Red Nightmare Posted November 24, 2011 Report Share Posted November 24, 2011 In the GTP, I recently replaced the battery and noticed the hoses that were cut would not be as hard to replace as i originally thought... It looks like two hoses were cut but I don't know if there was an adapter or what so I will investigate this at a junkyard to see if any other components are missing and if it's practica to replace... Anyways before the summer, i would like to get the AC system in good physical condition and recharge it. Right now I don't know if the compressor or other components are good. Assuming they are - Once everything is in place, will it work if i just recharge it? There is nothing in the system as the hoses were cut (not by me, car was like that when I got it.) I have heard talk about purging/evacuating the system but would that still be necessary? Is there a way to test the other components without the system being charged? Also, the fan and everything work Quote Link to comment Share on other sites More sharing options...
Red Nightmare Posted November 24, 2011 Author Report Share Posted November 24, 2011 this looks to be the part that is cut Quote Link to comment Share on other sites More sharing options...
Schurkey Posted November 24, 2011 Report Share Posted November 24, 2011 (edited) Right now I don't know if the compressor or other components are good. Assuming they are - How long has the system been open to the atmosphere? AT MINIMUM you'll have to flush the evaporator, the condenser, and replace the desiccant pouch which means a new receiver/dryer, accumulator, or whatever else they're calling it nowdays. Your goal should be to remove every possible drop of contaminated refrigerant oil; and if it was me, I'd REMOVE the evaporator and condenser so they can be leak-tested before reinstallation. Some folks will disagree. The last system I did, ('77 Firebird) the evaporator and the condenser went to a radiator shop for flushing and leak testing. The evaporator tubing had perforated, but the rad shop managed to weld patches onto it, which is good since the parts were discontinued from GM and in the aftermarket. You will have to add the proper amount of refrigerant oil; and you're INSANE if you don't replace every O-ring in the system. If the system uses an expansion tube like the older GM CCOT A/C systems, you're crazy to not replace THAT, too. I kinda think your system does not have the expansion tube, though. Once everything is in place, will it work if i just recharge it? There is nothing in the system as the hoses were cut (not by me, car was like that when I got it.) Wrong. The system is FULL--of AIR. Air that includes ambient humidity, which means water entry into what should be a sealed system--and the water has been corroding stuff ever since. MAYBE it's not so bad inside, but the desiccant pouch will be saturated and useless; and the flushing of the main components will remove most of the contaminated oil. It MAY be that the desiccant is located in one of the aluminum "bottles" pictured with the hose assembly. I have heard talk about purging/evacuating the system but would that still be necessary? The air--and the humidity it contains--absolutely positively has to be removed. That's the purging/evacuating (evacuation) you've heard of. You seal the system, connect a vacuum pump to it, and "vacuum clean" the system with as close to a hard vacuum as your tool can generate. Some folks will say that an hour or less is sufficient...I leave the system under vacuum for as long as I reasonably can; which is to say "overnight" if possible, and never less than four hours. But then, I'm an extremist. Is there a way to test the other components without the system being charged? Also, the fan and everything work There's no good way to know if the compressor is still viable. You can do bench tests on the other system controls. It never ceases to amaze me how some boneheads can ruthlessly destroy an air conditioning system with the goal of "removing weight" or getting rid of "complexity"; and never having a thought for the poor bastard that comes along later who wants the system working again. Edited November 24, 2011 by Schurkey Quote Link to comment Share on other sites More sharing options...
White93z34 Posted November 25, 2011 Report Share Posted November 25, 2011 It never ceases to amaze me how some boneheads can ruthlessly destroy an air conditioning system with the goal of "removing weight" or getting rid of "complexity"; and never having a thought for the poor bastard that comes along later who wants the system working again. Let me tell you ALL about that My advice. replace damaged components. replace drier. replace orifice tube. Replace seals in that area. Inspect the condenser, likely replace that too, those go often from rock hits to road salt. Put a vacuum pump on it for a hour or so. measure this with manifold gauges. if it looses vacuum you have a leak. fix and correct. Quote Link to comment Share on other sites More sharing options...
