Powerstroke HOT
Begin by checking the fan belt tension. Next check the fan clutch for engagement. A dangerous method of checking fan clutch operation is, start engine and go for a short ride to allow engine to rise. Get a length of 3/4 heater hose and fold in half, While holding 2 ends, attempt to slow or stop fan from turning using the heater hose. If the fan can be stopped, the clutch is bad. Use care as this is dangerous and should be done while standing on curb side of bus. If the fan cannot be topped, the clutch is good. Next test requires a mechanical temperature gage or an infred temp reading gun. Release the radiator pressure cap. put temp gage pickup into radiator and compare bus gage and the mechanical gage. Notice any difference. If infred gun is available, make a note of temps at several places on engine cooling system, while engine is running. The top of radiator and top hose should indicate the highest temperature. Check the bottom hose and bottom of the radiator. Check for any oil in coolant and any coolant in oil. Being an old guy, I use 180 degree t-stats in all my 7.3 engines, with a 15 pound radiator cap. Frank
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