HVAC controls

D

Dean The ResourcefulNorse

Member
Mar 25, 2020
108
0
16
OK Wizards;

I know someone can help me with this issue. It may get your attention off of
crimps and solder (zzzz) for a while. My heater valve (in the hose upfront)
has vacuum to it all the time. Can't really tell if it is more or less with
the control set to heater or off. On a previous '73-23',40 years ago
(really) I researched it and removed the vacuum valve and replaced it with a
ball valve so I could optimize the AC by eliminating any hot water going
through the core. First question is there an easy repair to the control unit
to actually turn on and off the various valves; 2nd question is there any
valves that really work; and 3rd question do you see any problems with
throwing that heater valve away and putting in a ball valve?

Thanks

Dean Hanson 75 Avion- up and raising.
 
All of those vacuum controlled hose valve pretty much do not travel a full
90°, as you have already figured out. So, if the cables are adjusted to
completely close off the water flow, then you are unable to to achieve full
flow. So in summer, some hot water circulates through the heater core, and
the ac has to get rid of that heat, too.
A new valve will just fix the leaky old vacuum diaphram, and not stop
the water flow.
Many coach owners install a manual shut off valve, and switch it
summer and winter.
I just disconnected the vacuum linkage from my valve, and used a zip
tie to open it all the way for winter, or close it for summer. A 5 minute
fix. No valve swapping necessary.
Jim Hupy
Salem, Oregon

On Tue, Mar 31, 2020, 4:29 PM Hanson Email via Gmclist <

> OK Wizards;
>
> I know someone can help me with this issue. It may get your attention off
> of
> crimps and solder (zzzz) for a while. My heater valve (in the hose upfront)
> has vacuum to it all the time. Can't really tell if it is more or less with
> the control set to heater or off. On a previous '73-23',40 years ago
> (really) I researched it and removed the vacuum valve and replaced it with
> a
> ball valve so I could optimize the AC by eliminating any hot water going
> through the core. First question is there an easy repair to the control
> unit
> to actually turn on and off the various valves; 2nd question is there any
> valves that really work; and 3rd question do you see any problems with
> throwing that heater valve away and putting in a ball valve?
>
> Thanks
>
> Dean Hanson 75 Avion- up and raising.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
OK Wizards;

I know someone can help me with this issue. It may get your attention off of
crimps and solder (zzzz) for a while. My heater valve (in the hose upfront)
has vacuum to it all the time. Can't really tell if it is more or less with
the control set to heater or off. On a previous '73-23',40 years ago
(really) I researched it and removed the vacuum valve and replaced it with a
ball valve so I could optimize the AC by eliminating any hot water going
through the core. First question is there an easy repair to the control unit
to actually turn on and off the various valves; 2nd question is there any
valves that really work; and 3rd question do you see any problems with
throwing that heater valve away and putting in a ball valve?

Thanks

Dean Hanson 75 Avion- up and raising.
==================
 
Perhaps inspect the wafer in the control valve and put a light film of plumbers lube on the smooth contact surface. You can take water valve out of
hoses snd see if it's working as a test. Theoretically they weep a bit when off so some fresh coolant circulates to the core to replace additive
package in the high corrosion areas. . Mine on my 77 works. I like that because in spring and fall it's usually heat in the AM and AC once sun is up
and I want control at dash. No vacuum should be On and vacuum should be Off.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
Dean,

I can't give you any direct answers, but this link will show you a color
coded version of the vacuum diagram. It may help you to figure out the
problem and get the system working.:
http://www.gmcmhphotos.com/photos/color-hvac-troubleshooting-charts/p22990-hvac-diagram-color-comp.html

As far as the added ball valve, I have one on my '76 and think it helps in
the summer.

Good luck -- you CAN fix it.

Ken H.

On Tue, Mar 31, 2020 at 7:29 PM Hanson Email via Gmclist <

> OK Wizards;
>
> I know someone can help me with this issue. It may get your attention off
> of
> crimps and solder (zzzz) for a while. My heater valve (in the hose upfront)
> has vacuum to it all the time. Can't really tell if it is more or less with
> the control set to heater or off. On a previous '73-23',40 years ago
> (really) I researched it and removed the vacuum valve and replaced it with
> a
> ball valve so I could optimize the AC by eliminating any hot water going
> through the core. First question is there an easy repair to the control
> unit
> to actually turn on and off the various valves; 2nd question is there any
> valves that really work; and 3rd question do you see any problems with
> throwing that heater valve away and putting in a ball valve?
>
> Thanks
>
> Dean Hanson 75 Avion- up and raising.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Yo cannot get replacement discs for the main control valve. Over time, 40+ years, the rubber disc dries out and it leaks. You can take out the disc and take a flat piece of glass with a piece of #400 or 600 wet or dry sandpaper on the glass and rub the disc on the sand paper with water to remove some of the dried surface. When you resemble the valve it should seal better and give more vacuum to the various actuators.

I have used a ball valve on the heater hose for several years.

Emery Stora
77 Kingsley
Frederick, CO

>
> OK Wizards;
>
> I know someone can help me with this issue. It may get your attention off of
> crimps and solder (zzzz) for a while. My heater valve (in the hose upfront)
> has vacuum to it all the time. Can't really tell if it is more or less with
> the control set to heater or off. On a previous '73-23',40 years ago
> (really) I researched it and removed the vacuum valve and replaced it with a
> ball valve so I could optimize the AC by eliminating any hot water going
> through the core. First question is there an easy repair to the control unit
> to actually turn on and off the various valves; 2nd question is there any
> valves that really work; and 3rd question do you see any problems with
> throwing that heater valve away and putting in a ball valve?
>
> Thanks
>
> Dean Hanson 75 Avion- up and raising.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
After trying the sandpaper it did help some but I was still having issues getting enough vacuum to each position when needed. I had a suggestion from
another GMCer to change the center clip of the disc assembly to a small bolt and lock nut to put more pressure on the sealing surface and it worked
much better.
--
C. Boyd
76 Crestmont
East Tennessee
 
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