Please School me on A/C Tools

[HawkRod]

I need to work on the A/C systems for at least two different cars. I am tired of (a) leaving my car with unknown shops and (b) paying big dollars for A/C work. So I want to get the tools I need so I can work on A/C repairs myself. Previously, I have just shoved cans of R134a into the system with one in-line gauge. I need to step up my game.

Can you help me get a good list for the A/C tools I need?

I went quickly to Summit Racing to spec out a couple of things.
First, I need a good set of gauges. Something like this? I like that it has a case to keep it neat and tidy when I don't use it.

Then, I guess I need a vacuum pump. Like this?

Obviously I need cans of R134a (mine has been converted).

Any feedback on my tool choices? Additions? Replacement? Subtractions? Any feedback is appreciated!

Thanks,

Hawk

 

[PlymCrazy]

I'm literally in the same boat right now for the newer vehicles I own.

 

[sam dupont]

A friend of mine uses a 12 volt vacuum pump. I believe it is actually a compressor from a GM car. It looks like hell with wires and pieces hanging loose, but he does over 50 repairable a year, most are front end. If you don't want to spend $200+, it must not take much to pump the systems down. He fills with the cans from the box stores. Some have a gauge on them.

 

[Darter6]

Those will do just fine .Buy yourself a GOOD can tapper or invest in a bottle of R-134.
Then a scale to weigh the bottle if your systems do not have a sight glass.
Robinair has been around for a long time.So the pump should last you a life time.

 

[WileERobby]

EPA Regulatory Requirements for MVAC System Servicing | US EPA

 

[Lefty71]

Forget cheap universal gauge sets. Get one from Robinaire, Ritchie or other major brand if you want plain ones. I personally would recommend you get a good set from the start; like this Testo 550;

Testo 550s Basic Hose Kit - Smart Digital Manifold with Wired Temperature Probes and set of 3 Premium Ball Valve Hoses

At first this will look daunting, but understand that they do all the thinking for you...no need for you try and interpret the data....running evap and condenser temps are interpreted for you and displayed right in front of you as you work. Same kit for 60 different refrigerants. BTW, you wont need your smart phone or bluetooth to use them.

 

[Jerry Hall]

Shop used AC equipment. I found an old 134 machine that has the built-in vacuum pump, on board gauges, and will actually measure and add freon from a 30 lb. tank. I paid $400 for it used and then another $200 for a complete service on it.

 

[Lefty71]

Jerry, somebody probably paid $3k plus for that once upon a time.

 

[HawkRod]

First of all, thank you all so far for the great information. Of course, as we learn, we have more questions.

Those will do just fine .Buy yourself a GOOD can tapper or invest in a bottle of R-134.
Then a scale to weigh the bottle if your systems do not have a sight glass.
Robinair has been around for a long time.So the pump should last you a life time.

So I guess this brings up a (newbie) question: I thought A/C systems were typically filled to a set pressure rather than a weight of refrigerant? Or is it both?

Also, I assume when you say "good can tapper" that means the connector and pin that will puncture the R134a (or other) bottles?

EPA Regulatory Requirements for MVAC System Servicing | US EPA

Thanks for these - I want to be as 'correct' as I can be. But it looks like "...these requirements impact service technicians, shop owners, and some refrigerant retailers". I am simply a shade tree mechanic, so not applicable? For example, if this applied to anyone working on their A/C, how could anyone buy a can or R134a from the auto parts store? Yet, people do it all the time. Also, all refrigerant needs to be recycled by special machinery, and that adds additional costs for filters or scrubbers that will do this. So again, this sounds like rules for the professional?

Forget cheap universal gauge sets. Get one from Robinaire, Ritchie or other major brand if you want plain ones. I personally would recommend you get a good set from the start; like this Testo 550;

Testo 550s Basic Hose Kit - Smart Digital Manifold with Wired Temperature Probes and set of 3 Premium Ball Valve Hoses

At first this will look daunting, but understand that they do all the thinking for you...no need for you try and interpret the data....running evap and condenser temps are interpreted for you and displayed right in front of you as you work. Same kit for 60 different refrigerants. BTW, you wont need your smart phone or bluetooth to use them.

