I had to replace a bad hose so now AC has to be charged. Something I can do at home with a kit? I do happen to have a vacuum pump I was given. The one place I knew I could go closed after 75 yrs, bummer.
Yeah, you can do it at home, but you need a bunch of stuff. You will need that vacuum pump, and a set of manifold gauges. I pressure test my systems with Argon after I vacuum them out. Then vacuum them again. Then you will need the refrigerant. Once you get all of the fixins, you might be near what a shop would charge to handle it.
Do you know how much refrigerant and what type it uses? You can get a charging hose at an auto supply but unless you know how much the system holds you need to know what you are doing and need to monitor the high and low side pressures to get it right or you will damage the compressor.
Thanks!! I just got my phone in hand to google and saw your post. I forgot they are still in business! I will call them Monday.
From my experience if you use a vacuum and the system will hold vacuum after you shut off the pump it will not leak. As far as charge stop when the low side hose starts to get cold about half way between the firewall and the compressor.
As a licensed HVAC-R contractor and business owner with many decades of experience, i would only recommend pressure testing anyA/C system with dry nitrogen. (*** never pressure test anyA/C system with air or oxygen). after all repairs are completed pressure test A/C with dry nitrogen over night and if the test fails to hold over night there's more leaks, never connect a vacuum pump to a system that did not pass the pressure test if you connected a vacuum pump to an A/C system with leaks it will pull moisture into the system the whole time your vacuum pump is running. as a fellow car guy from CT. I will gladly try and assist as much as possible to help get your system operating properly.
As above... dry nitrogen only. Moisture is the hardest contaminant to shift from a refrigeration /ac system. Air contains moisture and it only needs a small amount to cause havoc in a system. If you are changing any component keep all ends plugged to prevent any moisture or dirt getting into the system. The oil is hygroscopic and attracts moisture.Also fit a new filter drier as a matter of good practice. Old systems sometimes had a sightglass where you could trickle charge the refrigerant until clear but it’s much better to check the data plate for the type and weight of charge for the system and then weigh it in. I would suggest that you have a shop do it properly. It’s actually illegal here to handle refrigerant without a certificate/exam test so you have to go to a proper outlet. If you are intent on doing it yourself wear eye and hand protection.... a refrigerant burn is nasty.
I've always cringed at do it yourself refrigeration service. Refrigerant is dangerous stuff. A drop of liquid refrigerant on your skin is instant frostbite; a drop in your eye and you are blind. My advise is to take it to a professional.
I have been doing AC recharges here at home for probably 40 years. Used R12 until it got hard to get, then switched many systems over to R134A. Always change the dryer when you open a system, oil the O rings before you hook up the connections to keep from cutting them and to help them seal quickly. It's better if you have a manifold gauge set so you can keep up with the pressure on high and low sides. I pull a vacuum for 30-45 minutes, shut it off and close the valves, let it set for 30 minutes, if the gauges don't change, it will hold a charge, if they slowly creep up to 0, then you have a slow leak. Always charge into the low pressure side. For most units, 3-12OZ cans will fill a system, a larger system like a dual system on vans might take 4-5 cans. It's not rocket science to recharge a system, just follow directions and use caution. Some kind of eye protection, gloves will help if any refrigerant leaks on your hands. Lots of voodoo tales about AC systems out there, read up on it and you'll see it's not that hard.
Scary stuff Freon more scary propane likes in your barbque grill just as cold and will burn. Farmers will tell you the really scary stuff anhydrous ammonia And you do not need a certification for the last two.
Thanks for all the input fellows! Here is some back round. I built the whole [134a] system using parts from Vintageair, Aeroqui$$ lines and fittings per Vintageair instructions. My friend that had a repair shop filled it for me (.6#?), this was about 26 years ago. Worked excellent (35°) for about 12 years then needed a boost which I did with napa can and gauge, back to life for another 10 years and it needed another napa boost [fought me a bit] and worked fine again for about 4 years and while the AC didn't stop working one of the [small line] fittings was leaking oil [making a mess of any paint it landed on] so I figured it was just a matter of time before system would quit again. I thought to put new o ring and ferrel in the fitting but I didn't have enough extra hose length to shorten the hose to a "clean" area {not trusting self to do it right}, I guess I measured that one pretty close! So I went to local hydraulic shop. New style hose is pretty slick, can rotate the ends after they are crimped on. Just need crimp pliers like used in PEX plumbing and can do at home.
