Closed to open cooling system.

[tugboat95]

So after trolling thru here and other Jeep sites I could not find out how or where to mount the overflow tank. Every video on YouTube ends with, "I'll figure out where to put this later." All the posts, videos etc say buy the tank Dorman 603-305. DO NOT BUY THIS tank. It won't fit anywhere on a Renix with the open Relay center. That is for a later year 4.0 with a redesigned relay center and OBD diagnostics.
 
DO BUY Dorman 54002 engine coolant recovery tank. It's universal. It's snug but it fits where the original pressure tank was located.
 
Remove old tank, bracket and the vacuum switch (cap vacuum line). Route the heater hoses as seen. You will need adapters to make the 2 sizes fit. 5/8 to 3/4.
 
I made a bracket out of a piece of aluminum angle. 1 inch. Then I drilled 2 holes in the pinch weld at the top of the firewall. Bolted the angle to the pinch weld. Then I drilled 2 more holes in the Aluminum and bolted the tank bracket to it.
 
I routed the hose across the back of the engine bay from the tank to the radiator cap overflow.
 
You will have to get a little creative on the tank bracket. I had to open the bolt holes a bit and slightly bend them to fit the tank in the hole. You will also need to massage the wiring harness up and forward just a bit.
 
I kept the Aluminum angle a little long for any future mounting of anything....lights????
 
I hope this helps anybody else with this modification. And FYI, the electric fan is now manually operated with a wiring harness and relay provided by K Suspensions.
 
89 Comanche
Eliminator
2wd
4.0L
5 speed PukeGoat
Factory Original
 
 
 

[PIKE]

Looks' nice what you did. You must not have seen any of my posts. The 2.5 EXPANSION tank bolts right in. The holes are already there. You have to relocate a few things but that's no big deal, especially if you have eliminated the EGR.

The MACs tank allows you to go from closed to open.

Mishimoto radiator has filler neck like yours in the picture, but also has threaded insert for 89 electric fan. With that radiator you can eliminate pressure tank , use 2.5 expansion tank and have sensor for electric fan. 

I have the macs tank set up now but if i ever need a new radiator i will get the Mishimoto and eliminate the Macs tank with later years heater hoses.

 

Hope this helps

[tugboat95]

Yeah I found that radiator literally the night I installed the Spectre I have. But By then I was committed as I had bought all the parts.

89 Comanche
Eliminator
2wd
4.0L
5 speed PukeGoat
Factory Original