Guys,

Just prior to my move from MO to CA, my a/c died. As in, at the bottom of the driveway, getting ready to pull up the hill (in MO). DOH!

I had just backed the trailer up to the garage, shut the truck off, and climbed out. I heard this "Pffsssssssssssssst" sound...you know, the sound of gas escaping. At first I thought I had picked up a rock in a tire. I checked both tires, and found nothing. Then I noticed the sound was coming from in between the tires. I popped the hood.

Sure enough, the pfsssssst sound was coming from the engine bay. I wasn't able to *feel* the escaping gas anywhere in order to pinpoint the leak, but it *sounded* like it was coming from the front of the engine, near/at/under the manifold area. I know this probably isn't the exact point, but that's what it sounded like.

I didn't see any fluid on the ground, and it didn't take me long to realize the only gas that could escape was the freon. The a/c went from being ice-cold, to blowing "kinda cool" air. This was during the day, with temps in the mid 80's. That night, as I was on the interstate, the air actually blew quite cold. I don't know the temps, but call them in the 60's. After that point (OK, TX, NM, AZ, CA) the air would not blow cool at all. It became a fan-only.

So, now I need to charge/fix my a/c. Any ideas on what could have blown, and killed the a/c? It was probably just an O-ring, compared to a whole line, right? This is the perfect time to convert to R-134a, but of course the system needs to be leak-free first. If I can fix the system (short of re-charging) myself (to save some $$$), I will. If, however, it *needs* to see a shop, I'll do that too.

I'm looking at 2 stages right now: 1) find/fix whatever caused the coolant leak, and 2) convert to R-134a.


Any help/advice that can be offered would be much appreciated. FWIW, the truck in question is a '94 Ranger x-cab 4.0 auto 2wd.

Thanks,

Brandon

 

The first thing that needs to be done is find the leak. If you can't see any obvious damage, look for any oily residue on the A/C lines and fittings.Thats where the leak will be.Check the condensor for any punctures. Anything short of a major repair, I would just charge it back with R-12.

 

I doubt you have a freon leak detector so your only hope is to feel around all the hoses, lines with joints, all around the compressor feeling for oil. If you can't find any, take it to a shop and they will find it. You could also buy a few cans for 134 and put it in and find the leak by feel/hearing maybe. Don't run the vehicle too long with the mixture in there though. I had this happen to me one time and the leak was at the joint you pull apart where the small line coming from the condensor connects to the tube coming out of the evaporator. I forgot to shove the spring loaded connection together good enough and the pressure caused the joint to separate. I doubt this is where your problem is but worth checking that too.

 

When I bought my Mustang the A/C didn't work. When I was giving it a service I was having trouble getting the airbox lid on and noticed the A/C line below it was apart. I bought some new o-rings, installed them and pushed it back together. I took it to a shop and had it evacuated and leak tested. They then charged it and it worked great.

Maybe one of your connections on your truck is in an area that may have been pushed on at some time. Check those connections first. The one that is the worste is right on the the air box. This is a longshot but check to see that your motor mounts are OK. Just open the hood, start your truck and rev the engine a little, put it in gear and move it about 5 feet both forward and reverse to see if the engine is moving around to much. If your engine is moving it could stress the lines somewhere.

They do make some weird sounds once and a while, what you heard may have been normal and it could be one of the pressure switches has gone bad or you lost power somewhere and it isn't getting power to the compressor clutch. The first thing the shops usually do is jumper across the where the switches go and to try and get the compressor to turn on, if they can't do that then they will check power which goes to the pressure switches down the line to the compressor. If they can get the compressor to turn on then they will put the gauges on and check the charge. The A/C will usually kick on and off every couple seconds if one of the pressure switches goes bad, they can do this for a long time or for a short while and quit. I can't believe your 94 isn't 134 already.

 

Its possible the high pressure pop-off valve vented off some freon when head pressures got way up there. Possibly you have a bad fan clutch allowing head pressures to exceed 400 PSI on the high side.