These look really nice. I guess these can help a newbie like me better understand what I need to do? But wow, then with these at $450 and a pump and other stuff I am likely looking at at least $800. That starts getting really painful (although I realize that bringing the cars in for A/C service will be painful too).

Shop used AC equipment. I found an old 134 machine that has the built-in vacuum pump, on board gauges, and will actually measure and add freon from a 30 lb. tank. I paid $400 for it used and then another $200 for a complete service on it.

View attachment 1499293

Jerry, I think you are on to something here. As I said above, paying $800 and above starts getting cost prohibitive.

 

[Paul_B]

I’ve used a gauge set and vacuum pump similiar to what you show hawkrod. My gauge set came from harbor freight and the vacuum pump was from Amazon so likely cheaper in every way but it’s worked for me.

I’ve done just a few cars and they have all had no refrigerant in them. After repairs, I’ve pulled a vacuum for 30 minutes and verified it holds with no leaks. As a note I always replace the low and high pressure fill valves and low pressure switch as these have been common issues for me while the system is empty.

I fill using cans of refrigerant to the specified system weight in ounces if possible. I have lucked out and found cans that add to the required system ounce weight requirement sometimes or weighed with a cheap scale on amazon.

I have found pressures are difficult to tell for someone with my skills and tools to tell if properly charged. I use my gauges to ensure the high side and low side pressures seem in the ballpark to tell me everything is functional. Temperatures of the air, engine, and cabin can change the pressures in the system some.

I’m just a shade tree mechanic too so I’m sure my AC work is not top notch.

 

[HawkRod]

I’ve used a gauge set and vacuum pump similiar to what you show hawkrod. My gauge set came from harbor freight and the vacuum pump was from Amazon so likely cheaper in every way but it’s worked for me.

I’ve done just a few cars and they have all had no refrigerant in them. After repairs, I’ve pulled a vacuum for 30 minutes and verified it holds with no leaks. As a note I always replace the low and high pressure fill valves and low pressure switch as these have been common issues for me while the system is empty.

I fill using cans of refrigerant to the specified system weight in ounces if possible. I have lucked out and found cans that add to the required system ounce weight requirement sometimes or weighed with a cheap scale on amazon.

I have found pressures are difficult to tell for someone with my skills and tools to tell if properly charged. I use my gauges to ensure the high side and low side pressures seem in the ballpark to tell me everything is functional. Temperatures of the air, engine, and cabin can change the pressures in the system some.

I’m just a shade tree mechanic too so I’m sure my AC work is not top notch.

This is a great add - thanks Paul.

Yeah, I'm not trying to become the best outfitted A/C guy around, but like you, simply to be able to service my systems and make them work reliably.

Do you mind expanding on your statement:

I always replace the low and high pressure fill valves and low pressure switch as these have been common issues for me while the system is empty

Thanks,

Hawk

 

[Virg464]

It's been years since I did any A/C work for a living. But, if your going to be opening up the system to do repairs, you want an Recovery/Charge System like the one mentioned earlier. You need to capture the freon that's in the system before you crack it open. Also, you'll want tp read up on PAG oil (I think that's the name), you need to add that to the system when you recharge it with freon. The PAG oil is a compressor lubricant, so you don't end up with bits of metal running through the system. I might be out of date on things, but you really have to be careful with these systems.

 

[Paul_B]

The low pressure switch or AC cycling switch on some systems turns the compressor on/off. They can wear just by the constant cycling on/off especially if the compressor had issues I’ve replaced a couple of bad ones and they are cheap and easy to do when empty.

The fill valves are sometimes like replacing the core in a tire valve stem. Alternatively , sometimes you can unscrew the whole “valve stem” or port and it’s like a cap that has the valve. There is just a little spring loaded seal in the valve that holds the refrigerant in. The seal can fail and all your hard work slowly leaks out the port after you disconnect your gauges.

I knew someone that had an AC system that was completely empty and partially torn apart from a previous repair attempt. They went through everything to recharge. The gauges were hooked up the entire time they pulled the vacuum which showed no leak. This didn’t show they had a leaky high pressure service port valve. When they disconnected the gauge from the high pressure port it sounded like a leaking tire.

