AC woes

[Magnetic82]

Hello all:

I am still trying after a number of years to get the ac working in the 86GT. I've replace all three lines, have a resealed original compressor, and cleaned the evaporator and condenser on the car thoroughly. Still nothing. The system refuses to even take a charge. So I replaced two of the lines again as I thought I had too much PAG oil in the line between the compressor and tank. Also the line from the condenser to the firewall. Thought the orifice tube might also be jammed up. Now there is apparently a leak as it will not hold a vacuum. All gaskets are new and lubed with PAG oil slightly. Not sure how to find the leak. At the end of my rope. Another hot summer without ac and that means I don't drive it. Sigh. Any thoughts or ideas are helpful now. Also tired of spending money.

Cheers.

[wraithracing]

Sorry to hear your GT is giving you such headaches. In my experience, I have often used compressed air to blow out the A/C to make sure there are no blockages before beginning repairs. Especially when the system is unknown, hasn't been charged in years, or has been left open at any point in time. I will generally disconnect the lines from the compressor and blow air through the evaporator and the condenser to verify that neither is blocked or clogged. I normally start with a new liquid line since there's usually no way to verify the condition of an old line. I install all new O rings and spring locks on all connections to make hopefully make sure everything is sealed and will hold a vacuum. Then I will pull a vacuum on the system and allow to sit overnight to verify that everything is sealed. If not, then I start checking all my connections, lines, hoses, etc to find the leak. Also keep in mind that old hoses can leak through the rubber itself, so often that can be a source of leaks that are hard to find.
Once I know the system is good to go, I will add any oil needed for proper operation, pull vacuum on the system again and then charge the system as needed for proper operation.

If you have a leak detector, you can put a charge into the system and that should detect where the leak is located, then repair as necessary. Sometimes you can find the leak which pulling a vacuum on the system, by spraying some carb/brake cleaner at the connections while watching the gauges. If you see a jump in the vaccuum level that often will be the source of a leak if the leak is significant. Really small leaks can be much harder to find. The front seal on the compressor is another area that is prone to leaks as the system ages and wears.

Worse case, is take the car to a certified A/C shop and have them repair and recharge the system. They can actually charge it with R12 if they are willing to purchase R12 and/or have someone that has actually filled systems with R12 in the past. A much better option than R134a if you can get someone to refill using R12. Hope this helps.

[Carbsovertech]

I’m wondering if you jumped your solenoid switch? My uncle told me they won’t take a charge from empty and I should jump my solenoid switch. I tried but my compressor still wouldn’t engage, I had a crappy jumper wire And that’s as far as I got. So next thing I will do, eventually is better jumper wire and run 12 volts straight to compressor and see if that kicks it on.

[gt4494]

I've even used a paper clip or a cotter key to by pass the switch. any metal condiut will work.

[emerygt350]

It is nice to have ac working. I have r134 in mine and it is ice cold. I assume yours is converted already?

[Magnetic82]

The car was converted a few years ago. Right now with it not holding a vacuum, I need to find the leak. Once that is solved, I can install a new pressure switch and try to recharge it. I have heard about jumping the switch at first to get the system moving. I'll keep at it, work schedule permitting. Plus weather. Thanks for the advice. Let's hope things improve.
Cheers.

[bob85gt]

what i have done in the past it to connect a can of r134 to the low side. then with a mixture of soap and water in a cup. using a paint brush wet the hose ,connection and fitting looking for bubbles. do not get water in the low/high fittings.

on the low and high pressure fittings i have put a small balloon on them and if they expand, you found a leak. but the system must have some pressure in it.
good luck

[Bentley]

Did you remove the condensor and Evaporator and have them checked?? I believe a good radiator shop can do this. Little bit of pressure and submerge them in their tank.....
On another site the same story, finally found the leak in the Evaporator.....
A fella in the know was saying its easier to find an AC leak with some pressure instead of a vacuum....

[Magnetic82]

Good ideas. Not sure why my system won't take a charge but did manage to replace all the o rings this morning. Pulled a vacuum and it leaked out slowly but still leaked. Took about 6 minutes total to go to zero. I pulled the fittings off and they weren't in too good shape. The low port doesn't have a gasket at all and the high port had two- one was green and near the outside threads and the other was a thin black thing inside the fitting and it was just about toast. So I think new fittings are in order with good gaskets. Then try again.
Any suggestions on brands and the right stuff? What's on there now was parts store brand from a few years back. I think the kit was generic and only one fitting matched up correctly per port. I have plenty of new green gaskets but want a high quality adapter and I might be in business.
Thanks again.

[TheWizard]

Double check the little O-ring inside the pressure switch, sometimes they twist or bind when you screw them in, creating a hard to find leak. Ask me how I know.

[graphicdesigner80]

Any suggestions on brands and the right stuff? What's on there now was parts store brand from a few years back. I think the kit was generic and only one fitting matched up correctly per port. I have plenty of new green gaskets but want a high quality adapter and I might be in business.
Thanks again.

The only fittings I've ever had good luck with are Murray brand you can get at any O'Reilly Auto Parts. Possibly available elsewhere, but that's where I source them. The generic ones always ended up leaking and are made of cheap aluminum. Don't waste your time with those anymore! These are much more robust and won't strip out with the lightest amount of torque. I went through a lot of frustrating leaks and wasted refrigerant before a fellow that ran an a/c shop pointed me to these:



High side
Low side

I run these on all my converted setups and they're all holding up many years later.

Hopefully that'll get you going. Good luck! It's 104* right now in Round Rock, Texas. Long live a/c!

