Question about my AC

rnln · 04-12-2007, 09:22 AM

I was fed up with my AC before talking to HughR. After talking to him, I decided to ask a question again. Honestly, I don't know much about AC. First thing I khow is the AC in my 87 cab is worse then sht. I brought it to a shop to pump some freon. Get out of the shop, it's cool a bit but not that cold. Couple weeks later, it's back to before. I brought it back and they pump some more and it's last for another couple weeks. This is before I decided to forget about it.

I know it's impossible, or maybe too expensive, to have a "normal AC" as on normal car but at least I want to keep what I can get on it. So first thing I need to know where does it leak. Can someone help?

Anyone in OC SCal who successed their AC work? Do you have some free times on the weekends, maybe we can have some coffee together?

1982911SCTarga · 04-12-2007, 09:37 AM

Do a search on A/C repair or A/C leak. There are both higher- and lower-tech ways of finding the leaks in your system. How DIY-capable are you? By the way, I think my SC's A/C is pretty darn "normal" (decent) in terms of performance, but it took some time and effort (but not a lot of money) getting there.

Brian

Tim Hancock · 04-12-2007, 10:06 AM

Rnln, the common way to check for leaks, would be to have an AC shop sniff for refrigerant leaks with an electronic sniffer to pinpoint where the leak(s) is/are occuring or to inject dye in the system then use a blacklight to look for leaking dye.

If you are a into the DIY thing, you could do like I did two years ago when I resurrected my AC system in my SC. My system had no refrigerant in it and had not worked for years. Just out of curiousity, I rigged up a regulated air line from my shop air and pressurized the system with air. I then used soapy water in a spray bottle to spray very AC component/fitting/hose to look for bubbles. I ended up finding a gross leak in my low pressure line near the jack point under the right side floor pan.

Someone had obviously jack my car incorrectly at some point and crushed my oil lines partially and pierced my AC hose. In short, I spliced in a patch, installed a new drier,pulled a vacuum with a vacuum pump, then charged the system with a 134 refrigerant along with a shot of 134 oil. My 1979 stock AC system worked great for 2 summers on this initial charge and this spring appears to need another 1/2 can of 134, as a couple weeks ago when it was warm and I got the car out, it blew cool , not cold. Worked great for me, but YMMV.

1982911SCTarga · 04-12-2007, 10:28 AM

Tim's original thread (and leak-finding technique) was what I followed in sorting my car's A/C and converting it over to R-134. It works well for our cars because the plumbing is all fairly accessible and visible (ever replace an evaporator on a '00 Jeep Cherokee?).

Naturally, if you pressurize the system with shop air for leak finding, leave your old receiver/drier in place (you'll eventually replace it). You'll also need to vacuum the system.

Ah spring, when 911 owners' thoughts turn to A/C ...

Brian

rnln · 04-12-2007, 10:40 AM

thansk guys,

Tim Hancock,
So basically, after testing and patching the damage hose, you replaced R12 with 134 refrigerant and ad 134 oil to existing system? Nothing else involved to this conversion?
Thanks.

Tim Hancock · 04-12-2007, 10:48 AM

Quote:

Originally posted by rnln
thansk guys,

Tim Hancock,
So basically, after testing and patching the damage hose, you replaced R12 with 134 refrigerant and ad 134 oil to existing system? Nothing else involved to this conversion?
Thanks.

That is pretty much the gist of it. I did however, have a vacuum pump (to remove all the moisture from the long dead system) and an old set of r12 gauges that I used to monitor filling pressure.

The vacuum part of the job is essential and you really should have gauges when filling to monitor proper high side/low side pressures.

Here is a link to my original post DIY 134 conversion in SC complete!

feel free to contact me thru PM or e-mail if you end up needing more info than this post ends up generating.

dralph12 · 04-12-2007, 10:51 AM

Last Year I got my 86 coupe and had the AC recharged. AC worked for about three weeks. Then blow hot air! So I stopped using it. Recently my mechanic pointed out where my AC compressor had leaked out on to the deck lid above the the compressor. He said that leak could be the problem! "compressor needs to be rebuilt or replaced" So you could look there.
The reason why I didn't try to fix this last year was I need to install a fan on the oil cooler. that's done and now I ready for a new compressor, recharge, and a HOT Summer here in the OC. Lord knows!! We didn't get any rain!!

Tim Hancock · 04-12-2007, 10:53 AM

Just thought of something else, my old SC has flared, metal to metal connections throughout, whereas your newer '87, probably has o-ring fittings. If you disconnect any fittings, you might be smart to install new o-rings that are 134 compatable. More than likely the non disturbed r12 oil soaked connections will not leak an appreciable amount of 134, so I would not screw with them unless they actually leak.

Jastx · Jastx's Garage

If your system has been exposed open to the air, you should at least replace your drier.

I did the complete upgrade on my former '89 using a retroair.com kit. It worked out great, so depending on your need for cool air you may consider upgrading your AC technology.

Prior to my upgrade, I had the same apparent leaking problem you do, where it worked well for a few weeks then didn't. I discovered during my upgrade that a Lojack device had been installed in my car (probably in '89 when it was new) under the passenger floorboard. The idiot installers screwed through one of my AC hoses when they bolted the Lojack to the floor!

Tim Hancock · 04-12-2007, 10:59 AM

Quote:

Originally posted by dralph12
Last Year I got my 86 coupe and had the AC recharged. AC worked for about three weeks. Then blow hot air! So I stopped using it. Recently my mechanic pointed out where my AC compressor had leaked out on to the deck lid above the the compressor. He said that leak could be the problem! "compressor needs to be rebuilt or replaced" So you could look there.
The reason why I didn't try to fix this last year was I need to install a fan on the oil cooler. that's done and now I ready for a new compressor, recharge, and a HOT Summer here in the OC. Lord knows!! We didn't get any rain!!

FWIW, last summer I fixed my daughter's '87 924S AC using the same process. I found the leak was a case leak in the Nippondenso compressor. I found a seal/rebuild kit for it on-line (some auto AC only supply house out of Arizona IIRC) and tore it apart and installed new case seals and a new carbon type shaft seal. I then installed a new drier, vacuumed it down, filled with 134 along with a can of the oil charge and it has worked great ever since (basically only one summer, but so far, so good).