AliasCT Posted November 25, 2011 Report Share Posted November 25, 2011 I've been looking to repair my A/C for when the summer rolls around too. One thing I've always been curious about... What's the "proper" way to replace the oil in the system? Quote Link to comment Share on other sites More sharing options...
Schurkey Posted November 25, 2011 Report Share Posted November 25, 2011 I've been looking to repair my A/C for when the summer rolls around too. One thing I've always been curious about... What's the "proper" way to replace the oil in the system? Flush the major components, this removes all oil from them. Drain compressor as best you can. The old GM compressor (A-6) had it's own oil sump with a drain plug; the newer compressors don't have a sump far as I know. Find the service manual for oil capacity, dump a couple ounces into the compressor, (be sure to turn the compressor no less than ten full revolutions BY HAND afterwards) and the rest into the accumulator/receiver-dryer, or wherever the service manual specifies. The oil gets carried around by the refrigerant movement, so that some ends up in the evaporator, some in the condenser, some in the hoses...you get the idea. If you're not starting from "empty", you have to guess at how much oil was removed or leaked out, and then it can be added back into the low side during recharging by using a can of "oil charge", refrigerant oil mixed with enough refrigerant to push the oil out of the container. Not near as precise. Too much oil makes for warmer air temps at the dash; too little risks burning up the compressor. Quote Link to comment Share on other sites More sharing options...
alec_b Posted November 26, 2011 Report Share Posted November 26, 2011 (edited) Schurkey is correct- Any time an A/C system has sat open for more then a few minutes, it needs to be flushed with solvent in EVERY component: condenser, evaporator, and all lines. The compressor is a crap shoot, although in your case I'd almost put money on the fact that the compressor is junk. Lots of time when an A/C system has been hacked like yours it's because the compressor took a crap and no one wanted to fix it. That's how it was with my t-bird. To start, I'd recommend this kit: http://www.ebay.com/itm/NEW-AC-COMPRESSOR-AND-DRIER-KIT-20215-/370560803634?fits=Year:1994|Model:Grand Prix&hash=item5647252332&item=370560803634&pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr It gets you off to a good start. New accumulator, new orifice tube, new/reman compressor. $170 shipped is NOT bad, those parts will easily cost you double that in town for the same package. Also, buy a universal o-ring kit from your local parts store. It will have lots of various sizes, just match up to your old ones and install. Replace EVERY o-ring you see. You may also have flat washer-style gaskets on your compressor, those are available at most good parts stores, or GM. General rule of thumb with adding oil is each component will hold 2 oz of oil, for a total capacity of 8 oz. 2 in the compressor, 2 in the accumulator, 2 in the evaporator, and 2 in the condenser. However, with the evap. core and condenser mounted in the car it's impossible to add oil to them. Generally I don't like putting more than 3 oz in the compressor, it's better to have more in the accumulator and less in the compressor at initial start up. After you've got everything replaced, take it to a certified garage that can vacuum the system down for at least 1 hour. This ensures that every bit of moisture and lingering solvent are removed from the system. Then they can add leak-detecting dye and oil (if necessary) and recharge the system. Enjoy your working A/C! Edited November 26, 2011 by alec_b Quote Link to comment Share on other sites More sharing options...
paulo57509 Posted December 5, 2011 Report Share Posted December 5, 2011 There are no shortcuts when working on your AC system. The only way to know how much oil is in there is to start with an "empty" system. Replace oil per your FSM. Some in the compressor, some in the accumulator; your FSM should tell you total capacity and how much in each component. If you're flush (no pun intended) consider a new compressor. Rebuilt components are usually OK.....except when it comes to AC compressors. It'll save you a lot of headache to just install a new one. If you need more info about working on AC systems, go here and spend a few hours reading. Lots of good and correct info. http://www.autoacforum.com/ Quote Link to comment Share on other sites More sharing options...
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