My garage air compressor wont start cold when the tank is full,when its warm its ok but now stops before the max build up.

SOURCE: Pressure won't build up in tank

Your compressor is the oilless type that incorporates a vinyl/teflon piston ring and a cylinder that is open from the bottom. Remove the cover and push the piston to upmost position. Look for scratches along the upper portion of cylinder. If scratched, compression is leaking thru ring and will not fill tank. Replace with Sears part #k0650 cylinder /piston ring kit to restore full power. While the compressor is apart examing the valve plate and reed valves for wear. If worn replace with part #z-ac-0032. Reed valves tend to crack or loose their shape reducing efficiency. If cylinder and ring are in fair condition, then most likely reed/valve plate is the problem. Good luck and email if you have more questions.

SOURCE: air compressor problem

Cheap oil-less compressor, normal.
If you don't like it, buy one that uses oil and a drive belt.

SOURCE: coleman powermate inflationmate pump

The ring is gone on compressor. You can buy replacement pistons and rings from colemen. Comes with instructions.Good luck

SOURCE: compressor will not build pressure

compressor will not build pressure

Joe Garcia

• 210 Answers
• Posted on Mar 23, 2009

SOURCE: air compressor fills, but slows down as the pressure builds

sounds like you need a new check valve which should be somewhere between the compressor outlet piping,tubing,etc and the tank which prevents the air in tank to back feed to the compressor which would cause hard starting and could damage the motor easy way to check is when you shut off the compressor with some air in the tank if the check valve is bad it would continue to bleed air out out the unloader valve .the unloader valve on your unit is most likely part of the pressure switch when the unit shuts of it should only bleed down the pressure in the pump so it would make it easy to start when needed hope i didn't confuse you