Anyone Here Doing Their Own Auto AC Work???
- Thread starter seagiant
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Kaizen
Well-known member
Yup. I had all 3 cars get ac issues so I got the gauges and vacuum pump. Also got a kit of ac green gaskets in line cause impossible to find locally? I’ve dye and flashlight, and a smeller thing which was a last resort to find a leak
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Kaizen
Well-known member
Yea. Might take me twice as long as the pro’s but my time is free. I did have one that would not seal no matter what so I added stop leak and filled it. So far so good.
It’s intimidating as if you screw up you vent it but once you vacuum and fill one time you have paid for the tools and are ahead of the game.
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frank001
Well-known member
I have replaced A/C compressors in the past.
The A/C in my Ford Ranger started blowing increasingly warmer air a couple of weeks ago. Today I replaced the high pressure line from the compressor to the condenser that had a leak, vacuumed the system and recharged with freon. Now getting 45deg air from the vents.
The A/C in my Ford Ranger started blowing increasingly warmer air a couple of weeks ago. Today I replaced the high pressure line from the compressor to the condenser that had a leak, vacuumed the system and recharged with freon. Now getting 45deg air from the vents.
Raisedonadeere
Well-known member
I have done an old Mercedes 240D compressor seal replacement, 1985 BMW 318I freon 12 to 134A conversion, 1994 Dodge Cummins truck complete rebuild after evaporator went bad in dash and eventually ruined the compressor, Also 1996 Ford Mercury Marquis, compressor change. Did the Mercedes with out a vacuum gauge, it ran for four years till engine blew, bought a vacuum pump and gages for the rest, and all projects paid big dividends. Do a good job of sourcing parts and you can do a complete rebuild for a few hundred. compared to thousands to have done.
I again used the vacuum pump and gages to install two minisplits and two hvac systems for my sons. I think all in all the vacuum pump might be my biggest payoff diy tool off all.
I would have been in trouble a time or two if I hadn't understood the refrigeration cycle, and the pressure/temp curves of the refrigerant but now days the basics can learned in various books and youtubes available.
Installing a New HVAC in my house in 2007, I had trouble making my readings come out right on the heat cycle and the pump made a growling noise on coldest days indicating possible incorrect charge. Gave up on adjusting the readings and evacuated the refrigerant using tank in dry ice method, captures over 99 percent of refrigerant. Bought a refrigerant scale, about $100 and weighed in the correct amount and purred like a kitten for the 10 years I owned that house.
Basically you don't need gauges for a minisplit. They come correctly charged if you buy matching components and if you get a leak you just evacuate and weigh in the correct amount after leak repair, and vacuum pumped. A scale pretty much takes away the need for gauges on cars as well except when topping off or diagnosing troubles.
I have been lucky in that I never got into a part not working and needing warranty. I had my anxious moments with that $3500 HVAC with the compressor growling. The scale saved me on that one and gave me confidence on other projects knowing that I didn't have to be expert in getting the gauge readings right.
I again used the vacuum pump and gages to install two minisplits and two hvac systems for my sons. I think all in all the vacuum pump might be my biggest payoff diy tool off all.
I would have been in trouble a time or two if I hadn't understood the refrigeration cycle, and the pressure/temp curves of the refrigerant but now days the basics can learned in various books and youtubes available.
Installing a New HVAC in my house in 2007, I had trouble making my readings come out right on the heat cycle and the pump made a growling noise on coldest days indicating possible incorrect charge. Gave up on adjusting the readings and evacuated the refrigerant using tank in dry ice method, captures over 99 percent of refrigerant. Bought a refrigerant scale, about $100 and weighed in the correct amount and purred like a kitten for the 10 years I owned that house.
Basically you don't need gauges for a minisplit. They come correctly charged if you buy matching components and if you get a leak you just evacuate and weigh in the correct amount after leak repair, and vacuum pumped. A scale pretty much takes away the need for gauges on cars as well except when topping off or diagnosing troubles.
