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Unread 10-13-2009, 10:09 AM   #1
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1999 XJ Cherokee 
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upgrading a closed loop coolant system

im looking to buy an 89 2 door, with the closed system. the coolant system needs some work anyway, and while im in there i was thinking of going to an open style. as far as i understand this, it should be as easy as ditching the radiator and pressure bottle, then putting in a newer style radiator with a cap that has the correct pressure. anything im missing? recommendations for a good radiator? thanks for the help.

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Unread 10-13-2009, 10:30 AM   #2
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If you swap out the radiator, you will also need a coolant overflow bottle, a newer style ('92+ I think) heater control valve for the new piping, and will need to address the coolant temperature sensor (your sensor is currently in the radiator, where as the open systems use a different type sensor in the thermostat housing). Check the FAQ sticky... there are sever comprehensive articles on how to do this.

There are actually easier ways to to that as well that don't require all the new hardware (its all in the FAQ).
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Unread 10-13-2009, 05:36 PM   #3
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I chose to do this swap with all new components. I covered it in this thread (with photos on the last page): http://www.jeepforum.com/forum/f11/p...estion-834546/

There are a number of threads and other webpages with good advice on how to do this. Use the search function! And yes, as TheNerd said, you can use your existing system with a few mods, but I chose to start from scratch since all my components were pretty old and beat up.
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Unread 10-13-2009, 05:49 PM   #4
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The bad rap that the closed system gets is almost entirely the fault of the failure-prone pressure bottle. Unless you actually need a new radiator, I would suggest that you consider a metal pressure tank. I put one on my '88 a couple of years ago and have had no problem since.
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