A/C not blowing cold. Charged w/ All New Parts

[sam.basye]

Just to get the proper terminology here, evacuation is vacuuming the system down after the system is recovered. The machines they use do multiple things. Some are more "complex" then others but the basics are three functions, recovery, evacuation, and recharge. During recovery, the machine uses a compressor to suck the refrigerant out to a certain level of vacuum, usually around 13" Hg. Some more complex units monitor the weight of the refrigerant going into the recovery bottle with a scale and stop sucking when it sees no more weight being added to the bottle. Most units, you just stop recovery manually for the same reason. Now the whole recovery process is not needed if the system is empty, and the tech can go right to the evacuation process in which a deeper, longer vacuum is attained (29.9"Hg with a loss of 1"Hg for every 1000 ft of elevation) It is also at this point that any part replacement would be done and any oil be added (if your adding oil manually. Some machines have oil injections units built into them that add oil after the evacuation process is done.) Or separate oil injection units are used at the same point. If doing it manually your supposed to add a certain amount of oil for each component replaced (ie 1-2 oz for a condenser replacement, 3-4 oz for a compressor, etc.) Some compressors come with oil in them and this is usually stated on the new compressor. One other thing about adding oil manually before the evacuation process is that you could potentially vacuum out some of the oil it the system, so I always recommend putting oil in after the evacuation process.

At some point during the evacuation, the valves need to be closed and vacuum should hold on a leak-free system. If not then as 19963 said you use whatever leak detection method you use.

Now evacuation does several things. Most importantly it boils off any moisture in the system. Moisture is a system killer for many reasons I wont get into but you want NO moisture so the longer the evacuation the better. Now if the system is all new parts and has never had refrigerant in it then the evacuation process can be less. It also provides vacuum which helps suck in the appropriate freon and oil charge.

Lastly is the charge process. Most machines have a way to charge from the recovery bottle or a virgin bottle. I recommend charging with virgin refrigerant. The recovery bottle has your refrigerant and many other customers refrigerant in it. Some could have used a blend or something else (propane) so you could have a witches brew in your recovery bottle. Now some of the "complex" machines have a refrigerant detector built into them that sample the refrigerant before it's recovered. Or you can have a separate unit that does the same thing. A lot of shops do use these so they can reuse the refrigerant they recover and cut expenses.

Charging is simply programming your weight and pressing a button on most units. Some shops may use a separate weight scale and place the bottle on the scale and tare it out then use the valves on a set of gauges to stop flow once the proper amount of weight has come out of the scaled bottle. Now, I like to charge through the hi side to watch the pressure SLOWLY go up on the low side. This tells me the orifice tube/expansion valve is doing it's job. It also wont slug the suction side with liquid refrigerant which could lock your compressor up if you immediately start the vehicle after charging through the low side. Also, if you cant finish a charge (which you should be able to do if you did everything properly) then you can start the vehicle and use the vehicles compressor to pull in the appropriate charge.



Hope this explanation helps someone who would like to know what techs are doing when they service your AC system. I see a lot of questions about AC on here (especially when it 100 degrees outside) and though it might help someone (maybe even an aspiring tech) know what's going on in an AC service. There's obviously much more on the diagnostic side and learning the basics of what is actually happening in the high and low sides of the AC system helps immensely with this. But it all starts with that first hand held set of manifold gauges.

That’s some great info!

Thanks for sharing the entire process. [emoji1303]

 

[96RedRunner]

I already ordered the new condenser and the proper bolts. Both should be here by Saturday so I’ll do it all this weekend while I’ve got 4 days off.

