V GOOLII G 2 5 cooling System Service Diagnesls Continued Condition Possible hose Correction HIGH TEMPERATURE 19 Excessive engine friction 19 Repair engine INDICATIONY OVERHEATING 20 Vehicle working beyond cooling 20 Install heavy duty cooling or Continued system capacity use special duty vehicle 21 Antifreeze concentration 21 Lower antifreeze content over 68 LOW TEMPERATURE 1 Improper fan being used 1 Install proper fan INDICA l ION UNDERCOOLING 2 Improper radiator 2 Install proper radiator 3 Thermostat stuck open 3 Replace thermostat 4 Improper fan pulley too 4 Install proper pulley small JOOLANT LOSS Refer to Overheating Causes in addition to the following BOILOVER 1 Overfilled cooling system 1 Reduce coolant level to proper specification 2 Quick shutdown after hard hot 2 Allow engine to run at fast run idle prior to shutdown NOTE Immediately after shutdown the engine enters a period known as heat soak This occurs when the cooling system is inoperative and engine temperature is still high If coolant tem perature rises about the boiling point it may push some coolant out of the radiator overflow tube If this does not occur frequently it is considered normal 3 Air in system resulting in 3 Purge system occasional burping of coolant 4 Insufficient antifreeze allowing 4 Add antifreeze to raise coolant boiling point to be boiling point too low 5 Antifreeze deteriorated because 5 Replace coolant of age or contamination 6 Leaks due to loose hose clamps 6 Pressure test system to locate loose nuts bolts drain plugs leak then repair as necessary faulty hoses or defective radiator 7 Faulty head gasket 7 Replace head gasket