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Heater control valve question

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by sysmex, May 21, 2009.

  1. sysmex

    sysmex New Member

    Well just had my A.C. recharged for the summer. A.C shop told me that my heater control valve is bad due to hot hoses going past the valve to the heater core. Well I just replaced the control valve and same thing happens. If I pull off the hose at the valve there is no vacuum on the hose with the AC on. If I turn the heater on still no vacuum at the hose. I suspect that valve on the other end of the hose is bad. Does anyone know what it is called? Can it be bought at a parts store?

    Currently I have staight manifold vacuum going to the valve and the hoses are now cool. I suspect that heat off=vacuum
    heat on= no vacuum.

    Opps almost forgot this is a 1999 K1500 dual A.C
  2. sysmex

    sysmex New Member

    Just keeping this thread alive, Anybody know this valves name?
  3. GaryL

    GaryL Epic Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    I'll do a little looking and see what I can find out.
  4. GaryL

    GaryL Epic Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    I couldn't find anything, but I went and checked my Suburban. I did not have any vacuum on that line either and my hoses were hot. My A/C works fine, so I'll probably just leave it alone. I kind of like the fact that water is constantly flowing thru the heater core, it gives it less of a chance of gunk building up in there.
  5. sysmex

    sysmex New Member

    I see your point if it's not broke don't fix it. I unfortunately like to fiddle with things. It just bothers me that that the heater core is hot when I don't need it to be. I would imagine that some of that heat migrates past the shutter door into the evaporator section. Down here in Florida every little bit helps with the A.C.

    On another note. Do you think that valve is a Open / closed function or variable?
  6. GaryL

    GaryL Epic Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    It is either opened or closed. It uses the blend door in the cabin to control the temp. Let me know what you come up with for a solution.

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