Vacuum water valve

Anyway, back to the purpose of this posting, I have been playing around with the vacuum system under the dash identifying leaks and fixing those. I think I have it licked except for one thing. On the control module in the dash there is a diaphragm switch with two vacuum hoses coming out of it. When engaged (the heat lever pushed to heat) vacuum goes through the system. And it holds vacuum, but because there is vacuum with the heat on that should mean that the water valve would have to be pulled open. When the heat lever is in the off position I have a vacuum leak. So, does this affect the use of the entire vacuum system? I cant imagine it being good for my idle either even if the small hose only pulls a small amount on the manifold.
So, should there be no leaks in the control module no matter what place the heat lever is in? I have three of these modules and they all leak differently at the diaphragm.
Plus, I think I'm going to have to pull the water valve off and pour water through it to see what position it is off in, just to make sure.
Lastly, I HATE THE FIDDLY STUFF ON THESE CARS! :soapbox::mob::elmer:
 
Life really was better in the old days.

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There is a bleed in the vacuum line, so if I'm understanding you and the FSM right, it wouldn't hold a vacuum when it's off.

There is a test procedure in the FSM. I'd go through that step by step and see if it makes sense.
 
So I put it all back together and took the car for a drive, but I decided to put the lever for heat to full on and see what happens. Well after driving for about ten minutes the air coming out of the vents was still cold. Then I turned the lever to the off position and it went hot. No, you can't get the vacuum hoses reversed on the control assy because you have a large hose and a small hose, they only go on one way. Now here's the thing, I decided to turn the heat back off again by switching the lever back to full heat, the air blowing stayed hot for the rest of the trip.
This drives me nuts, I am going to check a water valve I have here and look it over, once I have decided if it can be made to work out not I may just go ahead and convert the lever mechanism to a cable unit and be done with it.
 
I have stock manual valve from a 75Bbody. Needs a good cleaning but works perfectly. Asking $20cad + ship

http://www.kijiji.ca/v-view-details.html?requestSource=b&adId=1082666099

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Thanks for the offer, I haven't seen one of these before but i was going to try another vacuum unit I have spare before converting to a manual unit, the one below I figured would be worth a shot.
1X Heater Control Valve C3UZ18495A YG133 For FORD E & F SERIES BRONCO DODGE VAN
 
the original crackpot valves work somewhat smoother. But we all know they are not cheap and probably won't hold forever.
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Turns out there is a leak in my 1971 Monaco's cooling system (440 with H51 A/C), which seems to come from the HCV (photo attached below). @Big_John and @ceebuddy (and whoever else would like to chime in), would you recommend replacement with NOS (which is expensive) or would a used one be worth a shot if found at the right price (I have traced one coming from a parts car)? Or is sthg else worth checking out first, before replacing the valve?

Monaco heater control valve 20190210_103358.jpg
 
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The only heater valve used in the C bodies with a/c, but without Autotemp 1, was the vacuum one like you have shown above in your Monaco. But it was too cheaply built and the bakelite used in the can and inlet/outlet nipples would both crack after about 2 years of use. Some people lost engines because of this thrifting by Chrysler. So if you want reliability, I would use the aftermarket metal ones shown earlier or if you want original at all costs, then use the now expensive (that because supply is running out) original bakelite ones.

Also, there were not two different types of heater control valves in these cars when produced by Chrysler unless you had auto temp 1 on them with a/c. Then the only valve used was the one shown in a post previously:

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This other type of valve had a built in control to open up the vacuum control when the engine heated up before allowing the Autotemp 1 system to begin working. It is not like the aftermarket metal one mentioned above in that respect.

And on C bodies in these years with no a/c, there was no heater valve, at least on the very few that I have seen.

Between these cheap heater control valves combined with their radiators with no cooling margin even when new, the manager of the cooling systems laboratory must have surely been promoted for all the cost savings he squeezed out of every cooling system Chrysler built in the 70s. Which is one of the reasons Chrysler lost a bunch of customers out West at least in the 70s. Really stupid to promote guys that made impressive cost reductions in the product without looking at the implications in production - and it led to bankruptcy circa 1981 when other managers took note and followed accordingly in their departments. I was there to witness it all go down.
 
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The only heater valve used in the C bodies with a/c, but without Autotemp 1, was the vacuum one like you have shown above in your Monaco. But it was too cheaply built and the bakelite used in the can and inlet/outlet nipples would both crack after about 2 years of use. Some people lost engines because of this thrifting by Chrysler. So if you want reliability, I would use the aftermarket metal ones shown earlier or if you want original at all costs, then use the now expensive (that because supply is running out) original bakelite ones.

Thanks a lot for this information, @saforwardlook . Several questions:

1. did the folks who lost their engines, lose it because they did not realize they'd lost all of their coolant and massively overheated?

2. Attached is the photo of a used one on a '69 parts car (Monaco wagon). I think that I see a discoloration as on mine -- mine is wet, this one seems dry, but the areas with discolorations are to my eyes eerily similar. Thoughts? I was thinking of using this unit (or another one from another parts car), but you suggest that a new one (either NOS or replacement) might be a better idea -- did I understand correctly?

