Off topic, sorry, but need help with automotive A/C system repair
 

Sorry for the off topic post:o, but there’s so much knowledge and talent on here I thought I’d give this a shot. I’m starting life over after a divorce down here in Houston (Kingwood, to be exact), and can’t spend a whole lot on a new car. I ended up buying a high mileage 1996 Grand Cherokee Limited with a V8 engine. Problem is, the A/C doesn’t work. It clearly needs a compressor, as it’s making a racket when turned on. I have been told that it will need a receiver/dryer any time the compressor is replaced as well. I was hoping to do the compressor and receiver dryer myself, and then get the thing flushed out and re-charged. I readily admit that I know little about A/C, except that it’s horrendously expensive to get it repaired, hence the self repair attempt. I did get some ideas about getting it repaired down here, and all agree that by the time I’m done it will be well north of $1K. I just can’t do that now. The parts are about $350 for the compressor and receiver dryer. Anyone with experience or knowledge in this area, I would really appreciate your input. What is the least expensive way for me to get this repair done? I can easily do the bolt on for the compressor. How difficult is the receiver dryer to do? If you’d rather PM me that’s fine too. Thanks.

Last year I bought a 20 year old car that was fundamentally sound but still needed some work including the A/C. I wanted to do all the work myself so I ended up buying a new compressor, clutch, dryer, vacuum pump, R134 conversion kit, A/C gauge and hose set, and several cans of R134a refrigerant. My system had leaked every bit of old coolant out before I bought it, so I didn't have to worry with recovering the old Freon. If I had wanted to deal with that issue, I would have taken the car to a qualified repair facility and had them pump out the old Freon.

In the end, all I had to do was disconnect, remove, replace and reconnect the parts. Next I drew a vacuum on the system to remove all the air in the lines. Next I connected the A/C gauge and hose set with a fresh can of R134a and charged the system. It worked like a charm. As I recall, the replacement parts came from an Internet seller for less than $200 and the tools and refrigerant came from Harbor Freight and AutoZone for a total of less than $100. As car repairs go, it wasn't a bad job on my car.

Bring it by and let me check it out.

Doug, Mitch will take good care of you and he a great Superformance/Cobra shop. But if you decide to do it yourself, just get a good reman'd compressor and a dryer and follow a Chiltons manual or similar and be careful with replacing o-rings as prescribed. Also confirm if your compressor comes pre-oiled or if you have to add oil and tell the recharging shop accordingly. Its all straight-forward plumbing once the old system is evacuated. I had a local shop draw everything on my son's 4Runner, we mounted a new compressor and dryer in a couple of hours and paid them $90 to recharge.

Jim

If I was really pushed for the cash, which mostly I am, I'd go with a USED compressor from my local junk yard. I would NOT change the receiver/drier. If I didn't have a vacuum pump I'd "purge" the system by blowing freon in one pipe and out the other end. Then while there is still a bit of pressure in the system (can of gas slightly open feeding the inlet side) I'd tighten/connect all required fittings to seal it all up.

Then I'd start dumping the gas in on the low side. I would probably turn the can upside down initially and introduce liquid freon at first. But thats somewhat risky and depends on what type or kind of gauges (if any) and additional devices you have to keep the liquid from becoming a problem and damaging the compressor. Plus, you gotta have kind of clue about what your doing. Oh, I think I'd add some compressor oil to the compressor or introduce it to the system as well in some way. Hard to tell how much, if any, oil the system has lost or the junkyard compressor had in it in the first place. You could try draining the compressor and then measuring the correct amount of oil back into the compressor, then add a little more for the system (just to be sure).

Now the BIG problem with the Cherokee is the evaporator drain. If that get's plugged up the water spills out of the evap and onto the passenger side floor, soaking the rug. Punch a couple of holes in the floor for the water to run out of the passenger foot wheel area,,,, just sayin'... :) Normally you would blow out with air or run a wire up through the drain to clear the blockage, that aint gonna happen on the Jeep. Your pretty much screwed. Technically you have to remove the evap to clear the drain (remove the dash, etc. a monster nasty PITA project). Here's my thinking on that, there HAS to be a way to drill a hole in the dang frame to access the stupid drain pipe and blow it out and ream it out with a wire. Problem is, WHERE do you drill said hole? Would said hole even work? I sold the Cherokee before I could find out but AFTER I removed the dash and the evap, cleared the drain and then it plugged up again a month later.

I have nothing good to say about the Cherokee from that experience, all though, I thought the V8 was pretty cool, loved the power and the 4 wheel was dam good in the woods. The AC sucked really really bad... :)

You really do want to replace the dryer if the compressor is blown. That is the first place the small chunks will get caught and the dryer is a very important part of the system working correctly. The dryer is the least expensive of all the major components.

Not much to loose with a junk yard compressor on the cheap, in which case, I wouldn't replace the drier. Now if it's a fairly inexpensive drier, it's good insurance even with or because of going with a used compressor.

New or rebuilt compressor? You'd be a fool not to replace, purge and vacuum the system according to industry standards in that case.

