Wouldn't hold air, compression ring worn out.  Bought the electrical on/off unit, still wouldn't build up more than 30 lbs.  air. Bought compression ring kit K-0650-SBD with sleeve and gaskets. Would only build up to 30 lbs. Then I bought the unloader check valve, still won't build up more than 30 lbs. I bought all this from MasterToolRepair. Is their products not reliable? WHAT DO i NEED TO DO?