I have been lucky in that I never got into a part not working and needing warranty. I had my anxious moments with that $3500 HVAC with the compressor growling. The scale saved me on that one and gave me confidence on other projects knowing that I didn't have to be expert in getting the gauge readings right.
Robert Haas
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I just built an entire system including fabricating new lines from a "kit" bought my own crimping tool too. Pretty simple stuff actually.
bczygan
Well-known member
Never vent to the air.
Get proper training.
Bill (Trained and certified)
Get proper training.
Bill (Trained and certified)
75gmck25
Well-known member
It really depends on the age of the system. If you are resolving leaks and recharging an original R134a system the primary tools you need are a vacuum pump and a good set of gauges. OEM hoses are available from many sources, and replacing the receiver/drier and other parts is fairly straightforward. You just need to follow directions, including the recovery of refrigerant from the systems. In most cases you just weigh the refrigerant and put in the required amount. Sight glasses and looking for bubbles are a thing of the past.
If you are trying to retrofit an old R-12 system to R-134a it gets more complicated.
- In addition to the change in refrigerant, the lubricant/oil in old systems was mineral oil or ester oil, while new systems use PAG oil. If you use the newer oil it will work fine, but the oils don't mix well, so you have to flush the system and the compressor to get the old oil out.
- Many folks with CCOT systems will change the orifice when switching from R-12 to R134a. In my GM system its common to switch from a GM white orifice to a Ford blue orifice, since the smaller orifice works better with R134a.
- If your old condenser is large it might work with R134a, but most new systems use a Piccolo condenser or a parallel flow condenser (more effective) instead of the older serpentine tube condensers. Universal parallel flow condensers are easy to find, but the fittings are probabley a different size than your original condenser. This means finding an A/C shop for custom hoses, or making an adapter.
- The required charge of R-134a is about 75-80% of the R-12 charge, so you will have to watch gauges carefully and pick the optimum charge. Its not an exact science.
Bruce
If you are trying to retrofit an old R-12 system to R-134a it gets more complicated.
- In addition to the change in refrigerant, the lubricant/oil in old systems was mineral oil or ester oil, while new systems use PAG oil. If you use the newer oil it will work fine, but the oils don't mix well, so you have to flush the system and the compressor to get the old oil out.
- Many folks with CCOT systems will change the orifice when switching from R-12 to R134a. In my GM system its common to switch from a GM white orifice to a Ford blue orifice, since the smaller orifice works better with R134a.
- If your old condenser is large it might work with R134a, but most new systems use a Piccolo condenser or a parallel flow condenser (more effective) instead of the older serpentine tube condensers. Universal parallel flow condensers are easy to find, but the fittings are probabley a different size than your original condenser. This means finding an A/C shop for custom hoses, or making an adapter.
- The required charge of R-134a is about 75-80% of the R-12 charge, so you will have to watch gauges carefully and pick the optimum charge. Its not an exact science.
Bruce
I moved from NY to Florida, before moving all I knew about AC was turn it on and off, fan speed. What I quickly learned in Florida is most AC people are not only incompetent but crooks as well. Now there are good honest people around but they are hard to find.
So anyway I now own about $800 worth of AC tools which have paid for themselves many times over. I do my own car repairs and had an estimate of $10,000 to $12,000 to install mini splits in my house. Cost me less than $4,000 to do it myself!
I do take the vehicles in for evacuation if needed, not worth the investment in equipment to DIY.
So anyway I now own about $800 worth of AC tools which have paid for themselves many times over. I do my own car repairs and had an estimate of $10,000 to $12,000 to install mini splits in my house. Cost me less than $4,000 to do it myself!
I do take the vehicles in for evacuation if needed, not worth the investment in equipment to DIY.
theoldwizard1
Well-known member
One thing to watch out for is most modern cars have multiple "safety" switches that will not allow the compressor clutch to engage until everything is "right". I you don't have access to a wiring diagram, you are just shooting in the dark.
Also most automotive A/C system do not use a thermostatic expansion valve (TXV). They just have an orifice. The system is cycled on and off usually be the engine control module (ECM).
