Heater Core/Heater valve

[tylergrant2011]

Hi everyone i have a 1987 Jeep comanche 4.0L. Lately ive noticed a little bit of coolant leaking in the cab of the truck. wondering if its the heater core or something of that nature and what is the best procedure. and also the valve that is close to the core itself is there a way to bypass it by any chance because i notice it leaks some

 

[ehall]

If you have a leak inside it is about 99% odds that the core is leaking

The external valve can be eliminated altogether, or buy a valve for the 2.5L since it is all-metal instead of the plastic crap used in the 4.0L

 

[tylergrant2011]

Can anyone explain the purpose of this valve?

 

[ehall]

In the early models, the heater core in the dashboard is always exposed to the air (hot blows through it, cold blows over it). The valve is used to close off the supply of coolant to the heater core as you move the slider over to the cold position, so that the heater core does not shed as much heat when you are trying to run cold air through the dash. Later models do a better job of isolating the core in the dash, and deleted the valve. You can delete the valve too but it will reduce the effectiveness of your AC a bit, how much will depend on how good your AC works.

 

[cruiser54]

In the early models, the heater core in the dashboard is always exposed to the air (hot blows through it, cold blows over it). The valve is used to close off the supply of coolant to the heater core as you move the slider over to the cold position, so that the heater core does not shed as much heat when you are trying to run cold air through the dash. Later models do a better job of isolating the core in the dash, and deleted the valve. You can delete the valve too but it will reduce the effectiveness of your AC a bit, how much will depend on how good your AC works.

Not at all. I live in Arizona and have eliminated numerous control valves on pre-97 XJs and MJs.

As long as the blend air door cable is adjusted properly, it all works great.

 

[ehall]

I find the AC only works at 100% cold setting where the hot is almost blocked off. As soon as I move it just a tad, it picks up a ton of heat.

 

[cruiser54]

I find the AC only works at 100% cold setting where the hot is almost blocked off. As soon as I move it just a tad, it picks up a ton of heat.

Need to adjust your blend air door then............