. So we disassembled and (of course) found broken vanes. We replaced them and it started back up again, but it doesn't seem to be pumping air. At least not in the correct direction: air is coming out of the intake filter port. Did we somehow reverse the polarity of the motor or can anyone suggest what we might have done wrong? Thanks.
anthony

I gave Bill Cody a shout and here is what he said:

Pressure on the in port is because the pump is running backwards. The start switch might be or is probably damaged (lightning strike?) or was messed up for some reason when the pump quit running causing or need of rebuild. Running backwards could have caused the vane/s to break initially thus needing a rebuild.

Very low possibility the rebuild caused the backward running.

While still partially disassembled, we turned it by hand to start it spinning, plugged it in, and off it went pumping in the correct direction. We put the case back on and it's fine so far. But I'm kind of afraid to turn it off now. Is there something we should replace (do you think it's a start switch and if so, where is it and what part number should i be looking for?) to make sure it will work after a power outage, etc.?
Thank you.

I've had other compressor owners try to replace the start switch on the motor. Main problem is finding someone who will sell the motor start switch. Normally the start switch is on the inside upper back part of the motor. If you can find the start switch try spraying it with electrical contact cleaner.

I would test run the compressor on-off several times to be fairly confident it runs forward. Running backward it will want to pull water back into the airline and compressor. Water ruins the compressor. A check valve system will help minimize water sucked into the compressor.