1991 Chevrolet G Series Van (G30) Q&A
1991 Chevrolet G Series Van (G30) Question: overheating issue , not all the time.
Carpet cleaning van. Cleaning unit is van powered by a driveshaft engaged with an electric clutch. Van drives fine with no temperature issue. When I engage the system it will slowly go to overheat. When the system is engaged the RPMS are ramped up slightly, to about 1800. Flushed system. Replaced fan clutch, thermostat, water pump. Water is circulating well. There are no leaks I can find but I am loosing coolant. After it cool down and I open the radiator cap I've lost a lot of coolant. - Rick pro carpet
Sounds like at this point, you are seeing the result of an air pocket in your cooling system introduced probably when you replaced the thermostat and water pump. Purge the air out, refill the coolant and try again... - DaveJHM