Another air con problem

[Peter Palmer]

On our other van the aircon hasn't worked at all this year. This is what I can deduce up to now, last year it worked fine so there must have been refrigerant in it. When it didn't work this year I had a quick look at it and ended up pressing the schrader valve down, nothing came out so obviously it has had a leak in the meantime. The compressor isn't engaging either but I assume that's because there's no air in the system.

So I dropped it off at our local garage to have a look, he hooked it up to a machine and some bottles and after an hour or so he said yep its leaking somewhere that will be £50. Now I'm no expert but I thought I might have got a bit more detailed explanation than that with £10K of machinery knocking about. I mentioned putting a UV dye in but he said it goes in with the refrigerant and he's not allowed to put that in because its leaking.

Now am I being a bit thick here or am I missing something? before you can put the leak tracer into the system you have to stop the leak, whats the point in putting the dye in if you fix the leak first then?

All he could tell me was it failed the vacuum test and failed the pressure test, dropping about 50PSI and he thought it could be the condenser as it sits at the front of the vehicle and is prone to damage.

[cancunia]

Seems a bit daft that they can only inject the dye with refrigerant. I've read elsewhere that nitrogen is used with the dye when testing for leaks. Maybe worth checking around locally for some specialists and see what they say.

[Peter Palmer]

I think its because you have to have the system running to expose any leaks and it won't run with just nitrogen in it. Apparently the gas kills all the kittens or something so he might get fined if he puts it in the system knowing it will leak out.

So as the old saying goes, if you want something doing then do it yourself. You can buy all the gear you need on Amazon and Ebay, vac pump and gauge set is only £150 and the gas is quite cheap as well. Its a pity I spent £50 on it, would rather it had gone to fixing it myself now.

[cancunia]

AFAIK, the problem with the vacuum test is it's not 100% effective as the schrader valves are not tested. But if you only want a vacuum test, book a test & re-gas with ATS via Groupon. According to the blurb, they will refund your money if the test fails.

[Peter Palmer]

Who needs aircon experts.





Oredered one off ebay, £56, coming in 2 or 3 days so junst need to re-fit it and get it tested/ filled.


PS do you think the o-rings on the 2 pipes need replacing where they connnect to the condenser?

[Tomcat3]

That is a neat test and saved money into the bargain. I would change the o rings to be on the safe side they aint going to be expensive.

[Lighty]

The condenser tends to fail where the fan sucks air & grit through . If you had to make an educated guess, it will 90% likely be the condenser that leaks.
It is illegal to put gas into a system these days if you know it leaks. £10000 fine apparently,
Nitrogen is used to fill the system instead as it contains no moisture. 
You pressurise it up & look for bubbles with soapy water etc.
Filling it with compressed air is the same, but you are putting moisture in the system which is very bad, as ice particles will form & wreck the compressor.
The gas  R134a is very expensive currently , it has dropped lately to about £260 for 13kg, 18 months ago it was £70.
R1234yf gas that is in newer cars, manufactured after 2015 is about £400 for 5kg.
Obviously you wouldn’t want to throw this gas (either type ) into a potentially leaking system.
The pressure switch in the system will cut off the compressor once the gas pressure drops below a predetermined amount.
The reason for this is that the compressor will suffer oil starvation as the gas carries the lube around, so no gas in the system would equal huge damage.
Most fast fit type outlets offer no repair service, so will only fill it up if there is no apparent leak.

[Peter Palmer]

Took it to ATS this morning for a Groupon top up and he reckons something is still leaking, I didn't change the o-rings at the time but have since found a little packet taped to the side of the box the new one came in, didn't help as the ad for the condenser stated "PLEASE NOTE THIS CONDENSER ISN'T SUPPLIED WITH O-RINGS". I must admit the bottom hose seemed to be in a lot better with the new o-rings on so I can take it back, you get a refund if it fails the vac test apparently so he never validated the voucher, not sure how many times you can take it back until the bloke flips out though.

My next question is obviously I can't keep taking it back so if it still leaks how would I be able to pressurise the whole system up myself. I know you are meant to use nitrogen but I'm happy to do it with compressed air and I've got a little compressor, the two service valves on the system are bigger than a standard car tyre Schrader valve though. I don't mind buying a set of manifold gages but the yello pipe still has a 1/4SAE fitting on the end and I cant find an adaptor to go from pump Schrader valve to 1/4SAE.

PS I know compressed air is bad for aircon systems as opposed to nitrogen but as the system has been empty for a while its obviously full of normal air anyway and certainly will be after fitting the new condenser,

[Lighty]

Not strictly true, as you new condenser has a dryer built into it, so it’s a shame to fill it with wet compressed air.
Why not just get it tested by someone with Nitrogen ?

[Peter Palmer]

Not strictly true, as you new condenser has a dryer built into it, so it’s a shame to fill it with wet compressed air.
Why not just get it tested by someone with Nitrogen ?

The only problem with that is its £50 every time I go, whats the score with buying a bottle of nitrogen from somewhere and getting the appropriate fittings/pipes to test it?