I have a '89 XJ, 4.0/Automatic. I want to do the upgrade to an open cooling system. I searched, but can't seem to find a clear set of instructions and list of parts for the upgrade. Any help would be appreciated. Thanks!

 

radiator froma 91 up xj relocate pressure bottle to a lower point so you dont get air bubbles i think thats about it

 

I recall reading that you don't have to replace the radiator. Just the cap and add an overflow tank. IIRC the cap you need is from a Durango, not sure of the year though...

 

Found it

https://www.cherokeeforum.com/f67/bu...pgrades-84020/

3.You can convert the closed system to open without replacing your radiator by using the fill cap from a 4.7 durango or dakota, cutting it into your upper hose, and replace your bottle with an MJ overflow tank or any that fit. Then cap off or eliminate the T'ed lines in the heater core.

 

I don't think u want move the bottle lower as any air in the system will seek the highest point. U MUST convert the old bottle from being pressurized to non-pressurized (vent thru cap/open to the atmosphere, open system) AND the bottle MUST fill/empty from the bottom. Small tube from below rad cap is plumbed to the bottom of the bottle.

 

Good to know. Thanks for chiming in with correct info.

 

Awesome. Thanks everyone. I'm just not quite clear on what I need to do with the T'ed lines. I don't want to kill my heater.