...all that money only to find the evap drain is plugged, then your screwed anyway which way you go. :)

I had a compressor go bad once. It powdered up metal and it was everywhere in the system. I tried flushing it real good with a fluid and compressed air. Thought I had it all. Put the new parts on and the orifice/screen plugged up and shot the pressure through the roof. I ended up having the dealer flush it out. In the end, I could have had it fixed at the dealer for the same money I had in it, and never touched a tool. In fact I could have replaced every part, hoses, condenser, evaporator, ect. first time around for the same money.

If you cannot spend the money to have it done, take Ernie's advise and go with used parts. At least then if you screw up the replacement parts, you won't have much money in them.

Thanks, everyone. The main problem here is a concurrent lack of funds, knowledge and talent.:LOL: I can certainly unbolt old parts and bolt new parts on, what to do from there is beyond me. I have no idea how an A/C system works. I have been in Houston long enough to know that when it's approaching 100 degrees and the A/C doesn't work.....well, that's no good!:eek:

Mitch, if you're willing to take a cursory look at the situation I'd certainly be appreciative. I'd love to take a look at the Cobra's anyway! I'll give you a call to set up a time that's convenient for you. I'll send you a PM.

Thanks again to everyone for all the advice.
Doug

Replace the oriface tube or expansion valve
 

767 Jockey Doug if you stayed here, I could have helped you. Any way. This is very important, There is either and expansion valve or oriface tube, If the compressor is broken or coming apart internally it need to be replaced.
Before you get crazy. Go and have someone do an ac service on the system. The compressor may just be low of pag oil. Is the clutch on the front of the compressor looks wierd in color. The compressor may be fine and the clutch is breaking. You have the rest of the info you need. Replace the parts and go and have the system vacuum and recharged. Have them sweep for leaks also. You might want to look for a place selling a B&G a/c recharge kit. Comes with oil and a freon booster. Rick L

I agree, replace the orifice tube and accumulator. I just did this on a "ebay special" I picked up for daily commuting. It was easy. Also, check the O-rings when you disconnect everything and replace those in question. Have Pep Boys or some other shop pull a vacuum on the system after you replace the compressor for 30 minutes to get everything dry (moisture), then recharge as the folks above have stated.

good luck

if the compressor is making noise it is most likely the clutch that is going bad, see if there is any play in the clutch or if you have a burnt electrical smell from the clutch. jeep did have problems with the drains clogging and leaking on to the carpet, we use to drill a hole in the heater box on the passenger side and runna coat hanger through it to unclog the plug most likely form leaves and pine needles going in to the cowl screen on the passanger side then blow compressed air through it, be ready to catch the water inside once you drill the hole i have seen some fill up a 20 ounce soda bottle then just fill the hole with some silicone. the pine needles usually collect on the evap core and rot a hole in it and the smell that comes out of the vents is pretty bad. jeep use to supply a finer mesh screen so the pine needles would not get in to the box in the first place.

Thanks, Rick. I wish I was back in NY with this car, as there are many old friends from my 50+ years there who could have helped me. I'm all alone here, so I'm on my own in that respect. I need to figure out where the orifice tube or expansion valve is and how to replace it. Hopefully Mitch at Vintage can point me in the right direction on that as well. The clutch on the compressor looks OK visually, although I really don't know exactly what I'm looking for. To me it looks ok. I can't even describe the noise this thing makes when you turn it on, it's really loud and nasty. Hope all is well with you!
Doug

Thanks, I'm hoping that once I figure out what piece serves what function and where they all are then it will be relatively easy to do the job. Right now I think my biggest problems are that I don't understand the system, and getting someone to do the vacuum and charge even though they didn't do the parts replacement. That may be an issue.. We'll see. Thanks for the encouragement, I can use it!:LOL:

All good info, thanks. One thing I took notice of, the seller told me that she had most of the A/C system replaced last year, including the "inside coil", I have no idea what she was referring to, perhaps the condensor or evaporator? Would that help with the problem of clogging that you describe?

Inside coil, no doubt she was referring to the evaporator that is under the dash. Thats a really tough part to replace on the Jeep. I believe that model has a classic thermostatic expansion valve, by the way. Replacing the evap wouldn't cause or add to a problem of the system being "clogged" up, it's just a small radiator like thing that "makes cold" (actually, absorbs heat) and a fan to blow air over it.

As the evap was likely replaced by a professional shop one would have to assume it was done according to industry standards? A good vacuum, possible replacement of the receiver drier, oil check and charge, all the normal stuff. Now it sounds like, following all that, the old compressor gave up the ghost, that happens. The good news is, you likely have a nice tight system with good fittings, hoses, evap, thermostatic expansion valve, etc. due to that work when the "inside coil" was replaced about a year ago. More good news is that because it's a "new" evap the drain tube for it is likely open, clean and flowing nicely. Whew, thats a relief!

Ya know, it's a good chance you can simply buy a rebuilt compressor for less than a $100. A used one for maybe $25. You CAN simply bolt it on, fill it with freon from a kit from your local Walmart or NAPA store and go from there. If thats a new receiver drier it may well have captured any debris in the system, thats what it's there for, and you could be OK. Just sayin', it's a poor man's approach and sometimes you get lucky, or your out $25 bucks for a used compressor, plus cost of the freon and kit, and ya still have to get it fixed. :)

One things for sure, duct tape is good stuff, but it won't help with THIS project! :)