Closed to open radiator cooling stystem
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 98
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Model: Cherokee
Closed to open radiator cooling stystem
I'm a rookie xj owner and I need your help!
I am trying to convert my 1989 closed cooling system to an open cooling system. If you have done this before can you give me some advice.
I switched out the to main heater hoses that go to the cab with the 3/4 and 5/8 hoses and adapters. Then I got a 5/16 fuel line for my overflow hose . I couldn't find a real good place for my coolant reservoir so I made some brackets and made it fit.
Then I filled up the radiator with 50/50 coolant and water
I started to run the engine for a bit (15 min) while revving it generously. My temperature gauge never went on and neither did my electric fan.
Plus nothing came out of the overflow hose at all.
I don't know if this is a good sign or a bad sign?
Also does my overflow hose have to much upward curve to push the coolant out??
(Small hose going along electric fan and to container Is the overflow hose)
(The two newer looking hoses or the two heater hoses)
THANKYOU!
I am trying to convert my 1989 closed cooling system to an open cooling system. If you have done this before can you give me some advice.
I switched out the to main heater hoses that go to the cab with the 3/4 and 5/8 hoses and adapters. Then I got a 5/16 fuel line for my overflow hose . I couldn't find a real good place for my coolant reservoir so I made some brackets and made it fit.
Then I filled up the radiator with 50/50 coolant and water
I started to run the engine for a bit (15 min) while revving it generously. My temperature gauge never went on and neither did my electric fan.
Plus nothing came out of the overflow hose at all.
I don't know if this is a good sign or a bad sign?
Also does my overflow hose have to much upward curve to push the coolant out??
(Small hose going along electric fan and to container Is the overflow hose)
(The two newer looking hoses or the two heater hoses)
THANKYOU!
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CF Veteran
Joined: Jan 2012
Posts: 1,130
Likes: 0
From: Ramona ca
Year: 1990
Model: Cherokee
Engine: 4.0
Did your rad have a place for a fan temp switch on it ? Mine did I just plugged it in and it works fine. If it didn't they you need the newere thermo housing and switch
Senior Member
Joined: Mar 2013
Posts: 691
Likes: 2
From: Texas
Year: 1993
Model: Cherokee
Engine: 4.0L
AFAIK there never was an e-fan switch in the thermo housing? Fan on "91+ is controlled by the PCM. Renix has the switch in the rad.
OP, why are you going to the open system if you were having no problems?
Did you change out the radiator cap?
Why did you expect that the rad would overflow and system overheat while idling after fill up?
Was your temp gauge working before the "conversion"?
OP, why are you going to the open system if you were having no problems?
Did you change out the radiator cap?
Why did you expect that the rad would overflow and system overheat while idling after fill up?
Was your temp gauge working before the "conversion"?
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 98
Likes: 0
Model: Cherokee
AFAIK there never was an e-fan switch in the thermo housing? Fan on "91+ is controlled by the PCM. Renix has the switch in the rad. OP, why are you going to the open system if you were having no problems? Did you change out the radiator cap? Why did you expect that the rad would overflow and system overheat while idling after fill up? Was your temp gauge working before the "conversion"?
The radiator cap seems good.
I was trying to overheat it by revving it and blocking off most of the airflow to make sure the electric fan would turn on.
Temperature gauge is working.
