A/C Experts. Odd Situation...

[turbo39151]

Started the car today, it's been sitting a while. Ran the A/C. Blows cold. Was in the engine bay and noticed metal lines that sit over radiator. The lower one was cold and had condensation. The upper one was hot to the touch. Not sure if I've ever encountered that before or simply never paid attention. Is this normal? Or do I have an issue?

Also, noticed that the A/C has decided to blow at the upper and lower vents instead of the regular mid-vents.. I presume it's a loose vacuum line behind the control panel?

 

[ScottHeidinger]

Issue 1 is normal
The second issue is like you said probably vacuum related or the 30 year old vacuum activated air door devise is going bad.


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[turbo39151]

Issue 1 is normal? Really? I don't recall even having one of those pipes get hot to the touch. Hmmm. Maybe I don't
pay enough attention. Thanks for the input.

 

[hflwyo]

Low side line will be cold and will sweat. High side line will be hot.

 

[ScottHeidinger]

Might check the vacuum line that runs by the coil pack on the back of the drivers side. There is a check valve in that area and I’ve seen a couple broken ones. in that area they don’t stand out.
The smaller ac line is your high side. Think of it as a heat exchanger. In exchange for a cold evaporator in your ac/heater box the heat is exchanged into your condenser coil in front of the radiator.
HTH



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[turbo39151]

Good info. Thanks. I'll double check. A/C is ice cold. Just was weird to touch the hard line and have it be so hot...

 

[Buckshot G/N]

Good info. Thanks. I'll double check. A/C is ice cold. Just was weird to touch the hard line and have it be so hot...

Did You get A/C to blow out the vents/ this has been ongoing issue on these cars for over 20 years. I was always told it was the
blend door actuator needs to be replaced. I just gave up on trying to repair the problem, and just live with it. One thing for sure I
do have cool feet . Lol...

 

[turbo39151]

There is apparently a small vacuum piece (a small black disc) that goes bad and defaults to defrost and foot well vent. I have the HAVC pieces pulled apart but I have yet to pull the small disc as I'm not sure how (without breaking something)... I'll get to it eventually. I also need to look at the check valves, I understand that they go bad as well...

If anyone has tips on removing the small black disc, please post up! Thanks,

 

[captndave737]

Mine was doing that last week. I pulled out the control head just enough to wiggle it and make sure the vacuum lines were on right. Pulled them off and reinstalled and all is good now.
gbody parts has this.
.https://gbodyparts.com/product_info.php?cPath=46_21_174&products_id=1288&osCsid=112ba072f6f957cc41257a4772c81f62

 

[turbo39151]

I was looking to inspect the vacuum switch- (the black piece pictured above). I am not sure how to pull it out and don't want to break it. Does any one have a link to a DIY on removing this piece... Brittle 20+ year old plastic requires a delicate touch.

I'll also be disconnecting and reconnecting the hoses. I already pulled the other switches and cleaned the copper bits with some "0000" steel wool. That should ensure an nice connection.

 

[turbo39151]

Bump...

Anyone know how to remove the vacuum switch (small black disc)?