Open systen , heater control valve question

Converting to an open system and looking at the write up it states purchasing a new control valve but can't I just run hose straight through where the old bottle woulda' been ?

http://www.jeepinjoe.com/XJ_Tech/Open_System_Switch/open_system_switch.html

I just took the heater control valve out when I did this. Now I don't have to flush the heater core every winter to get heat.

You wouldn't want to feed that much coolant into an open system overflow bottle. The radiator only sucks in coolant from the overflow bottle when it cools down. Your overflow bottle would overflow quickly. (Which, in spite of it's name, it should not do.) Best way is like miannicca said - eliminate the valve and just run the straight hoses straight from the tstat housing and water pump to the heater core. Newer vehicles don't have a heater valve and you don't need one.

winterbeater said:

Newer vehicles don't have a heater valve and you don't need one.

Click to expand...

x2 I think it was 97 when they did away with the heater valve in the XJ.

You don't necessarily need a heater control valve (as said) but if you're going to eliminate it you need to run the heater hoses straight thru the core. You can't use the old bottle as an "overflow". Just get a generic overflow bottle and run the small hose from the radiator fill neck to the new overflow. You can put the generic bottle where the old one WAS or find a different location.

By open, I assume you mean a radiator with a cap and you're ditching the crappy football. Yes, just run those two lines straight to the heater core. Cap off the vac line that used to go to the heater control valve.

You may have to "pre-stretch" one of the lines or use an adapter as one of the heater core nipples is 2/4" versus 5/6". I just hammered a socket into the heater hose to stretch it a bit beforehand and it slipped on nicely.

Careful getting the old hoses off. Use a razor and slice along the length and peel the rest off. Now's a good time to flush the core back-n-forth with the garden hose to get all the crap out. Just aim the hose in there as you don't really want full hose pressure on the core to avoid causing leaks.

Be careful with that razor, though. You don't want to create a leak path by scoring the nipple.

So I finished the job, went thru the heater core and got rid of all the crap hoses. The thing was super clogged, no wondering my hearter sucked. Been flushing it , heating it up and all seems to be holding well without overheating.

Thanks Paulhead, I think I am going to do this on both my XJ's :yelclap:

John

Now you have the option also, if it starts to overheat, open the windows and crank up the heat. It's an extra heat exchanger.

Been driving it around all day, runs great. Can't believe how hot my heater gets, coulda' used it a couple months ago.