if i can still get r12 put back in my system, then that's what i want. my van is a dark blue, and when it was about 90 outside, my van was about 120 inside last summer. when my ac system worked, it was literaly like some one had left the door open on a commercial freezer in my car. it worked THAT good.
I'm thinking I need to overhaul my AC system next summer. I have a friend who has some vacuum equipment that can suck out and store the existing coolant, and pump down the system afterward. But we've never flushed the system before. There must be another machine that does the flushing? If we can't get that, is there a way that a backyard mechanic can do this?
if i can still get r12 put back in my system, then that's what i want. my van is a dark blue, and when it was about 90 outside, my van was about 120 inside last summer. when my ac system worked, it was literaly like some one had left the door open on a commercial freezer in my car. it worked THAT good.
If you replace the condensor when the system is being serviced, use a new condensor made for R-134a and it will work just as well as R-12. Also replace the orfice tube with one made for hot weather R-134a. R-134a is a good refrigerant, and it will cool the interior very well IF you have the right condensor. My '94 came factory equipped with R-134a and it works very well in the summer here in Utah. The only exception is stop and go traffic in southern Utah. Can't get enough airflow through the condensor at low speeds to be effective at all. I will be installing a pusher fan that turns on when the AC is activated this summer to address that issue.
If you replace the condensor when the system is being serviced, use a new condensor made for R-134a and it will work just as well as R-12. Also replace the orfice tube with one made for hot weather R-134a. R-134a is a good refrigerant, and it will cool the interior very well IF you have the right condensor. My '94 came factory equipped with R-134a and it works very well in the summer here in Utah. The only exception is stop and go traffic in southern Utah. Can't get enough airflow through the condensor at low speeds to be effective at all. I will be installing a pusher fan that turns on when the AC is activated this summer to address that issue.
Totally agree, but...
Swapping in a new condenser can get tricky, though. It's not a bolt in swap, the line connections are different. Then there is still the wheezing out at low speeds. That's where R134a falls short in dual systems.
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Hey all, I got an A/C question; but first I want to give a little description of my van.
1992 2WD 3.0L Shorty with NO rear heat/air vents, just front.
The van was bought new in 1992 and in 1999 my father took it in to get fitted for 134a. Shortly after the A/C went out and he took it back and the shop replaced all the lines and components for $1500. Well after about 1 year it went out again and from then on the Aero has been without A/C.
Since then the van has been handed down to me and since this thing is mechanically perfect in every other way i figure why not try to get the A/C fixed. I have never done anything to it because my father just told me the system was faulty and its not worth it; and i believed him thinking we would be getting rid of this thing once it dies but I'm a poor college student and i just like the van so much i want to get everything working again.
So today I got my gauge out and hooked it up to the system and it read 25 PSI. I was SHOCKED; and that gave me some hope that the system can still hold a charge after all these years!!!
Now also when I turn the A/C on the compressor doesn't kick in at all, so I'm thinking the switch that controls the compressor is broken. The only thing I noticed kick in was the high idle and thats it.
I plan on taking it to my mechanic Monday but If anyone here has any opinions all are welcome!!!
I think 25 psig is too low to activate the pressure switch, and usually indicates that most of the refrigerant has leaked out. I would have an AC tech check the system for leaks.
Q: "Can I do it?" Yes, given sufficient time, knowledge and money.
It would appear your dad already paid for the essential (costly) parts needed to convert to r134a. With some minor tinkering, you should be able to get the system up and running again. Given the system crashed twice already is a little worrisome....especially if the shop specialized in A/C repairs.
Its not rocket science but A/C work does require a good working knowledge of how the various components function together. There is enough help on this forum to help you along the way. If your system just lost refrigerant charge each time it went down in the past, it may something as simple as changing/replacing the o-rings in the various quick connect fittings. Since the shop replaced the lines I would think they would have done this already. It is also possible they did replace the o-rings but mangled a quick connect fitting, causing it to leak. You (or a shop) can recharge the system with a special fluorescent dye mixture. Leaks are easily revealed by using a small blacklight flashlight. Leak kits are available at auto parts stores and Walmart. They have a can of refrigerant/dye, blacklight pen and yellow goggles to make it easier to spot the leak.
As mentioned already, if the system pressure is too low (leaked out) the compressor will not operate. You can test for compressor function by disconnecting the switch at the accumulator and then putting a jumper wire across the two leads of the connector. (You need the engine running and the A/C dash switch to the 'ON' position when doing this.) When you jumper the connector, the compressor should kick in. Test for no more than a few seconds to confirm the compressor operates. Letting it run with no system charge will damage the compressor.
If you still feel like tackling this yourself, start here and post back with your findings. Doing some reading on this topic from previous postings would also be helpful.
As Aerocolorado said, if the compressor was off and you read 25 psi, the system is nearly empty.
However, it sounds like you are using the cheap low side gauge on a can of refrigerant from the parts store. Those things are notoriously inaccurate and I'm wondering if yours isn't just way off base, here's why:
You mentioned that the idle jumps up when you turn on the AC. Normally, when the compressor kicks on, the pcm bumps up the idle to compensate for the load. If the system pressure is too low to close the cycling switch (~45psi), the compressor won't engage AND the PCM won't bump up the idle.
If the system was nearly empty, the idle wouldn't jump up when AC is called for. It sounds like there is at least enough system pressure to close the cycling switch. That's assuming the AC is factory installed, aftermarket could be different.
It's possible that you may just have a clutch issue with the compressor.
Try turning on the AC (engine running) and tap the face of the compressor clutch with a broom handle, screwdriver handle or similar object. See if the clutch engages then.
-If it engages, you need to adjust the clutch gap and troubleshoot from there.
