Eliminating/upgrading the heater control valve w/ A/C

Discussion in 'Technical' started by mercgt73, May 28, 2015.

  1. mercgt73

    mercgt73 Member

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    Has anyone with factory A/C eliminated the heater control valve? It is supposed to stop the flow of hot coolant to the heater core when the temperature control is moved to full cool. If anyone has eliminated it, do you notice a change in A/C performance? Also, has anyone upgraded it to a newer, single vacuum port design?
     
  2. mojo

    mojo "Everett"- Senior Citizen Supporting Member

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    What is meant by "single port design"? How wud u accomplish this and what, if any, advantage to this?
     
  3. 71gold

    71gold Frank Cooper Supporting Member

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    mine is the ...new style single port valve...normanly open.
    you can also put an in hose cutoff to stop the hot water flow in the summer time. my A/C guy put one on my car when he was addressing a no cool situation. he was checking to see if the heater control valve was sutting off the flow...:thumbs2:
     
  4. Krazy Comet

    Krazy Comet Tom

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    With minimal insulation inside the plenum, I suspect the A/C performance would be noticeably degraded without the valve... I plan on using one of the small inline type on mine...
     
  5. mercgt73

    mercgt73 Member

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    Single vacuum port means that the valve is normally fully open and then fully closes when vacuum is applied. The original valve has a partially open position and a fully open position, which uses two different vacuum lines.
     
  6. mercgt73

    mercgt73 Member

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    I thought I remembered a thread you posted. I found it after I asked the question. So you have had no problems with the newer style, Frank?


    That was my thinking also. I am just going to eliminate the brown stripe "partial vacuum" line and use the green stripe "full vacuum" line from the vacuum switch to a new style single vacuum port valve.
    [​IMG]
     
  7. mercgt73

    mercgt73 Member

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  8. Krazy Comet

    Krazy Comet Tom

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    I believe the biggest worry is finding a control assembly that holds vacuum...
     
  9. mercgt73

    mercgt73 Member

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    Krazy Comet likes this.
  10. Krazy Comet

    Krazy Comet Tom

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    Good to know!!! I'm yet to research A/C parts...
     
  11. 71gold

    71gold Frank Cooper Supporting Member

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    mine just had...one hose in and one hose out...
     

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  12. jasonwthompson

    jasonwthompson Member

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    These look like the one from my 70 Mustang, which I think was used from 69 - 73. You can get them for around $40.
     
  13. MonstrousMav72

    MonstrousMav72 Member

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    What is the heater control valve used for? In laments terms. I’m just wondering if I need it because my car runs very hot after a new radiator. Water pump and thermostat.
     
  14. 71gold

    71gold Frank Cooper Supporting Member

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    it controls the hot water flow through the heater box when A/C is on.
     
  15. MonstrousMav72

    MonstrousMav72 Member

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    Okay so to be clear because my car HAD an ac unit which I don’t really intend on reinstalling one, I wouldn’t really need the control valve and just reroute the heater hoses?
     

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