AC regas, can it be tested beforehand?
AC regas, can it be tested beforehand?
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Discussion

Mrinsignia

Original Poster:

176 posts

101 months

Monday 22nd May 2023
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I bought a new (to me) car and today realised the air con isn't very effective. I am booked to take the car into Kwik fit tomorrow for a regas, but will they test it to make sure the system work before doing a regas, or will I only find out after they have(possibly unsuccessfully) done it?

Joelonghair

280 posts

102 months

Monday 22nd May 2023
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Not sure about Quick Fit, but Halfords offer a free AC test.

I took my Audi TT mk1 the other day after the AC stopped blowing cold. They checked the gas and it was full so nothing to pay - to them at least!

Any pointers on where to take the car to get the AC further diagnosed received with thanks.

littleredrooster

6,404 posts

226 months

Monday 22nd May 2023
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They are obliged to test the system for leaks before re-gassing it. If it fails the test, it needs to be fixed.

Chromegrill

1,140 posts

116 months

Monday 22nd May 2023
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Took my car to a quick fitting chain of garages once as my aircon wasn't working. They said it was a bit on the low side so topped it up, and still it wasn't working. So they explained they would have to drain it completely of coolant to help me get the leak properly fixed. And so they did.

Took it to an aircon repair specialist who immediately spotted the compressor pump fuse had gone. Replaced that, topped up completely with gas and two years' later it's still as cool as ice. Shame I had to pay for an entire new lot of gas though!

SimonTheSailor

13,017 posts

258 months

Monday 22nd May 2023
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Took a car to Halfords recently and they tested the pressure - it was down to about 16psi (about half what it should be apparently).
They topped up the gas and that was that.....

deckster

9,631 posts

285 months

Monday 22nd May 2023
quotequote all
Get an air-con specialist in. Kwik fit and the like are useless, they kept telling me my 996 was fine as their machine said it was, but it was still empty a couple of months later.

Whereas the guy I found using google was brilliant, came to my house and waved a magic wand (I presume a gas detector of some sort) all over the car, then pinpointed exactly where the leak was and told me what needed replacing. Slightly more expensive for the regas than kwik fit but worth the extra for somebody who actually knew what he was doing.

Chromegrill

1,140 posts

116 months

Monday 22nd May 2023
quotequote all
Joelonghair said:
Not sure about Quick Fit, but Halfords offer a free AC test.

I took my Audi TT mk1 the other day after the AC stopped blowing cold. They checked the gas and it was full so nothing to pay - to them at least!

Any pointers on where to take the car to get the AC further diagnosed received with thanks.
I have taken two cars with non-working aircon to Halfords for a regas check to be told in both cases it was full so nothing to top up. Despite it not working (and in the case of one, there was a leak, in the other, it was low when checked properly).

Goodness knows how Halfords test for aircon gas!

Joelonghair

280 posts

102 months

Monday 22nd May 2023
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Chromegrill said:
I have taken two cars with non-working aircon to Halfords for a regas check to be told in both cases it was full so nothing to top up. Despite it not working (and in the case of one, there was a leak, in the other, it was low when checked properly).

Goodness knows how Halfords test for aircon gas!
They used a pressure tester (similar to a bike pump) that connects to the fill point. Would be happy if it was just the gas, so will look for an AC specialist near me (Manchester).

fooman

1,274 posts

94 months

Tuesday 23rd May 2023
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I've used Kwik Fit several times to regas cars I've bought. Although they don't do diagnosis they usually say if it's not blowing cold after regas no charge. Only once had to gas a car again but did it myself with a kit from Halfords as I couldn't get a booking soon enough. That's been going strong for a couple of summers now. The kit is expensive but can pump up the AC a couple of times. I'd probably only use this kit on a car that was working recently.

tivver500

376 posts

300 months

Tuesday 23rd May 2023
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If your car is using one of the 'old' freon gases (i.e. R12) then you can get away with checking the compressor suction pressure and topping up accordingly.

However the latest gas (R1234), which is more environmentaly friendly, is tested by actually weighing the amount of gas in the system. My local Ford dealer has a machine that sucks all the gas out, weighs it, then tops up as necessary to the designed weight for that vehicle.

R1234 runs at a higher pressure than R12 so is much more susceptible to leaking!!

