'92 Chevy Truck AC

[pete44]

Hello...Have a '92 Chevy truck with AC problem...It will work for awhile then it stops...(get a flashing "AC" indicator on temp control unit)...my co-worker says that a truck that old (240,000 miles) could have a clogged "screen" or filter that is located near the firewall on drivers side...he said it is a minor part that would not cost that much to change out..anyone ever hear of this air-conditioning part?.......Thanks,Pete44

[2000CAYukon]

It is called an orifice tube and they are not that expensive; however, if it is clogged, you have bigger problems.

Is there any signs of a leak? Does the compressor even turn on? What is the low side pressure? High side pressure?

There is a picture of an orifice tube on this webpage http://www.id-usa.com/how_to_ac.asp

//2000CAYukon

[pete44]

Thanks for the reply...Appreciate the website reference....Here is what's happening in more detail...I had the pressure's checked at Skill Lube (which is now Express) unfortunately...he said they looked OK and charged it..he then checked it after charge and he said it is holding OK...no leaks...this was a couple of summers ago...AC worked fine for awhile...then the "AC" indicator would flash on and off on my heater/ac control..and of course,NO AC...I then would go out and disconnect/reconnect battery for a few minutes then AC would work fine again...(for awhile)..then same thing "AC" indicator would flash...I was told by someone else this is a low-pressure problem and it is kicking the low-pressure sensor on in turn shutting down compressor..doing the battery reset does not work anymore...But what my buddy said made sense in away..(he works on cars too)..the low side is being clogged from debre from the compressor in a screen or accumulator?..thus causing "AC" alarm (low pressure side) to go off and in turn compressor shutdown..I also wondered if getting codes out of computer would help ...but my luck it would say "low pressure AC sensor problem"..Anymore help/suggestions appreciated...Thanks again,Pete

[pete44]

If it is the orifice tube ...how hard is it to get out on my '92 chevy truck?..I found this site and they mention a tool to extract it....The tube is $15 according to site...And if I have pressure in system what is the easiest way to discharge it before changing the tube?......here is site:

http://www.acsource.com/index.asp?Pa...S&Category=844

[Elbert]

some of those trucks have a problem with the A/C control head. The fix is to replace the control head. I think the other problems related to this blinking light are low freon or a bad sensor on the A/C system... I dont' recall if is a high or low side...

[2000CAYukon]

Originally Posted by pete44

If it is the orifice tube ...how hard is it to get out on my '92 chevy truck?..I found this site and they mention a tool to extract it....The tube is $15 according to site...And if I have pressure in system what is the easiest way to discharge it before changing the tube?......here is site:

http://www.acsource.com/index.asp?Pa...S&Category=844

On a 96 Impala, I was able to get the orifice tube out with needle nose pliers so I don't think you really need the tool; however, I have not done one on my truck. On www.rockauto.com, the orifice tube is a couple of bucks.

You really should take the truck to an A/C shop to be drained before replacing it.

//2000CAYukon

[jocat54]

I have used a sheet metal screw to screw into the middle of the orifice tube and then you can pull the tube and the screw out with pliers. Most of the time you can pull the tube out without any trouble.

[pete44]

Thanks for all the responce....I have already replaced the control head and I tried the re-wiring/jumper trick mentioned in this forum to "fake-out" the control head electrically...Of course,I still get the flashing "AC"....I think I will take it to a auto "AC" shop (not a dealer) and let them vacuum any remaining freon out...then flush out system...then pressure check/re-charge..(during this procedure they will probably detect any defects/leaks).....anyone know of pricing/procedure on this?..I will call a couple of shops on this today and let you know...Thanks,Pete

[pete44]

OK..I called a couple of auto AC repair places....(these are not dealers or Express Lubes)...One quoted a $30 charge to look at it..the other charges $80 for looking at it...they will tell you what is defective and let you fix it or will take off half of the $80 amount if you elect to have them fix it....I am figuring that the $30 one will tell you what is wrong as well...I am going to try them first....wish me luck.....Regards,Pete