Got a Husky 6 gal pancake, 1.5hp. motor runs- no air pressure ??

could be a possibility. Clanking or rattling: Loose internal mounts can cause rattling and clanking from the compressor. The sound probably means that the motor has come loose and is moving around inside the sealed compressor can

is it building up any pressure on the gauge
if the pressure recorded is around 40 psi or less , replace the failed poppet/reed valves in the compressor head
if it goes to 100 psi then replace the automatic controller for the motor

have you checked the ring and cylider or the valves?

Either the compressor is bad,but more likely the connector went bad or broke.

Turn the pressure adjustment knob in to get the desired pressure.

Have you turned the knob on compressor regulator clockwise.?

PRESSURE REDUCER valve

I am a little confused here ... I have a Craftsman pancake, a Craftsman 6 hp (same compressor design) and several other name brand pancake compressors at the job. The compressor doesn't care which way the motor runs though mine all run in the same direction. As long as the piston goes up and down, the reed valves know when to open and when to closed based on the pressure. It sucks in from the 'room' on the down stroke and blows into the tank on the upstroke.

Yours isn't doing this? If it is creating a vacuum in the tank, I would have to say someone put the valves in upside down.

This is very curious.

You could reverse the black and white wire but as I understand the physics of it, it will not matter where the hot wire is since it is AC. The motor may be reversable but I'm thinking it is probably not in this case. That costs extra to make into the motor.

Please inspect the valves to make sure they are capable of 'inhaling' (the site will delete the other word I used) on the down stroke and 'exhaling' into the tank on the upstroke.

Please let me know what you find out.

Thanks for your curious question at FixYa.com

sounds like valves in head have failed and need to be replaced, that is where I would start looking first.

If there is pressure at the pump, either:

1) The tank check valve isn't opening (it's located where the line from the head enters the tank - usually extends into the tank, and the the pressure switch unloader line comes off of it as well)
2) The pressure switch unloader is bleeding off the air. This is a small valve on the side of the pressure switch. It should close when the compressor is running and open when the compressor shuts off to bleed off head pressure.