Jeep® Closed Cooling System Maintenance

The closed cooling system is produced by using internal pressure and a water pump. This pressure is created in the uneffient plastic bottle on the firewall passenger side. In order to get the best performance out of this system, we will assume the position that you have just drained your cooling system.

Important Note: This should be done after ensuring all you hoses and hose clamps are in good condition and no coolant leaks are currently occuring or present.

Procedure:

1. With you cooling system already emptied and washed out, lets start filling her back up till the coolant rises half way up the pressure bottle.



2. Replace the rubber seal on the pressure cap of the pressure bottle and warm up your vehicle until you can hear coolant flowing through the hoses.



3. I suggest you take a break and let the engine cool down before you remove the air in the system.
4. With the engine cool, unscrew the coolant temperature sensor until the coolant starts to poor out. Wait about 3 seconds (approx) then screw the sensor back in.



5. Now with most of the air out of the system, fill the pressure bottle to the top with more coolant or until coolant spills over the rim.



6. Replace the cap, and turn over the engine. The cap should start to leak some coolant which is perfectly fine. The closed system is just pressuring its self.



7. If the coolant does not escape through the bottle cap, turn off the engine and let it cool down before adding more coolant. Tighten down the cap and try again.



8. You cooling system should be pressurized and ready to perform like an open system.

Submitted by: XJoshua