Gauge High No Blow Off From Cap or Steam From Reserve Tank

High Gauge Reading - Hot Weather - Heavy Load:

1. Verify gauge reading. Is a high temperature reading indicated?
^ Compare gauge reading to High Gauge Reading illustration above.

2. Gauge reading at "H" without signs of boiling.
^ Inspect For grounded gauge, sending unit or circuit.

3. Low coolant level in radiator and coolant recovery tank.
^ Fill to full.
^ Inspect for leaks in system and repair as necessary.
^ Ensure radiator pressure cap was shut tight. Verify proper operation of the radiator cap upper and lower seals.

4. Coolant level in radiator is low, but not low in coolant reserve tank.
^ Fill to full.
^ Inspect for leaks in the system and repair as necessary.
^ Inspect for leaks in the coolant reserve tank to radiator hose.
^ Verify proper operation of the radiator cap upper and lower seals.

5. Test coolant freeze point.
^ Adjust coolant solution to 5O/5O mixture of antifreeze and water.
^ If a reading is not recorded or below -50, the mixture is too rich. Clean system and fill with a 50/50 mixture of anti-freeze and water.

6. Ensure proper coolant flow.
^ With the thermostat open and a slight amount of coolant removed, inspect for coolant flow through the radiator filler neck opening.
^ Determine reason for lack of coolant flow and repair as necessary.

7. Other possible causes.
^ If symptom occurs during high speed operation, inspect for plugged air inlet side of the radiator or condenser, plugged radiator core tubes, add on A/C package without proper radiator, engine not operating within specifications, dragging brakes, trailer towing or hill climbing, or an insect screen.
^ If symptom occurs during high or low speed operation, inspect for thermostat being stuck partially open if ambient temperature is below 70 ° F and the vehicle has high mileage, plugged air inlet side of radiator or condenser, add on A/C with incorrect radiator.
^ If symptom occurs during low speed operation only, inspect the radiator fan drive. Repair as necessary.