Proper Parts Store Ac Fix Procedure

[IS400]

Reposted after members suggested it should go in tutorials section.

Not written as a tutorial but just what I went through and what I learned getting the ac to work.

Original Post starts below :)

Very long post. Grab a sandwich and a beer before starting.

Situation: Bought car in winter and did not check ac. My bad.

Fast forward to a hot spring day and no air when activated. Damn! Lexus told me that they could convert it over but it would be a couple thousand because all the R-12 cars leak some and with -134a a leak is not tolerable.

It got really hot and I looked online and bought a retro kit and installed/filled the system. Did not vacuum it out, did not flush. I know. I know.

Had AC for halfway through the fill and then it went warm again. Online said system is leaking bad and I will have to get it overhauled. Two weeks later I get my Miata and say Bye Bye to summer lexus driving.

Anyway after investigating all the options and even buying a flush and seal kit from lexus recently (another post) and getting a $1,000 quote to install, I wandered into target and wal mart to look to see if anything had changed in the retrofit market.

1. Bought some 134a from target that neutalizes the acid that builds up in r12 systems. Thought what the hell. (4 bucks a can.)

2. Bought some 134a called arctic air that has a synthetic oil that is compatible with r-12 and 134a. (8 bucks, big tall can with a clear fill hose.)

3. Bought an ac fill hose with a gauge and pistol grip at walmart. (12 bucks and fits all standard 134a cans.)

Sat around with the stuff for two weeks wondering how wasteful it would be to just dump in the system like before. Decided to do some research and got on here and some other sites to get an auto air conditioning education.

I learned that the system HAS to be vacuumed to remove moisture so that the physics can work and that even the smallest repair to the system means changing out the filter dryer and accumulator (orifice tube) inside the dash near the evaporator. The filter dryer gets contaminated with moisture from an open system (big leak and/or repair) and the accumulator gets clogged with debris from a leak or a repair job.

After noticing a sale on vacuum pumps at Harbor Freight ($9) I bought one. It is the size of my purse and very light. Has all the fittings to work with any home air compressor. (Illegal to vent system I know. Yada Yada.)

My roof is getting replaced so one night I snagged the pancake compressor they left in my basement and ran it out to the car. Damn thing needed an air tool fitting (not included) to get the hose to mate with the vacuum pump. Found their nail gun and unscrewed the fitting off the base to make the connection I needed. Bad girl, I know! (replaced it after I was done)

Clipped the old hose system I had from when I first filled the car in error (no gauge, just the quick release to the car and the scew on fitting that mates with the pump. As I clipped it to the car it started to discharge some vapor! I assumed it was the old charge I had made and walked away from the car until it stopped hissing.

I went back online and found that my blinking ac light was that the compressor was not connected or was seized. I disconnected the ac compressor (near the pulley toward the fender) and cleaned the electrical connectors (major *BLEEP* of a job! Tight space) applied dielectric grease and snapped it back together. Started car and still got a flashing light. The online advice was that with no charge it will not engage the pulley due to wanting to protect the compressor.

Feeling like this was going no where I almost gave up and put everything away. Instead I flipped the switch and connected the vacuum pump to the air compressor and went inside to wait. The manual to the pump said wait ten minutes to build vacuum and then 20 minutes more to remove watervapor/debris.

Called my boyfriend and checked my e-mail. Looked at the car a couple of times and felt airflow under the pump. No fluid or moisture though. Little compressor only got up to 50lbs and it is rated at 4 scfm or something I think.

Turned off compressor and listened while the vacuum pump slowed. Decided to disconnect at firewall before it stopped completely to preserve the vacuum I'd built and then attached the big artic air bottle since it had the synthetic oil charge. Crossed my fingers and started car and pressed ac button. Attached can (kind of like fix a flat) and had to hold it steady and upright to keep it from leaking as the fluid filled. I stopped halfway through and checked the ac light. It was solid green!

Kept filling until can was empty and then checked vents for cool air. A little cool but more like a fan running over wet skin.

Turned car off and got out pistol grip gauge and installed a can of the acid kill 134a from target. Attached and started car. Pressed trigger and checked pressure by releasing. Barely read on the gauge. Bad feeling already! Damn it!

Tried it again and was tempted to turn it upside down but the online advice was to keep it upright to avoid 'slugging' the compressor with a shot of liquid refrigerant. The whole time I kept eyeballing the compressor to make sure it was still turning and that it was not making death rattle noises or anything similar.

Pretty soon the gauge started to rise as I kept charging and checking and made it into the lower band of the charged area on the gauge. I also noticed that the pressure fluctuated quite a bit as the compressor worked and the the other parts of the system did their thing. The trick is to wait for the system to settle and get a reading from that point.

The second can was empty when the needle was in the middle of the charged area. I remembered that the online guys said that 134a is not as cold as r12 in r12 cars and to make sure to have a full 134a charge to compensate. Attached the last can from target and put half of it in to get the gauge to the top of the full charge section and not into the yellow over charge area.

Got in the car and it was ice cold! I sat in there and wondered, great, but how long will it last? Tossed the gauge with the half filled can in the trunk and packed it in for the day.

Next day to work I did not run ac. I measured it at work and no loss on the gauge! Drove it home with the ac on and left it overnight without checking it. Drove it to work the next day and checked the gauge, no change!

It has been two weeks now and it still cools the car in 95 degree temps after sitting in the sun heat soaked and does not load up, make noise or anything!

I do not know what the original state of the system was and what problems there are that I do not know about, but it would be advisable for those with blinking ac lights to clean that electrical connector to the compressor and vacuum the system before adding any refrigerant, like I did. In the future I plan on replacing the filter dryer and orifice tube but right now I am happy to get air that is at least 75% of what factory perfect would give me.

Sorry again for the long post, but those of you that spend sleepless nights trying to decide to pull the trigger or not on a thousand dollar ac repair, will hopefully appreciate all the details I've included.

I forgot to mention that when I changed my timing belt and water pump last year I pulled tons of road sand and leaves out of the space between the radiator and ac condensor.

For those of you not versed in ac parts, the condensor looks like a small radiator itself. Maybe a lot of these older cars are losing their cooling efficiency due to obstructed airflow more than anything. 10-15 years of road debris added up to a nearly half blocked off condensor on my car.

If you look down between them with a flashlight you might think you are clear, but when you take the radiator out you will find a dark mash of broken down plant debris and road dirt caked into all the fins. Maybe a long dowel would be good to probe down there and see what you feel and what comes out caked on it when it is pulled out. Just an idea so you can check before removing the radiator.