AIR CUIIDITIUIIIIIG 13A 3 Prassura lllaqnnsis Condition Possible Cause Correction LOW SIDE LOW 1 System refrigerant low 1 Evacuate leak test HIGH SIDE LOW and charge system LOW SIDE HIGH 1 Intemal leak in com 1 Remove compressor HIGH SIDE LOW press0r worn cyli nder head and inspect compressor Replace valve plate assembly if necessary If compressor pistons rings or cylinders are excessively wom or scored replace com pressor 2 Head gasket leaking 2 Install new cylinder head gasket 3 Expansion valve 3 Replace expansion valve 4 Drive belt slipping 4 Set belt tension LOW SIDE HIGH 1 Clogged condenser 1 Clean out condenser HIGH SIDE HIGH fins fins 2 Air in system 2 Evacuate leak test and charge system 3 Expansion valve 3 Replace expanison valve 4 Loose or worn fan 4 Adjust or replace belts belts as necessary LOW SIDE LOW 1 Expansion valve 1 Replace expansion HIGH SIDE HIGH valve 2 Restriction in liquid 2 Check line for kinks line replace if necessary 3 Restriction in receiver 3 Replace receiver 4 Restriction in condenser 4 Replace condenser LOW SIDE AND HIGH 1 Air in system 1 Evacuate leak test SIDE NORMAL and charge system INADEQUATE COOLING 2 Moisture in system 2 Evacuate leak test and charge system Add 2cc of anhydrousmethanol for each pound of refrigerant used