DIY not (or the wrong way to re-gas a car’s aircon system)

Doram

A few years back my car (2007 Zafira) needed an aircon gas recharge. Having never done it before (and not being smarter), I went to a Halfords shop. Someone came out to the parking lot with a can of gas connected to a hose with a trigger and gauge. After some trouble he managed to do something, the aircon produced some cold (not freezing) air. I paid and we parted ways.

A couple of years later the aircon needed gas again, and I thought that spraying some gas into a port in the car (as the Halfords guy did) is something I can do myself. So I found a cheap product on the internet (with raving reviews) and gave it a go. This was a mistake. It was impossible to connect the connector to the low-pressure port in the car. As I tried – I pushed the pin in, and the little gas that was in the system escaped. It was a disaster, but eventually I somehow managed to get some gas back in, and the aircon produced some cool air (no way I could get a reading from the gauge, so I had no idea how much gas I put in and what the pressure was, but it worked, sort of) . A year later I tried to repeat, but for the life of me couldn’t do it: gas was escaping, connector wouldn’t connect. Everything felt wrong. I concluded I needed a better gas trigger that I will hopefully be able to connect to the port.

On the way to Halfords to buy a new trigger, I stopped at my local garage to ask for advice. When I saw their re-gassing device (a machine the size of a little fridge, probably costing thousands of pounds) and heard what it does, it was a no brainer – I asked the garage to do it for me.

The machine was connected to both the low- and high-pressure ports of the car for almost an hour. In that time it flushed all the old gas out (85 grams is all that came out), then tested for leaks, then vacuumed the whole system clean, then pumped in new gas and oil to the manufacturer’s instructions (450 grams of gas). The result was an aircon blowing out freezing air like it never did. The cost of this service from the garage was £55.

In contrast, Halfords man-with-a-can service cost about the same (if not more) and took a few minutes in the parking-lot to complete: no flushing, no testing, no cleaning - just a few squirts of gas top up. This is just madness. I am not even sure it’s the same gas (because the real R134A refrigerant is illegal to handle by a non-qualified person).

I love doing things myself if I can (pun unintended), but I wonder how many things I do that I really should be leaving to professionals). Well, that’s one lesson learned.

Cuprajake

yep its also illegal to release it to the atmosphere, it boils at below room temp so you could of badly burnt yourself.

the price you paid is pretty good, as its getting on for £300 for a 13kg bottle, the newer gas is triple the price, and needs another machine, you have to pay to be licensed so anyone who pays can do it lol

Meldrew

I would not go to Halfords if they are just topping up the system. The garage with the proper machine is the way to go. They should actually weigh how much refrigerant is actually removed. This will let them know how much has been lost if any. The system should be checked for leaks then vacuumed and then refilled. As Cuprajake said it is illegal to vent refrigerant out deliberately. I had a big argument with a dealership when they wanted to remove the refrigerant then put that same refrigerant back and top up the losses. I then explained to the person that the refrigerant is made up of different refrigerant elements which change state from a liquid to a gas at different temperatures/ pressures.This is called the glide. So you have to refill the system with new as you would not know which refrigerant and how much of each that has actually been lost. The man concerned would not have it, so Obviously they did not get my custom.

Doram

Meldrew I would not go to Halfords if they are just topping up the system. The garage with the proper machine is the way to go. They should actually weigh how much refrigerant is actually removed. This will let them know how much has been lost if any. The system should be checked for leaks then vacuumed and then refilled. As Cuprajake said it is illegal to vent refrigerant out deliberately. I had a big argument with a dealership when they wanted to remove the refrigerant then put that same refrigerant back and top up the losses. I then explained to the person that the refrigerant is made up of different refrigerant elements which change state from a liquid to a gas at different temperatures/ pressures.This is called the glide. So you have to refill the system with new as you would not know which refrigerant and how much of each that has actually been lost. The man concerned would not have it, so Obviously they did not get my custom.

The proper machine in the garage fully automated the whole process. The mechanic connected the two hoses, pressed the button and went away, leaving the machine to do it’s thing over close to an hour. A computer screen gave loads of information about the process along each stage (pressures, temps, amount of refrigerant out and in etc). It even printed out the main information for me to take when it finished (so I know I only had 85 grams in there, while 450 grams are needed). I wish I had known this before, but sadly I didn’t. The fact that Halfords does a DIY job and charges the same as a garage threw me off. Also the fact that there are thousands of positive reviews on the internet by people who use a can to top up and say it’s great (the absurd is it’s hardly cheaper than what the garage charges). It does do something (it did for me as well), but certainly not what a proper job does. I will of course know better in the future.

Cuprajake

Friend of mine, my best man in fact!!! Don’t know why he didn’t ask me,

Went to Halfords to have bulbs fitted. Paid £27 fitting and they fit his bulbs upside down ffs h7 bulbs only fit one way, they also broke the spring clips, needed 2 new headlights!!

DavecUK

Aircon systems need to be vacuumed out, then properly regassed, sometimes they will even fill with a refrigerant that will show leaks under UV light. If you are having to do it every few years…you have a leak which should be attended to.

Meldrew

I have never worked on Car AC. I was told years ago that you should run the ac in the winter so that the refrigerant which will then lubricate the system and keep the rubber seals from drying up and then leaking.

Meldrew

The machine that they use does simplify the whole process. I used to work on the heat pumps in conveyor dishwashers. We had to suck out the refrigerant using a reclaim unit, then leak test with Nitrogen, on hard leaks we sometimes put a dye into the machine.Then pressure test with Nitrogen then vacuum out the system and finally refill the refrigerant and test. A lot slower than doing the car ac. I had to get all this gear to the dishwasher which was never straightforward. Many a time I had to carry everything which Kept me fit.

Cuprajake

What gets me is it costs so much to get a air con license, to just connect two hoses and press a button.

The new ev jaguar land rover use air con to cool the batterys. Should they see a pressure drop the car won’t start

Doram

Cuprajake What gets me is it costs so much to get a air con license, to just connect two hoses and press a button.

I suppose the licence is for preparing, storing, disposing consumables, maintaining the equipment and dealing with things when they go wrong? Luckily mine was straightforward, but I assume it’s not always that easy. Plus they want to make money, hopefully to put into good things, but realistically - who knows what they do with it?

Meldrew

It’s mainly the safe handling of Refrigerants that it’s all about. The good old Ozone layer. I had to go on a course and pass a test for the R600 refrigerant when it first came out. This one has Butane in the mix. More hazardous work. Obviously you have to be trained to know how the equipment functions and the science of the refrigeration cycle, which helps when fault finding. Not sure what the minimal training will be required for car ac, the principal should be the same other than the equipment that seems a lot simpler to use as it’s all in one unit.