BELT SLIPPING ON FLYWHEEL WHEN HOT - Campbell Hausfeld 5HP 20 Gallon Single Stage Cast Iron Air Compressor VS5006

To solve the problem, first check the basic requirements for good function. The deflection of the belt should be 1/64 per inch of span between the centerpoint of the two pulleys. An example, if pulleys are 12" apart, the deflection is aprox 3/16". Next check for air leaks. With air in the tank at about cut out pressure, shut down unit and listen carefully for leaks (spray with soapy water) and repair as needed. Most likely leak is at the in-tank check valve. Remove the airline from the check valve and apply soapy water. If the check valve is leaking the pump with work extra hard to fill the tank. Clean the valve or replace if leaking. If no leaks, then suspect reed valves or head gasket. If reed valves or head gasket are leaking internally, the unit will take longer to fill and the discharge tube will be very hot. To keep track of the overall condition of your unit, you should know how much time it takes to reach cutout pressure. Ideal would be to time the unit when new then retest every month. If unit begins to take longer to fill, you know that a component is failing. Finally check that mounting bolts are tight and brace is not broken or cracked (some compressors have a very thin mounting plate causing the motor or pump to vibrate and the belt to wobble, a brace is added from the top of the pump to motor or motor mount). Good luck and let me know what you find.