-If it doesn't engage, check for power and ground at the AC clutch connector.
Report back what you find.
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OK, I took my van to my mechanic today and he charged my system and I turned the air on and the compressor never kicked on, but like I said before the high idle kicked on. So he said theres a clutch issue and my best bet would be to get a new compressor or go to a bone yard and find one.
Now the only thing I want to know is that since my system is charged is there something I need to do to the system before I remove the compressor? I know the dangers of working with refrigerant and I just want to be safe rather than dead under my aero trying to replace the compressor.
Also is there a specific compressor that is reliable that I should buy instead of an OEM, OR is OEM just fine?
OK, I took my van to my mechanic today and he charged my system and I turned the air on and the compressor never kicked on, but like I said before the high idle kicked on. So he said theres a clutch issue and my best bet would be to get a new compressor or go to a bone yard and find one.
Now the only thing I want to know is that since my system is charged is there something I need to do to the system before I remove the compressor? I know the dangers of working with refrigerant and I just want to be safe rather than dead under my aero trying to replace the compressor.
Also is there a specific compressor that is reliable that I should buy instead of an OEM, OR is OEM just fine?
From my previous post: "It's possible that you may just have a clutch issue with the compressor.
Try turning on the AC (engine running) and tap the face of the compressor clutch with a broom handle, screwdriver handle or similar object. See if the clutch engages then.
-If it engages, you need to adjust the clutch gap and troubleshoot from there.
-If it doesn't engage, check for power and ground at the AC clutch connector."
Your clutch gap is probably too wide. That's a very easy ($0-10) fix.
Even if the clutch coil has failed, it's not necessary to replace the compressor. A clutch kit is about $100 and easy to install. A good reman compressor is $200 or better. (The cheaper ones are a quality crap shoot).
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woah back from the dead. i need to start visiting this place more often again. i still wish the fittings were like on my civic (all standard nuts, go at the fittings w two 19mm box end wrenches.)
so does any one know HOW to pull the fittings apart? i may have to go to the j/y this week and tinker around on another 'star. i found out that harbor freight sells vacuum pumps, and when used correctly then DO properly evacuate the system so one can properly re charge it.
although i am currently jobless, i STILL am wanting to tackle this project, as I have been spending time fixing all problems on my star and am getting it all fixed up (going to be replacing all rocker panels this summer, giving it a drop in the front and am looking at some cobra rims for it. also planning on a nice system upgrade including some dvd monitors and new(er) carpeting and what not)
" i found out that harbor freight sells vacuum pumps, and when used correctly then DO properly evacuate the system so one can properly re charge it."
If you're talking about the air operated venturi type, don't waste your money. They DO NOT work well enough to remove moisture from an AC system. To even get close, you need a massive volume of compressed air. Even then, they don't pull down to a micron level suitable for recharging. You need at least a 5 cfm electric vacuum pump to do the job.
although i am currently jobless, i STILL am wanting to tackle this project, as I have been spending time fixing all problems on my star and am getting it all fixed up (going to be replacing all rocker panels this summer, giving it a drop in the front and am looking at some cobra rims for it. also planning on a nice system upgrade including some dvd monitors and new(er) carpeting and what not)
Good Luck
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Hate to continue to dispute the assertion that vacuum venturi pumps (Harbor Freight) do not work, but in fact they do work and very well. Caveat: You need a constant source of vacuum and many smaller shop compressors cannot provide this. I used two 20 gal compressors linked together before the venturi pump and was able to easily pull down the required vacuum and hold it for the 30 minutes required to evaporate all moisture from the system. As they say, "You can't argue with success" and this A/C system has been operating 6 years now without a hitch.
re: quick connect fittings. Even with the proper release tool they can be stubborn to get apart. Mostly this is due to lack of access to be able to get a good tug on the two components. The fitting that gave me the most "fits" was the lower one going into the condensor. No room at all. A good (i.e. not Chinese made) small sized (3/8-1/2) inch worm drive clamp placed just behind the rear fitting can be used as a pry point. A small block of wood to protect things on the condensor/radiator side and a long lever/pry used against the worm clamp will allow you to manipulate the release tool with one hand while prying in a backwards direction with the other.
Release tools: Come in a variety of materials and prices. Pro shops need the high dollar tools but a DIY'er can get by with the plastic/nylon variety found in most parts stores.
You are trying to displace springs that have accumulated years worth of fine road grit within a tight housing. As such, they are not inclined to "give" that crucial amount necessary to permit easy disconnection. Several judicious applications of WD-40 or similar will help wash out much of that grit and dirt.
New o-rings are a must. If converting to r134a, a different type ring is required. Its a light green in color. There are different sized hoses involved as well. You can buy a pre-packaged box of properly sized o-rings and new springs for the connectors from Arizona Air (ackits.com) or try the local parts store.
Getting the quick connects back together is almost ridiculously fun. They connect so easily you, at first, tend to think they aren't going together correctly.
Last edited by aerocolorado; 06-24-2009 at 12:27 PM.
Reason: add details
"Hate to continue to dispute the assertion that vacuum venturi pumps (Harbor Freight) do not work, but in fact they do work and very well. Caveat: You need a constant source of vacuum and many smaller shop compressors cannot provide this. I used two 20 gal compressors linked together before the venturi pump and was able to easily pull down the required vacuum and hold it for the 30 minutes required to evaporate all moisture from the system. As they say, "You can't argue with success" and this A/C system has been operating 6 years now without a hitch".
I won't argue, except to say that there is a huge difference between 750-850 micron level on a venturi pump and the needed <100 microns for proper ACevacuation and moisture removal. Caveat Emptor.
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