[Magnetic82]

Amen. I haven't heard back from the supplier of the new fittings which didn't work. So I might look into the new ones.
Since there are still two valves on the lines now even without the new fittings, how might I get those out? I think that may be the problem now as with two valves they struggle to open properly. If I just put some kind of adapter on them the gauge manifold doesn't seem to be able to open the valves. Definitely will look for the ones suggested. Its still hot here, too. Maybe 90 today. Yikes. Job openings in Alaska?
M

[Chuck W]

You can remove the valve cores with a valve tool. It's similar to what's used for the cores in car tire valves.

You can't install fittings with valves in them on top of ones that already have a valve in them. You either need an adapter fitting w/o a core, or remove the one from the old R12 fitting.

I just did the AC retrofit and charge on the LTS this past weekend. The high-side wound up using an adapter with no core in it, but on the low side, I removed the core from the fitting on the compressor and installed the retrofit fitting WITH a core.

[Magnetic82]

Had another go at it today. I removed the valve cores on the car- the high side in the line to the condenser and the low side in the compressor manifold. Installed the new Murray fittings and pulled a vacuum. The vacuum held. Surprise. But when I went to charge the system I got the same result. The system will NOT take a charge at all- not a drop. I jumpered the cycling pressure switch a few times to prime the system but nothing. I don't understand this at all. All new lines, a rebuilt and resealed compressor, cleaned evaporator and condenser (twice) and good connections with all new o-rings. Good vacuum. Didn't lose anything for many minutes. So I'm giving up. This car won't have AC which means I only drive it during cooler weather. Since it needs painted bad, I probably won't drive it at all. Shame. I have no idea what to do next. Taking it to a shop will only ruin the compressor, which is a factory compressor I rebuilt and resealed. Auto folks around here are idiots. Looks like I'm quickly becoming one myself. Too late to shoot it?

[Chuck W]

Did you fill the compressor with oil when you rebuilt/installed it?

When I did the AC in my LTS recently, it was completely empty. My compressor had oil in it, so I just jumpered the cycling switch and even though it took a while for it to finally take a charge, it eventually did.

[KevinVarnes]

Why will taking it to a shop ruin the compressor?

[Magnetic82]

Its happened to me before. They either over pressurize the system to get the dye to leak out and 'prove' to me the compressor is bad or they just don't know what they are doing. I can't find anyone around here that is willing to paint it either. Someone actually quoted me $12,000 to paint a car that might be worth 4000 on a good day. Besides, I don't find ac work real difficult. Maybe the compressor is not working right. The clutch is good and when I reassembled the compressor with the proper oil, it rotated just fine. I don't want to force the thing to run and it not take in any refrigerant. Might try again. Not sure.

[Chuck W]

Like I said, I just jumpered the cycling switch (Per a recommendation) and then just started to try and get refrigerant into it. I did wind up sitting the cans in some hot water. Especially to help get the last bits out.
I did also wind up with a bad can too that wasn't allowing refrigerant out.

At some point while things were running, I realized that I'd still had the switch jumpered (Like when I was working on getting the charge to final pressures), so it had been running for a while. I just pulled my jumper and plugged it in and let it keep going. I don't think I'd worry about compressor problems by leaving it jumpered for a bit to get refrigerant into it.


This was honestly my first attempt at doing AC work, so I'm surprised it worked

[Bentley]

Its happened to me before. They either over pressurize the system to get the dye to leak out and 'prove' to me the compressor is bad or they just don't know what they are doing. I can't find anyone around here that is willing to paint it either. Someone actually quoted me $12,000 to paint a car that might be worth 4000 on a good day. Besides, I don't find ac work real difficult. Maybe the compressor is not working right. The clutch is good and when I reassembled the compressor with the proper oil, it rotated just fine. I don't want to force the thing to run and it not take in any refrigerant. Might try again. Not sure.

Is that the state that Pocahontas runs???

[darkd0r]

Have you checked that the compressor has suction when it is running? Since the system is empty, you could disconnect the line from the accumulator/dryer to check. If no suction, maybe disconnect the output line also? Obviously not run it too long because it should blow some of the oil out the high pressure side.

[slow84lx]

JACook doesn't post much anymore but he always had the best advice on A/C systems in our cars and was able to explain it in easy to understand terms. Here is a post where he describes how to properly charge your system from a deep vacuum.

http://vb.foureyedpride.com/showthre...79-Recharge-AC

There are a lot of other good posts on getting your A/C working on this site. Sometimes it is easier to do a browser search using the forum name vs. a search on the forum.

Don't give up, go out there and try it again. Good luck!

Jonathan

[Magnetic82]

I'll definitely try again. Might just need to run the compressor longer with the pressure switch jumpered. I like the suggestion of checking suction by removing the lines at the compressor- that might explain a lot. Still really hot here. And this state is run by, well, rhinos and rats.
Cheers.

[Magnetic82]

WEll, I managed to check the low pressure side of the compressor to check suction and it was present. Upon attempting to start the car to check the high pressure port the starter died and now I have to change the starter. Great. Then I'll try again. I think this car is cursed. Or maybe I am. If the compressor is pumping out pressure but the system still can't be recharged, I'll be totally stumped. May have to reseal the compressor again. What are the chances of getting multiple replacement lines that don't work?

[Chuck W]

Sorry you're having so many issues with this.

JACook's post in that link above gives some good hints at charging an empty system. I'm going to save those notes for the next time I need to do this.

[Chuck W]

So. What hoses/gauges/fittings are you using for this?