3. If I go non-OEM, which all-metal aftermarket one have you bought for/installed on your cars that you would recommend? I have found the following:

NOS, $150 (I have seen some cheaper ones, this is for illustration): NOS Mopar Heater Control Valve 1969-71 B & C Body W/ A/C - Hiltop Auto Parts
non-original, $95: NORS Mopar Heater Control Valve 1969-71 B & C Body W/ A/C - Hiltop Auto Parts

Look forward to your further replies.

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Thanks a lot for this information, @saforwardlook . Several questions:

1. did the folks who lost their engines, lose it because they did not realize they'd lost all of their coolant and massively overheated?

2. Attached is the photo of a used one on a '69 parts car (Monaco wagon). I think that I see a discoloration as on mine -- mine is wet, this one seems dry, but the areas with discolorations are to my eyes eerily similar. Thoughts? I was thinking of using this unit (or another one from another parts car), but you suggest that a new one (either NOS or replacement) might be a better idea -- did I understand correctly?

3. If I go non-OEM, which all-metal aftermarket one have you bought for/installed on your cars that you would recommend? I have found the following:

NOS, $150 (I have seen some cheaper ones, this is for illustration): NOS Mopar Heater Control Valve 1969-71 B & C Body W/ A/C - Hiltop Auto Parts
non-original, $95: NORS Mopar Heater Control Valve 1969-71 B & C Body W/ A/C - Hiltop Auto Parts

Look forward to your further replies.

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Answers to your questions Michel are below:

1. Yes, these valves leak slowly at first and there is usually no indication of coolant loss due to steam visible from under the hood, and if people don't watch their temperature gauges or lights they can overheat their engines pretty easily. When a hose goes it is usually pretty visible quickly. Leaking radiators and freeze plugs can also be subtle during the initial stages too.

2. I definitely would not use a used one. They won't last long before needing replacement, guaranteed.

3. You can get NOS ones cheaper than $150 off of ebay. Here is one example: 1969 1971 CHRYSLER B BODY VINTAGE HEATER VALVE 4 PORTS NEW | eBay

But if you want long life, then the metal ones are best and prices vary on those too. The one you show is just a reproduction one, not original Chrysler like the listing seems to imply.

Here is an example of a cheaper one: Everco H1949 Heater Valve For Various 69-79 Chrysler Dodge Plymouth W/ A/c | eBay
 
The manual shut off valves posted earlier are from early 70's dodge pick up trucks....Part # 84706

Advance Auto Parts - Down for Maintenance

I have two of these on the heater lines on my 84 Dodge W350 crewcab cummins conversion. I also used a heater control valve, vacuum operated, from a 90's ford Ranger that works perfectly since I could not find a replacement for the OEM dodge piece.
 
@saforwardlook, I grabbed the correct-look, teapot-like HCV to which you’d linked. Thank you for this info!

Now, if I understood you correctly, the Everco H1949 would have a period look but be much more reliable than the correct part, I.e., than the “teapot” HCV (part number 2936 490). Since my Monaco is meant to be a reliable driver to various shows, my thinking is to keep the part I bought as a “correct spare” ( in case supplies disappear or get crazy price-wise) and to get one of the Evercos.

That ought to work and be reliable for quite a few years, right? I understand there are always some risks, but is there any reason to think there “should” (as opposed to “might”) be any aging issue with those “all metal” ones?
 
@saforwardlook, I grabbed the correct-look, teapot-like HCV to which you’d linked. Thank you for this info!

Now, if I understood you correctly, the Everco H1949 would have a period look but be much more reliable than the correct part, I.e., than the “teapot” HCV (part number 2936 490). Since my Monaco is meant to be a reliable driver to various shows, my thinking is to keep the part I bought as a “correct spare” ( in case supplies disappear or get crazy price-wise) and to get one of the Evercos.

That ought to work and be reliable for quite a few years, right? I understand there are always some risks, but is there any reason to think there “should” (as opposed to “might”) be any aging issue with those “all metal” ones?

I think you have the realities as I see them correct. I too only put the factory ones on cars I don't drive that much, which is most of mine. But for the few that I do drive more frequently, I use the Everco metal type ones. Keep clean antifreeze in the cooling systems and you should be just fine for many years. Corrosion in cooling systems and debris is what makes even the metal ones deteriorate and stop working (closing/opening) as opposed to leaking.

You should be fine with what you are going to do.
 
Thanks again to all, and especially to @saforwardlook, for all the suggestions. I found this morning another thread on the same HCV for 1970 Polara (which I believe is the same), and have linked that thread to this one for future readers.

Short story: I bought both a NOS one with the view of Medina's future thorough restoration (thanks to Steve, I found one at a very good asking price, so I am stocking up) and I decided to install, for the time being, the Everco all-metal replacement HCV because reliable operation is my main consideration for the foreseeable future -- and I want to be able to take Medina long-distance during that time.

I bought the Everco H1949 from the link sent by Steve; it arrived promptly and Wyatt has already installed it. It bolts right in, following the instructions on the box (posted below, in case this is helpful to someone -- for C-bodies, it is important to re-use the old bracket).

Everco HCV properly installed 20190216_162202.jpg


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