A quick check is to rune the air-con for several minutes, at MAX setting, then monitor the temperature in the air vent. A good system should get down to about 12deg (with ambient temperature of around 20deg).

Or, in true PH tradition, just take the roof off

Geoffcapes

1,308 posts

194 months

Tuesday 23rd May 2023
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Quikst ruined the aircon on my old Alfa by somehow breaking something on the point the system is regassed.

Denied it was their fault and refused to fix it or pay me a penny.

I wouldn't trust them to put air in my tyres.

TO73074E

502 posts

57 months

Tuesday 23rd May 2023
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Definitely get an AC specialist to check the system. I used a mobile specialist who came out to me when I had an issue, turned out to be a leaking condenser so it was replaced and re-gassed.

Before I spoke to the AC specialist I took mine to KF and asked if they could do a check on the system to give me an idea of what was wrong. The lads exact words after doing his 'checks' were "It's got a leak but I don't know where."
Yeah cheers Columbo.

MajorMantra

1,704 posts

142 months

Tuesday 23rd May 2023
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I've been through the Kwikfit dance. As I understand it their machines do a vacuum test, which won't pick up small leaks in some cases, eg mine where all the gas leaked out in a couple of days.

This guy sorted me out: https://www.gocool.co.uk/ I needed a section of pipe splicing in as corrosion had caused a pinhole. He's South West-based if that's any good to you...

blue_haddock

5,048 posts

97 months

Tuesday 23rd May 2023
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All AC machines will do a vacuum leak test before recharging the vehicle.

However this is not a definitive leak detection method as the vacuum can pull small holes or perished seals shut so it passes but there is still a leak.

This is where a nitrogen pressure test comes in, by using positive pressure it will blow open any holes and helps locate the leak.

If it passes the nitrogen test in theory there is no leak so of it's still not working it would be something like.tbe pressure switch or faulty compressor.

Some Kwik fit sites can do nitrogen pressure testing but not all of them.

blue_haddock

5,048 posts

97 months

Tuesday 23rd May 2023
quotequote all
deckster said:
Get an air-con specialist in. Kwik fit and the like are useless, they kept telling me my 996 was fine as their machine said it was, but it was still empty a couple of months later.

Whereas the guy I found using google was brilliant, came to my house and waved a magic wand (I presume a gas detector of some sort) all over the car, then pinpointed exactly where the leak was and told me what needed replacing. Slightly more expensive for the regas than kwik fit but worth the extra for somebody who actually knew what he was doing.
That would be a refrigerant sniffer which detects small leaks, they only work though of there is still some gas in the system. If it's been empty for ages it can't find anything as there is nothing to find.

Martin_Hx

4,029 posts

228 months

Tuesday 23rd May 2023
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Very apt name... the other week we had our Insignia air con regassed via ATS (groupon voucher) @ £42 i think it was.

I thought it was worth a punt, if it leaks out, we are going to try some AC leak stuff

blue_haddock

5,048 posts

97 months

Tuesday 23rd May 2023
quotequote all
Martin_Hx said:
Very apt name... the other week we had our Insignia air con regassed via ATS (groupon voucher) @ £42 i think it was.

I thought it was worth a punt, if it leaks out, we are going to try some AC leak stuff
I wouldnt bother, unless the hole is microscopic the sealants dont work.

I'm actually an automotive ac specialist and we have tried pretty much all of the ones on the market, they just dont work.

Here is the website for one of the most popuar products on the market and they say it only works on holes of up to 0.3mm.

https://shop.errecom.com/en/product/extreme/

Martin_Hx

4,029 posts

228 months

Tuesday 23rd May 2023
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Thanks for the heads up Haddock

Pitre

6,419 posts

264 months

Tuesday 23rd May 2023
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I have to say I got excellent service from Halfords last time I wanted a pressure check. Excellent.

Mrinsignia

Original Poster:

176 posts

101 months

Tuesday 23rd May 2023
quotequote all
MajorMantra said:
I've been through the Kwikfit dance. As I understand it their machines do a vacuum test, which won't pick up small leaks in some cases, eg mine where all the gas leaked out in a couple of days.

This guy sorted me out: https://www.gocool.co.uk/ I needed a section of pipe splicing in as corrosion had caused a pinhole. He's South West-based if that's any good to you...
Great I am SW based so will get in touch.