Closed to open ooling system conversion

I have most of the parts on hand now... if the new open-type radiator, balancer pulley & lower hose shows up tomorrow, it's awn for saturday morning.

I got a coolant catch bottle from Summit, but it doesn't have a siphon hose...just a port on top and a drain cock on the bottom. I 'think I can cobble something together, but does everything have to be airtight for the coolant to return back to the radiator?

I swear I've seen plastic bottles (LOL a Prestone jug with hole in the cap) used as recovery tanks, but I'd prefer not to be that butch.

Where does the factory catch tank go on an HO motor Jeep? (pics please) If it works with what I have going on under the hood, I might swing by the boneyard for one.

TIA
Woody

Catch tank does not have to be air-tight. The bottom is the connection to the radiator neck, the top is just a vent to atmosphere. Look at the radiator cap. On the bottom, there's a small metal disc beneath the rubber gasket, and that disc seems sort of loose and floppy. Under pressure, the disc is pushed against the rubber and makes a seal. As the system cools down and creates a vacuum, the disc pulls away from the rubber and allows the coolant to be siphoned back into the radiator from the catch tank.

Aha! I've been around closed systems too long...

BTW where does the OEM HO tank sit?

Make sure the hose you use between the radiator neck and the overflow bottle can hold the vacuum. I'm a lab guy so I used my chemical, temperature resistant tygon tubing. It's too soft to stay open when a vacuum is applied. I'm not sure where the bottle goes in the 91-96 XJs. I bought a factory one, and just have it sitting in the area the closed system bottle was, I think that is the general vicinity from the factory. It catches any fluid, but it doesn't feed it back when it cools off due to the tube collapsing.
HTH

Fred

woody said:

Aha! I've been around closed systems too long...

BTW where does the OEM HO tank sit?

Click to expand...

Right behind the battery