Ryobi 1.5 HP compressor. We seem to be getting air pressure. The gauge does not move off zero but when we release the pressure valves afterwards there is plenty of air released. However, we're not getting any air through the pump hose.

SOURCE: My EC12 builds up pressure, but then releases all but about 10 psi.

The non-return valve is sticking and it's an easy fix. First, for safety, unplug the electric power to the unit and release any pressure in the tanks. Then unscrew the cap of the non-return valve (between the compressor and the tanks). Inside you should find a tapered rubber plug which is probably sticking in the valve housing. Sand down the diameter of the large end of the plug, being careful not to damage the flat face at the narrow end (which is the sealing surface). For sanding try 400 or 600 grade wet-or-dry paper and sand until the plug just moves freely in the housing. Reassemble and the compressor should work. Incidentally it's an oil-type unit, and quite durable. Make sure it has enough oil.

SOURCE: WILL NOT BUILD PRESSURE

Many craftsman compressor are built by champbell hausfeld using a dry type of cylinder and piston (no oil, no crankcase). If dry type, check for worn cylinder and piston ring. Pieces of the vinyl ring can jamb between the reed valves in the head causing air to escape from the intake. If your compressor has a crankcase and oil, check for broken reed valves in head. Spray soap solution on hoses, checkvalve, drainvalve, and fittings to check for leaks. Most likely problem is reed valves broken or open. Parts are available from sears or match parts to chpower.com. enjoy

SOURCE: Air leakage through pressure switch needle

1)Let your unit pump up.
2)Turn it off.
3)Find the supply line from the pump to the tank.
4)Remove the supply line from the pump head.
5a)If you hear air coming from the tank you have a bad check valve.
5b)If you do not hear air coming from the tank, you have a leaky
pressure switch.

SOURCE: Air pressure gauge does not move on Craftsman 1Hp, 12 Gal. Air Co

I would say that the gauge needs to be replaced. These are common items so go to any auto parts or craftsman hardware store and purchase a replacement.

be sure to use some joint compound or teflon tape on the threads so u dont have any leaks.

please rate my answer. thanks.

SOURCE: Ingersol T30 won't shut off and blows pressure release valve

the wire juction box on your compressor has a pressure switch that may be wound in to tight take the cover off the box there should be a switch with a machine screw with nut and washer and spring back this nut off and see if that helps if you go to far you just crank it back in until the switch hit although it may be the other way around you may have to tighten to lower the pressure some of them are made that way if this does not solve your problem send me a picture of the switch and can solve it from there