Heater control valve .... no heat....

[azscott]

Like this thread has not come up lately...haha!

Living in Phoenix it is a long while before you NEED heat..but I need it now...and I ain't got it. However this does not look to be too comlplicated.

I assume the vacuum actuated valve in the heater lines that sits just above the charcoal cannister is the control valve to let hot water into the heater core. I have hot water up to this vacuum valve but not past it. This is where the T is to go up to the expansion bottle.

I am not sure if the valve is cr@p or the vacuum is not making it to the valve and I guess not as I don't feel any vacuum on the line.

Irregardless though....can the valve just be removed.....and if so what are the downsides. The one I could see is that you would have hot water flowing into the core during summer when you use AC. This is what happens on my Super Duty F-250....ther eis alwyas hot water running in and as such the AC temp is reduced by 25 degrees.

I suppose I could use a ball valve in place of the heater control valve. I could just turn the valve on manually when we hit winter and then shut it off when summer comes..which is April anyway.

I ask this all as I do not have time this week to rip into the dash and see where the vacuum comes from that opens the HCV....if someone knows let me know for future repairs.

I would guess there is yet ANOTHER vacuum leak...I have fixed over a a dozen so far....but until I find it I need to rig heat and at the moment it ain't making it past that valve in the hot coolant lines in the engine.

scott

[Geonovast]

I just removed mine when the plastic part cracked and sprung a leak.

 

They did away with it in 96 or 97 anyway.

 

I hate AC so I wouldn't know if it would adversely affect that or not... I don't imagine it would.

[azscott]

...yah...gotta have AC down here or you will toast. I drove a few days this summer without it when we hit 116....ugghh.

Anyway thanks for the response....I figured it could just be removed permanently anyway.

scott

[azscott]

...well that wasn't it....the HCV is open UNLESS there is vacuum applied and mine was wide open. Seems the heater core was plugged....had to blow it out with the hose and a pile a crud and rust came out. Purged out the water..filled her up with new fluid and now I have heat.

Lucky for once...it was this easy.

scott

[azscott]

...shoulda just removed that stupid HCV. After I blew out the core....I put it all back together....everything was fine.

So I grabbed my wife and we went for a drive. I had just finished replacing the headliner and ripped the interior out....chucked the nasty rug and jewt insulation...liined the whole interior with Damplifier and installed a double foil backed Heat Wave Pro insulation on the floors.....then put in a brandy new textured vinyl floor. Ahhh..smelled like a new truck..looked almost new ( well accpet for the sun rotted dash but I will get there)...

Then...sniff..hmm...smells like coolant burning on my engine....uhhhh....engine temp at 220....poop...1/3 mile from home. Limped on in...with steam pouring out.

Dang HCV literally split in half and dumped most of my coolant.......MAN....I hate filling and bleeding this damn thing :headpop:

Well no serious damage done...now off to rig up a T to eliminate the cracked HCV... 8)

By the way...I forgot I had the Comanche service manual from jeep...I looked up the Heat valave and yep...it is worthless. The only time it is closed is either in vent or with the system off...otherwise it is open. Which makes me wonder if it has a similar effect on the AC as it does in the Ford Diesels....since it is open even with full AC..I wonder if it affects the temp of the AC. I know there is a bypass mod for the Super Duties to close the valve during max AC as it lowers the output air temp by about 20 degrees?

scott