Follow the torque spec's for the bolt's !!!, it's aluminum a lot of expansion and contraction going on at different temps and pressures.
The freon is formulated to not harm Ozone, if you decide to blow charge do it at the bottom of condensor, have a wet rag over the fitting before you loosen bolts. Wet rag will catch freon and oil, better than in the face and all over that area. It's best to do it on a at ambient temp system pressures are at their lowest.
lightly lube new O-rings before putting connections together.
[MENTION=107674]JRZEE2000TR4LTD[/MENTION] layed it out spot on, virgin freon is the way to go. I'm familiar with the machines, Tech blew smoke up ya arse with his explanation of why leak wasn't caught, you got McD'd. If he would have done right leak would have been caught job stopped, contacted you for directions of completing job. You might bring that up when you go to get it recharged.

 

[sam.basye]

Follow the torque spec's for the bolt's !!!, it's aluminum a lot of expansion and contraction going on at different temps and pressures.

The freon is formulated to not harm Ozone, if you decide to blow charge do it at the bottom of condensor, have a wet rag over the fitting before you loosen bolts. Wet rag will catch freon and oil, better than in the face and all over that area. It's best to do it on a at ambient temp system pressures are at their lowest.

lightly lube new O-rings before putting connections together.


[MENTION=107674]JRZEE2000TR4LTD[/MENTION] layed it out spot on, virgin freon is the way to go. I'm familiar with the machines, Tech blew smoke up ya arse with his explanation of why leak wasn't caught, you got McD'd. If he would have done right leak would have been caught job stopped, contacted you for directions of completing job. You might bring that up when you go to get it recharged.

That was my plan. Seemed like the most logical place to ‘relieve’ the system. It was a big surprise the first time I replaced everything. Lol
Luckily the house, wife’s car, and my car weren’t downwind as a giant cloud of refrigerant and oil blew out the wheel well from removing the manifold off the compressor. Haha. (The compressor failed on me prior which is why I replaced everything)

Happen to know those specific bolt torque specs?

Yep. I was told no leaks over the phone and that it was ready when I picked it up the first time from the service advisor. Advisor number 2 gave me that crappy explanation...

 

[Bad Luck]

F
The freon is formulated to not harm Ozone, if you decide to blow charge do it at the bottom of condensor, have a wet rag over the fitting before you loosen bolts. Wet rag will catch freon and oil, better than in the face and all over that area. It's best to do it on a at ambient temp system pressures are at their lowest.
lightly lube new O-rings before putting connections together.

R134a has since been classified as a 'high global warming potential' gas. R134 should NEVER be released into the atmosphere. For the sake of the environment and your lungs please get r134 recovered and not vented into the atmosphere. A wet rag isn't going to do anything except capture some of the oil out of the refrigerant as it escapes. [MENTION=140991]sam.basye[/MENTION]


Edit: The amount of incorrect information here astounds me. Before people start getting all defensive here I am ASE certified in HVAC systems. A large portion of my workload during the warmer months is AC work. Please recover all your refrigerant instead of venting to the atmosphere. R12, R134, and R1234YF all have different fittings to help prevent you from hooking up the wrong ac machine. Yes, it is still possible with a set of manifold gauges to charge systems from a different refrigerant source bottle.

 

[96RedRunner]

Happen to know those specific bolt torque specs?...

7 ft/lb's according to FSM pg AC-61.

 

[96RedRunner]

'high global warming potential'...

Potential [puh-ten-shuh l]
Adjective: Possible, as apposed to actual.
Noun: Possibility.

RETA [Refrigeration Engineer and Technician Association] Certification 1980 pre ASE cert, acquired ASE when it became a requirement.

I do believe in protecting the environment and myself. The amount of potential hazard induced into atmosphere from a 20 oz charge of R134A, [MENTION=140991]sam.basye[/MENTION] system leaked low charge, is equal to 2-300 cows farting in a field. Going by what the EPA has deemed 'high global warming potential'.

 

[Bad Luck]

Potential [puh-ten-shuh l]
Adjective: Possible, as apposed to actual.
Noun: Possibility.

RETA [Refrigeration Engineer and Technician Association] Certification 1980 pre ASE cert, acquired ASE when it became a requirement.