To me it’s cheap insurance especially when preventive repairs like the service port valves and low pressure switch can cost less than the cost of the refrigerant in some cases. I generally opt to replace anything in older systems that are common failure items as I hate doing anything twice.

 

[bandit67]

What Lefty said about not getting a cheap set of gauges. I have an old set of R 12 gauges that was my main set. When the R 134 stuff hit I got a new[cheap] set for that use. They are snap on rather than screw on like R 12 systems. The cheap set NEVER have/did attach and ran true. I finally paid about $40 bucks for an R 134 to R 12 adapter and that is what I use all the time if R134 is needed. Im sure that gauge setup is fine....it's just those snap on fittings are useless.
Gauges and vacuum pump are a must. Ive got a recovery unit and don't use it any more....not in years. That robin air pump is similar to my model and it has lasted me for years. I don't like using the small cans anymore and much prefer the 30 pound tank. Stock up on whatever, new laws are in place to shut down production of all refrigerants .

 

[MoparRobTX]

I've been using harbor freight gauges and vac pump for 10 years. Done probably 20 services on various family and friend vehicles. I think both were less than $150 together.

 

[HawkRod]

The low pressure switch or AC cycling switch on some systems turns the compressor on/off. They can wear just by the constant cycling on/off especially if the compressor had issues I’ve replaced a couple of bad ones and they are cheap and easy to do when empty.

The fill valves are sometimes like replacing the core in a tire valve stem. Alternatively , sometimes you can unscrew the whole “valve stem” or port and it’s like a cap that has the valve. There is just a little spring loaded seal in the valve that holds the refrigerant in. The seal can fail and all your hard work slowly leaks out the port after you disconnect your gauges.

I knew someone that had an AC system that was completely empty and partially torn apart from a previous repair attempt. They went through everything to recharge. The gauges were hooked up the entire time they pulled the vacuum which showed no leak. This didn’t show they had a leaky high pressure service port valve. When they disconnected the gauge from the high pressure port it sounded like a leaking tire.

To me it’s cheap insurance especially when preventive repairs like the service port valves and low pressure switch can cost less than the cost of the refrigerant in some cases. I generally opt to replace anything in older systems that are common failure items as I hate doing anything twice.

Thank you - this makes great sense.

 

[Darter6]

Hawk, I should have been clearer on "Can Tapper"
For R-134 1 lbs cans they make a screw on tapper with a valve to pierce the can that if you don't use all you can close the valve and it will seal. The also have the plastic tapper that pierce the side of the can. Those I don't recommend.They work but not my favorite. The old R-12 and R-134 did not have a threaded top, the tapper gripped the rim of the can.I believe those cans are no longer made but are still around at swap meets.

 

[BMosely]

Harbour Freight for the vacuum pump will save some money. Decent gauges will get you down the road. A lesson on my side, go ahead and throw some dye in the system when you build it. Easy to do and if issues pop up you can chase it. On the Coronet that was a complete new install, everything sucked down and was good. Months later it leaked and it turns out to be one of the pressed hose connections. I am not sure how those can get done incorrectly but it looks like Predator is bleeding out under the UV light.
Also, on brand new installs, the compressor will not be running to place the Freon. I found that heating the cans up in a bucket of very warm water will create a good pressure differential for the system to take.

 

[Darter6]

I found that heating the cans up in a bucket of very warm water will create a good pressure differential for the system to take.

Yeah, after pumping the system down and using cans, it will help empty the can faster.

 

[Nxcoupe]

1. Never, ever, use refrigerant with a leak stopper or sealant.
2. New regulations are on the horizon where 134 will require a license for purchase and eventually will be discontinued. R1234yf is the latest refrigerant being used.
3. A good set of gauges, Robinaire, etc. Buy once and buy quality.
4. Vacuum pump, what you listed is fine.
5. No, pressures tell you what is happening inside the system, but systems require a minimum fill weight which should be listed on a sticker somewhere around the engine compartment or also in Service Info.

Hope this helps.