I started dealing with A/C back in the sixties with R12 and was doing it when the change to R134A came around. Not real sure what’s out there now! Back in the eighthes I had a car with a leak and the hose cost well over $100! So I just kept a case of that 85 cents a can ,R12 handy, when it quit cooling, I added a can! I guess I am responsible for a large portion of the O-zone hole! I have even cooled a can of beer with a can of R12! But we/I didn’t know it was hurting the environment then! I have converted many R12 to R134A , sometimes doing it the right way, sometimes not, with very little difference in performance! I still have a few vehicles that get a couple of cans a year! But some things I have learned over the years is it’s beneficial to leave the vacuum pump on the system for a while , the longer the better and too much Freon is as bad as too little! And small leaks can be hard to find! Just my way! Bones
Well tomorow is supposed to be rough, thanks to 1941ChevyCoupe for making a house call last week. I watched as he followed and explained his own instructions as in post #7. Held pressure test for 2 days so good to go, Vintageair gave him the weight to charge to. Many thanks Brian and to Vintageair for being responsible to old [] customer!
Wouldn't the charge amount depend on the model of Vintage Air, hose length, dryer type, condenser size, etc.? I can't imagine that a 2.2lb charge would cover the entire suite of systems they sell.
When used to charge R15 systems, there was a sight gauge and we charged until the sight glass went from milky and bubbles to clear. It would then be full. The R134A systems are completely different. There is no sight glass because R134A is always milky no matter how much is in the system. Obviously the easiest way to charge that system is with a charging station hat will evacuate, pump down a vacuum, and recharge by a given weight of refrigerant read from a sticker on the system or a repair manual. If there is no known charge for it, then there are charts that will give high and low pressures based on ambient temperature and interior outlet vent temperature measured at the center vents. Once those parameters are met, the system is properly serviced. A/C books and the Web can give you those charts. DON'T service the system by using a can and hose bought at the local Autozone! Some R134A systems can fail if under or overcharged by as little as one ounce. When I worked automotive sometimes I did tune up, A/C, and electrical. Usually in the desert. Summertime I was booked solid for weeks with A/C work.
It's not hard to do. Need the right tools and knowledge. The last part is where many are not as prepared as they should be. A/C systems are pretty straightforward in the mechanical sense. Basic systems like Vintage Air are electrically simple as well.
1 lb 12 oz. Gave Vintageair the compressor model, evaporator model and condenser style and maybe size. VA probably has my original purchase of parts for system on record. Yes there is a sight glass and it does get clear when proper weight of refrigerant is used and system pressure is in spec. Ac air is about 35° right at out put of evaporator.
After some research Vintage Air states their standard charge with R134 is 1.8 lbs and additional may be needed for trunk mount or if liquid line is over 12 feet.
The last time my VA was recharged to 1.75 lbs. Pretty close, but my guy had to guess based on experience. I need to check the vent temp this week to see if my charge is ready for Bowling Green, where it is always HOT. Thanks
Now mind you I am not recommending this , it is just what I have done , well forever, R12 and R134A. I have never been to A/c school , just a few seminars. I have probably “ serviced “ over a thousand units, from foreign to high dollar American cars, in my career! Every time the folks didn’t want to spend a huge amount of money that was quoted from a A/C place! Sometimes $750+! Just working folks that were trying to get along. I grab my gauges and see where the system is at, if it is not cooling and the pressures ate low, I put a can in it! Then check the temperature by hand or gauge, depending where I’m at! Usually the pressures will come up to somewhere right and the system will start cooling and I am done! $20 instead of $200+. Customer/ friends were happy and not broke and I had some beer money! I have done many other work on A/C systems, but this was my fix 90% of the time! I have never run into an A/C system that was so fragile that one ounce would damage it! Again, just my way! Bones
Customer waiting, needs A/C line, very few if anyone around here is going to pressure test a car overnight, a couple of lbs of R134a just isn't that expensive yet............................
Me too Bones. Been there and did the same thing the same way. You happen to get a bit too much in one, the popoff will purge it. Same if the expansion valve or orifice tube gets stopped up. Too little, it will only peewee cool. Poor folks have poor ways, and I've been poor before...
When in doubt on how much freon to add on a low system I have always went with stop when the low side hose gets cold about 18 inches from the compressor. That is on a system that is trying to cool.
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