Medium and Heavy Trucks
Have Truck Repair Questions? Ask an Expert
Have you ran a combustion gas test at the radiator? Where you suck the gases off the top of the radiator through the liquid and if the liquid changes color , you have combustion gases entering the cooling system from a cracked head or head gasket. Most large auto supplys carry the tester and rent them.
Any overheating? Does it start as soon as engine is started? If you put pressure tester on the radiator does pressure continue to climb past 14 lbs.
Compressor air pressure ?
Site , not me, I rather continue via web. You already changed the compressor and no change. I see no other connection between the air system and the cooling system other than the compressor hoses. Have you removed the compreesor cooling hoses and plugged them for a short test>