Vacuum pump trouble

"Michael O'Connell" wrote: I've seldom used my vacuum pump but when I recently tried all that happened was a continous hum. ^^^^^^^^^^^^^ Meaning it wouldn't turn? It is not unusual for a Gast pump that is not run for a long time to gum up and be hard to turn. Can you turn it by hand? Easily, or does it feel stiff? If it's easy to turn, it's probably the motor*. If it feels stiff, you may be able to free it up by shooting some solvent or WD-40 into the pump suction and forcing the rotor around by hand until it frees up. If it won't turn at all, or turns easily and hits a "stop," you may have a broken vane. This requires disassembly. There is a Gast dealer in San Rafael: James Wilbee, 150 Bellam, 415-457-6880. (This info is several years old.)

*Disconnect the motor from the pump and see whether it spins easily, and whether it runs. Could be a bad capacitor or starting switch. Sometimes just blowing the dust out of the switch with compressed air will fix it.

hum = motor not turning - if you let it hum for several minutes you may well have burned out the start windings on the motor, I don't know that specific motor - the carbon blades are probably rusted into place - what I would do is disassemble the pump, remove the blades and make sure it runs, then with some emery cloth, clean off the rust and reassemble - and remember to run it at least once a week for a few seconds to a minute.

bill