HVAC issues
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Joined: Feb 2018
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HVAC issues
I have a 1985 with manual climate controls NOT the automatic controls.
The A/C and the heater blows through all vents and I cant tell that it changes at all. I know for sure that it always blows through the dash vents. There is nothing wrong with the vacuum check valve on the intake.
I took the climate control panel out of the dash and have vacuum there but when the vacuum lines are connected to the panel it sounds like there is a leak. When the lines are unplugged the leak sound goes away. The leak changes sounds when you change functions but it's still there. I have never heard of a vacuum leak here nor do I know what to do to fix it. I pushed the little block onto the panel the best I could but there is still leak.
Can I buy a new clear block and plug the lines into it. Maybe get rubber hoes and go without the clear block (I dont want to do it but if I have to, then so be it). Thanks for any help.
The A/C and the heater blows through all vents and I cant tell that it changes at all. I know for sure that it always blows through the dash vents. There is nothing wrong with the vacuum check valve on the intake.
I took the climate control panel out of the dash and have vacuum there but when the vacuum lines are connected to the panel it sounds like there is a leak. When the lines are unplugged the leak sound goes away. The leak changes sounds when you change functions but it's still there. I have never heard of a vacuum leak here nor do I know what to do to fix it. I pushed the little block onto the panel the best I could but there is still leak.
Can I buy a new clear block and plug the lines into it. Maybe get rubber hoes and go without the clear block (I dont want to do it but if I have to, then so be it). Thanks for any help.
Pro
Joined: Jun 2018
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From: Louisville, Ky
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My 85 Z51 was doing the same thing. The vacuum reservoir under the hood by the evap canister at the left headlight is missing. Shop simply plugged the single line that should have been connected to the reservoir and now the door changes air flow. I do need to get a reservoir though. HTH.
Drifting
Joined: Mar 2013
Posts: 1,952
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From: Venice Cali.
You all need the vacuum ball ,it hold vacuum when the car is not producing it. If you try to unplug it you can't imagine how much power it has.Just replace any broken otr loose lines. ONE at a time!
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I went out and unplugged the line going to the vacuum ball then plugged the line but no change. I thought you guys may be right since my cruise control stopped working around the same time. One thing I noticed is when vacuum is absent from the HVAC it doest not go to defrost only like it should. It's almost like the door for the dash vents is stuck open but I can get it to move manually.
Pro
Joined: Jun 2018
Posts: 657
Likes: 239
From: Louisville, Ky
2022 C4 of the Year Finalist - Unmodified
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C4 of Year Finalist (appearance mods) 2019
I went out and unplugged the line going to the vacuum ball then plugged the line but no change. I thought you guys may be right since my cruise control stopped working around the same time. One thing I noticed is when vacuum is absent from the HVAC it doest not go to defrost only like it should. It's almost like the door for the dash vents is stuck open but I can get it to move manually.
controls
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Joined: Feb 2018
Posts: 86
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Ok I just noticed you have a leak at the controls. Is the leak coming from where the hoses connect to the lever that you move to select the mode you want. If so you need that vacuum control. It's the white one in this picture.
controls
controls
Pro
Joined: Jun 2018
Posts: 657
Likes: 239
From: Louisville, Ky
2022 C4 of the Year Finalist - Unmodified
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Might be able to do something if there is a part number. All my searching only came up with some complete units on ebay $300 to $39 just search 85 corvette climate control.
Last edited by Joe K; Jan 23, 2019 at 04:03 PM.
Melting Slicks
Joined: Oct 2016
Posts: 2,024
Likes: 363
From: Central Alabama
It's been many years since I needed one but you used to be able to buy those separately. Had an airman that worked for me have one fail. We picked one up at the LPS for his Pontiac.Back in the 80s they were under 10 bucks.
I think the part number was 16040637 for an 85 corvette
item 2 here 85 C60 control IPB
I think the part number was 16040637 for an 85 corvette
item 2 here 85 C60 control IPB
Last edited by belairbrian; Jan 23, 2019 at 08:36 PM.
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