My New (Used) Jeep Cherokee Part VIII

Today, I decided to service the cooling system. This is a task neglected by many, but one that can have an impact in prolonging engine life and/or preventing a major repair. Removing the fuel pump will have to wait as I decided that it was best to fill up the gas tank before the price of gasoline goes up due to Gustav.

After inspecting the radiator and heater hoses and clamps, I headed to the store and purchased antifreeze, a thermostat and a new radiator cap. I also purchase an antifreeze treatment, which will supposedly provide a lubricant for the water pump. By the way, this new antifreeze is supposed to last for five years or 150,000 miles.

Anyway, I got home, parked my car on the driveway, placed a container under the truck and tried to open the drain valve. I couldn’t get my fingers in far enough to turn the valve open, not even after removing the front grill, so I decided to disconnect the lower radiator hose instead. After draining the old fluid, I reconnected the hose, added the flush, filled the radiator with water and ran the engine for about 15 minutes.

After the 15 minutes had passed, I turned the engine off and, carefully, disconnected the lower hose again to drain the radiator. While the system drained, I removed the thermostat housing by first disconnecting the two hoses (radiator and water heater), the temp sensor’s electrical connector and removing the two supporting bolts. I then removed the thermostat from the housing, but not before scraping the old gasket from the sealing surface; leaving the thermostat in placed prevented gasket debris from falling inside the housing. I also cleaned the cover, paying close attention to the sealing surface.

Using a water hose, I introduced water through the thermostat housing, making sure to flush the engine block well. I repeated the same process to the heater core, by injecting water through the hose that I had previously disconnected from the thermostat housing and then flushed the radiator.

Next, I installed the thermostat; making sure it was facing in the right direction. I then applied RTV to both sides of the gasket, placed it onto the cover ensuring the bolt holes holes were aligned, placed the cover over the housing and installed the two supporting bolts. After tightening the bolts, I reconnected the two hoses and the electrical connector.

I followed by reconnecting the bottom hose to the radiator, cleaning the overflow tank and adding the radiator treatment. I poured a gallon of antifreeze on a container followed by a gallon of water; 50/50 mixture. I filled the radiator with the 50/50 mixture, installed the new cap and then filled the overflow tank to the “full” mark. I started my jeep and checked for any evidence of leaks; none were detected.

After putting my tools and equipment away, I took the jeep for a ride just to make sure. So far everything looks great…there are no leaks and the truck is running great and cool. See you next time.