I do believe in protecting the environment and myself. The amount of potential hazard induced into atmosphere from a 20 oz charge of R134A, [MENTION=140991]sam.basye[/MENTION] system leaked low charge, is equal to 2-300 cows farting in a field. Going by what the EPA has deemed 'high global warming potential'.

I'm not going to argue with you. Feel free to post as much google information as you want eace: Bottom line is it's bad for the environment and bad for you. Every little bit helps. If everyone picked up 1 piece of trash and disposed of it properly the world would be a much nicer place in my opinion. Enjoy :bravo:

 

[jgue467]

Can't find evidence of R134a doing damage to earth's ozone layer.

... Feel free to post as much google information as you want eace: Bottom line is it's bad for the environment and bad for you....

I've tried to find web info labeling r134a as dangerous, can't find it.

Would you do us a favor and post what you have that genuinely indicates r134a damages the earth's ozone?

Here is what I found: HFCs such as R134a (used in positive pressure centrifugal chillers) have no ozone depletion potential (ODP). ... If the refrigerant is less efficient than R134a or R410A, the lower efficiency chiller will contribute more to global warming through higher energy usage, leading to increased carbon emissions.

And:

AllChem Company |*| R134a - refrigerant, which does not destroy the ozone layer

Let's spread knowledge like violence. Luck and enjoy those Runners. :cowboy:

 

[LittleCaesar]

My 02 cents, though I am no expert.

One of my BILs is a chemical engineer. He told me that 134 is bad for the environment, given that it is Carbon based. But in reality everyone in a 200 home subdivision could release all their r134 at the same time into the atmosphere and its effect on the ozone is equivalent to a non DEF diesel truck operating for about five minutes or so. If one has the ability to capture refrigerant, by all means do so.

In order to ride the good wave of non carbon based refrigerant, auto makers are now using r1234. Supposedly it has a much low global impact score of 150 for a 24oz can versus 1450 for a can of 134. But 1234 is flammable, though a slow burn, but should make some lawyers well off sometime in the future.

 

[96RedRunner]

[MENTION=319302]Bad Luck, google is your friend unless maybe in your case you have the latest MSDA sheet on file. The MSDS sheet refers you to the Kyoto Protocol, neither says any thing other than may or potential hazards to ozone and greenhouse gases.
I agree all should be done to protect environment, I was young when you could'nt swim in great lakes or eat the fish.
If the science behind global warming climate change what ever you call it was'nt so scewed for a purpose I would be more concerned with this subject. I can look back over last 50 years at what science has said would happen, that hasn't and know that some are full of chit. More so now that it involves way more money for these so called scientists.

 

[Bad Luck]

I've tried to find web info labeling r134a as dangerous, can't find it.

Would you do us a favor and post what you have that genuinely indicates r134a damages the earth's ozone?

Here is what I found: HFCs such as R134a (used in positive pressure centrifugal chillers) have no ozone depletion potential (ODP). ... If the refrigerant is less efficient than R134a or R410A, the lower efficiency chiller will contribute more to global warming through higher energy usage, leading to increased carbon emissions.

And:

AllChem Company |*| R134a - refrigerant, which does not destroy the ozone layer

Let's spread knowledge like violence. Luck and enjoy those Runners. :cowboy:

From your article: "potential of global warming (PGW) of carbonic acid is 1 300, which is much more lower than the PGW of R-12, which is 8 500"

Exposure to r134 can cause lung damage, nerve damage, etc. Feel free to look that up on your own.

Edit: I also never said it was bad for the ozone, just the environment. Just to clear that up as well.

 

[sam.basye]

Well, I haven’t bothered checking the temp from any of the vents, but I’d say it’s probably within 5° of ambient now. Considering it’s been in the low 90°s this weekend, it’s hot!

I have the new condenser and bolts ready to go, but waiting to do it until the day I can have it recharged.

Considering the A/C is basically useless at this point is it safe to assume most of the contents have left the system? Depressurized? The condenser is all wet near the leak.