Last newer cars now use R-1234yf refrigerant. This stuff is INCREDIBLY expensive ! Plus a can only holds 8 oz not 12 oz ! Of course, your old gauge set will not work with theses systems.
Also most automotive A/C system do not use a thermostatic expansion valve (TXV). They just have an orifice. The system is cycled on and off usually be the engine control module (ECM).
Last newer cars now use R-1234yf refrigerant. This stuff is INCREDIBLY expensive ! Plus a can only holds 8 oz not 12 oz ! Of course, your old gauge set will not work with theses systems.
Last edited:
p00p
Well-known member
I service all my own r12 & r134a as well as r22 stuff.
p00p
Well-known member
Dye has only worked to find the smallest of small leaks ime.
Jeepster04
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Ive had good luck working on systems that have never been touched. Its certainly not rocket science but I would like to have a tank of nitrogen to check for leaks. This isnt recommended at all and its gets a lot of hate, but I have used shop air to find leaks. If you replace the accumulator/dryer it ‘should’ be perfectly ok. Ive had leaks not show up under vacuum but they do under pressure. Youve got to realize that there is only at max, 14.7psi trying to get in the system when its under vacuum... Under pressure its over what my air compressor puts out, so I just max it out.
Ive yet to figure out how much oil to put in once a leak is fixed. To do it 100% correct you would need to flush everything, drain the compressor, and replace the accumulator/dryer. Ive never heard of someone doing this.
Ive got one vehicle that has way too much oil in it and I think its hurting the performance but idk how to fix it. When you simply put the gauges on it, oil spits out just from pushing the quick connects on. Im wanting to try to disassemble the system and flush everything.
Ive yet to figure out how much oil to put in once a leak is fixed. To do it 100% correct you would need to flush everything, drain the compressor, and replace the accumulator/dryer. Ive never heard of someone doing this.
Ive got one vehicle that has way too much oil in it and I think its hurting the performance but idk how to fix it. When you simply put the gauges on it, oil spits out just from pushing the quick connects on. Im wanting to try to disassemble the system and flush everything.
toyotadriver
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LS6 Tommy
Well-known member
Always have since around 1980. Both daily drivers are under warranty, so I'm only going to do the Malibu when the time comes.
Tommy
Tommy
LS6 Tommy
Well-known member
Banjorear
Well-known member
This. Got all mine from Harbor Freight. Bought the "deluxe" vacuum pump and it works great. Dive in. If it's broke, you're not going to do more damage, so why not?
ford33
Well-known member
I have done my own automobile AC work for the last 5 years. Replaced an entire AC system on a Chevy van two years ago. Not that difficult as long as you understand how the system operates. Understanding basic theory and you will have a good foundation for interpreting your gauges and understanding temperature and sources of trouble. It is not about finding leaks. It is important to know pressures, temperature and operation of the system. All easily learned.
Get a good set of gauges, a vacuum pump and the specifications for the car you are repairing. Wear safety glasses and be careful when working on the high side pressure lines.
I use green dye and a light for spotting leaks. Works very well also long as you don't smear the dye on the hoses and fitting when working on them. I change to new latex gloves when inputting the dye and then throw them away when done. I don't want the dye on fittings and hoses.
Get a good set of gauges, a vacuum pump and the specifications for the car you are repairing. Wear safety glasses and be careful when working on the high side pressure lines.
I use green dye and a light for spotting leaks. Works very well also long as you don't smear the dye on the hoses and fitting when working on them. I change to new latex gloves when inputting the dye and then throw them away when done. I don't want the dye on fittings and hoses.
86turbodsl
Well-known member
Yes, R12, R22, R134 and various combinations of other compounds. MVAC 608 and 609 certified. It will save money in the long run, but the equipment to do it right can be spendy.
theoldwizard1
Well-known member
Neighbor own a HVAC shop. Case of beer.
motofool33
Well-known member
i bought a a few machines off facebook market, more geared towards home AC kept enough to do mine, evac machine ordered a tank, have the vacuum pump and guages. you could buy all new for around 1000$ and the labor to do the ac compressor was atleast that on the car i was working on