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Gene	08-06-2008 09:53 AM

Another A/C troubleshooting question

Got a 71 Chevy with factory air, charged it last season and it just barely got cool afterwards. Now i'm trying to get it up and going this summer and here's the problem. The compressor kicks on and stays on, the line at the bottom of the evaporator is pretty cold but the air coming out of the vents is not. I know the door is in the right position because I can manually move the door and when I do that the vents blow hot! A freind told me that the expansion valve is dirty or stuck but I need some verification.

Thanks!

Andy4639

08-06-2008 10:03 AM

Re: Another A/C troubleshooting question

When you did the recharge last summer did you pull a vacuum on the whole system? Before you charged it. If not you need to. A clogged POA valve or it's not working at all. Sounds like you need a good over haul on the whole system. The condensor could be clogged, evaperator there could be numerous things wrong with the system.

Gene	08-06-2008 10:06 AM

Re: Another A/C troubleshooting question

Quote:

Originally Posted by Andy4639 (Post 2838034)

Yeah, had a vaccum pulled when it was charged. It held and didnt lose vaccum.

Willys47

08-06-2008 10:37 AM

Re: Another A/C troubleshooting question

make sure you don't have the hot water running through the heater core some times the valves dont close and it lets the hot water through and you can't cool down all that motor with the a/c system.

Gene	08-06-2008 10:53 AM

Re: Another A/C troubleshooting question

Quote:

Originally Posted by Willys47 (Post 2838089)

make sure you don't have the hot water running through the heater core some times the valves dont close and it lets the hot water through and you can't cool down all that motor with the a/c system.

You know, that makes sense. I have a valve that is supposed to shut off the water to the heater core but it is not closing and letting hot water through to the core. If I bypass the heater core it should tell me if thats my problem. I'll give that a shot.

mrein3

08-06-2008 12:59 PM

Re: Another A/C troubleshooting question

Quote:

Originally Posted by Gene (Post 2838102)

Or just manually shut the valve and wire it shut. Then you don't have to open your cooling system and have to burp it, etc.

Gene	08-06-2008 01:04 PM

Re: Another A/C troubleshooting question

Quote:

Originally Posted by mrein3 (Post 2838280)

Or just manually shut the valve and wire it shut. Then you don't have to open your cooling system and have to burp it, etc.

Well, I bypassed the heater core and it still isnt blowing cold?? Should both top and bottom tubes to the evaperator be cold? Because only the bottom one is cold?

Willys47

08-06-2008 07:22 PM

Re: Another A/C troubleshooting question

it should be cold after the xpantion valve

JimKshortstep4x4

08-06-2008 08:39 PM

Re: Another A/C troubleshooting question

Does the sight glass have bubbles in it or does the refridgerant flow look good?

Jim

Botietruck

08-06-2008 08:55 PM

Re: Another A/C troubleshooting question

Gene, for what it's worth, if you have the original system and want to keep it that way, you will have a very hard time finding NOS parts.
I came across a company in Tampa FL that will recondition pretty much any a/c part you have. I sent my expansion valve to them and got it back in 3 weeks. It was completely reconditioned and refinished with zinc plating. It cost me $72.40 and that included shipping. That might be an option for you. Their name is Classic Auto Air Mnfg. Co. (813) 251-2356

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