It’s gonna be a miserable 3.5 hr drive to work Tuesday or Wednesday w/ a high of 96°/97°... Lol

Also, should I replace the drier/accumulator?
I have a spare one I originally bought from the dealer, but it’s not a Denso or should I buy another Denso from rock auto ($10 + shipping) or just leave it?

 

[JZiggy]

Avoiding contact with fluorocarbon material in gas phase is always a good idea. Releasing it into the atmosphere is not good for anybody. Don’t care if it’s R134a or R12.

 

[Bad Luck]

Considering the A/C is basically useless at this point is it safe to assume most of the contents have left the system? Depressurized? The condenser is all wet near the leak.

Try turning your ac on and looking at the ac clutch. Judging by your description of the oil I would guess it won't turn on. If the ac clutch engages then there is still enough refrigerant in there to recover. If the clutch isn't engaged then you probably only have an ounce or two in there.

 

[96RedRunner]

Also, should I replace the drier/accumulator?
I have a spare one I originally bought from the dealer, but it’s not a Denso or should I buy another Denso from rock auto ($10 + shipping) or just leave it?

96Red's drier 320k mi never changed it. Desiccant cartridge inside drier broke into zillion pieces, required replacing everything in system. A $30 part tuned into $1100.00 in parts PITA job. On my 01 I changed it at 200k along with condensor.
I would say your good with what you have, change it.

 

[sam.basye]

96Red's drier 320k mi never changed it. Desiccant cartridge inside drier broke into zillion pieces, required replacing everything in system. A $30 part tuned into $1100.00 in parts PITA job. On my 01 I changed it at 200k along with condensor.
I would say your good with what you have, change it.

I installed the current one only 3 weeks ago with a new Denso, but I’ve read anytime the system is opened up the drier should be replaced.

 

[96RedRunner]

I installed the current one only 3 weeks ago with a new Denso, but IÂ’ve read anytime the system is opened up the drier should be replaced.

That's different then, 3 weeks old I wouldn't change it. I've heard that also haven't followed it, it's a situational decision. The short amount of time you had it open and being new I don't see a problem. If I was the Tech doing job I would let vacuum pump run a bit longer to pull moisture out, air doesn't take as much time.
The Tech should know this, shoot the chit with tech n mention extended Vac time, hand him a $20. ha

 

[LittleCaesar]

I wouldn’t worry about replacing the new drier.

Vacuuming is imperative to removing moisture in the system.

Ever consider moving closer to work? That is a long drive.

 

[eanema]

I would somewhat disagree, although it would depend on the exact situation. Dryers work like the silica desiccant packages; they absorb water by chemically reacting with it. No amount of vacuuming will remove the water. But if the refrigerant was exhausted into the atmosphere, or less optimally, the air is dry when you break the vacuum (and the air is sucked into the system) less of the silica desiccant will react with the moisrure in the air.

Basically, it's a $20 part and hopefully you will never have to do your AC again, so do it right and don't worry about getting moisture in your AC system. Moisture in the system can freeze in the expansion valve and deteriorate the oil in the system preventing proper lubrication. And probably other things I don't know about ;-)

$0.02

Sent from my Pixel 2 using Tapatalk

 

[sam.basye]

I’ll take a look at the drier and see how much work it’ll be to replace. Lol While I think it’ll be fine, there will always be that feeling of doubt until I get it recharged.

Of the entire job, the condenser was the biggest PITA to replace the first time. Moving the radiator back, having to cut the condenser input block off from frozen bolts and squeezing it down through the bumper support, and my light bar brackets being in the way and a pain to access. Lol

Just about finished with one side of the dog rear seat cover tonight! Took longer than I expected.

I only have to drive to and from work about once a week so it’s doable for now. That’s assuming I have working A/C. Haha

Still trying to figure out when it’s most convenient to do the work and when I can bring it in so the system is depleted the least amount of time.