73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: 83HighSierra on September 17, 2007, 10:20:19 PM
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Currently my air conditioning isnt blowing cold air. i put freon in it and after 5 mins it was back to blowiing hot air. im pretty sure i have a leak but my a/c compressor kicks on and off constantly when the ac is blowing at its max. Does that mean that the compressor is bad? and what is the best way to find and fix a leak?
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You can put dye in them to find the leak. I would replace all the o-rings in the system and then pull a vacuum on it and see if it leaks down..
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So you dont think the problem is my compressor? where can i get all the o-rings for it and how do i vacuum it?
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just about any autoparts store should have the o-rings. I got the ones for my Suburban from Autozone. You need a vacuum pump to pull a vacuum on it. If you don't have one it won't cool like it should. You could also pressure test the system by adding about 40lbs of compressed air to the system and see if it bleeds off.
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I would highly recommend the vacuum approach instead. The drier in the system can only absorb a given amount of moisture and pumping up the system with compressed air, while letting you find the leaks, will also cause the desiccant in the drier to "fill up" prematurely with the very moist compressor air. You will need the driest charge you can get to get the most out of your a/c.
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Either leak test it with a mechanics stethoscope or with Uv dye as suggested. Once you fix your leak if the system has been leaking for a long time replace the accumulator and the only way to vacuum it is with a vacuum pump. You can get a cheap air operated pump and run it through your manifold gauge set. that's what I used to use b4 I got my vacuum pump. Harbor freight sells them or check ebay. I would also replace the orifice tube and retrofit it at the same time to R134a. Make sure you use a good comatible oil charge. For your system at least 6 oz of Ester will work.
(http://www.harborfreight.com/cpi/photos/92400-92499/92475.gif)
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92475
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92649
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well i dont have a vacuum pump, or manifold guages and im completely lost. Do i find the leak with uv dye replace the orings then what does the vacuum pump do? Would it be worth buying al this stuff or should i just take it to a shop? thanks in advance
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If you don't have it already, it would probably be to much of an investment to get a vac pump.
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well i think i know somebody that has the manifold gauges but no a pump. the only thing that i have is a recharge pump with a guage like this one..
(http://i46.photobucket.com/albums/f105/C-dog01/2178NA1AZRL__AA160_.jpg)
I really dont want to get it fixed at a shop and be overcharged.
what do you suggest that i do?
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Did you see my post above? vacuum pump and manifold gauge set is $50 The rest is fairly easy
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http://cgi.ebay.com/225-Pc-Rubber-Seals-O-Ring-Assortment-Tool-Kit_W0QQitemZ330166577798QQihZ014QQcategoryZ42345QQssPageNameZWDVWQQrdZ1QQcmdZViewItem (http://cgi.ebay.com/225-Pc-Rubber-Seals-O-Ring-Assortment-Tool-Kit_W0QQitemZ330166577798QQihZ014QQcategoryZ42345QQssPageNameZWDVWQQrdZ1QQcmdZViewItem)
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This is what I got, had 25 pieces and I have rear and and had plenty left.
http://www.autozone.com/R,APP1310746/vehicleId,1193410/initialAction,partProductDetail/store,113/partType,01166/shopping/partProductDetail.htm
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Im sorry i didnt realize the ones on ebay for $50. ill probably end up getting that. So once i get it i hit it with dye replace orings, then vacuum the system, then what else??
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don't forget the orifice tube. Replace that. Once you hold vacuum around 29.9 hg's--your manifold guage will have instructions, The guages will aalready be on the high (red) and low (blue) ports. Use a tap for the refridgerant can--the yellow line will hook to the tap/can. Slowly open the blue low side valve...the can will empty due to the vacuum pulling it in. AFter about the second can, you'll have to run the engine w/ a/c on high with windows open. That helps to suck the third can in then check the guages. depends on temp and such but i like to get around 210-220 high side pressure and around 45 or 50 low side if i remember correctly. you can find good instructions from an internet set do a google search. I am going off memory here.
If you are replacing the compressor, you will need to prime that w/ compressor oil, that is usually where i put the dye--oil i use has dye in it. (green)
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83high,,, I notice you are from Houston, have you ever been to the valley? Brownsville, Harlingen, McCallen area? if you haven't i recommend you come by, I will take you to matamoros.There are these A/C shops where they replaced my compressor and vacum tested replace O-rings , new orfice tube filter, cleaned my system(compressed air to remove contaminants from lines and panels) recharged refrigerant oil and best of all R-12 reefrigerant !!!!( so you know it' COLD!) all for under 180.00 dollars.. <you can't beat this anywhere>
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.....all for under 180.00 dollars.. <you can't beat this anywhere>
That is pretty cheap for a shop!
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no i havent been any where around there.
So what about my compressor, it just clicks on and off or is that because there is no freon in it. by the way thank you guys for all the help
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it clicks on and off because the pressure switch on the accumulator detects low pressure and kills the circuit for the compressor (green wire). You can jump that switch for a minute or two (not long though, it is bad for the compressor in low pressure situations) and see if the compressor kicks on. REmove the plug on the switch. Look in the plug, you see two wire contacts. Take a wire and and connect the two wire contacts w/ a/c on and engine running. Does compressor kick on?
Years ago, i had a bad pressure switch ($14.00). I knew the pressure was high, but compressor wasn't working. I unplugged the switch and jumped the two wires---compressor came on.