Drops compressiom from 120-60 psi after 3 new pressure switches
When the pressure switch fails the comperssor will overpressure to the point of safety release at about 150 - 160 psi. It sounds as if your compressor is not producing enough pressure to cycle off at 120 and just keeps running. This happens when air is leaking from fittings or worn cylinder / reed valves. Don't worry, with some simple tests we will find the actual problem. I am assuming that your compressor is oilfree type. If there are leaks the compressor may not reach set pressure. I use soapy water on all connections and on the head/headvalve (remove plastic covers to get to all parts that may leak) while compressor is running. Make repairs as necessary. If still low pressure, while compressor is running and has reached max obtainable pressure (in your case 60 lbs), carefully place finger over intake port hole (remove filter). If the compressor is pumping normally but leaking there will be ample suction at intake and cause the compressor to speed-up when intake is obstructed with finger. If you feel plenty of suction and no visible (soapy water) leaks, then the problem is probably the cylinder /ring is not correctly seating /scratched and air is leaking past cylinder. Make sure that the cylinder /piston ring is properly aligned and that the lip on the vinyl ring is up toward the head. On oilfree compressors you can examine the cylinder by pushing the piston all the way up, then look for scratches neer top of cylinder. If scratched, pressure is leaking past cylinder, install cylinder kit. If you do not feel suction but rather air blowing out of the intake, (do this test when tank has reached 60 psi) then the problem is the headvalve plate/reed valves are leaking. The reeds must seal perfectly on their seats and not be bent or have obstruction. Replace as necessary. If reeds or headgasket is leaking the discharge air will be very hot. Only one other thing to check and that is the intank check valve. Easy to check. Run compressor till you have about 50+ lbs in the tank then unplug compressor. Carefully loosen the inlet hose at checkvalve and listen for air leaking out of tank. (check valve is the brass valve at tank) If leaking replace checkvalve. Use caution when removing head to try and save the gaskets. If you have oil type pump, and no air leaks (soapy water test) suspect reed valves/valve plate. Good luck on your repair and email if you have other question.
May 06, 2009 |
Campbell Hausfeld 28 - Gallon Air...