Car aircon, leaks and uv lights

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Car aircon, leaks and uv lights

Post by ..... »

Topped the gas up in the car over a month ago as it just wasn't cooling. Done about 1000 miles since the...... and back to square one again.
However, the stuff I put in had some uv dye additive, which I'm told requires a uv light to trace the leak (s)
Question is, will any old uv light work (cheapo amazon thingy) or does it need a proper jobbie?
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Mussels
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Re: Car aircon, leaks and uv lights

Post by Mussels »

Cheapy ones will be the right colour but maybe not as bright, buy cheap and do it at night.
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Re: Car aircon, leaks and uv lights

Post by KungFooBob »

On an semi-related note.

How did you top the gas up the first time?

If you did it via a trader they should have drained the system, then pressurised it and checked for leaks, before refilling it with the right gas.

If you topped it up yourself without wondering where all the old gas went, then maybe you need to have a think about that :)

I had mine done on a JCW Mini, it failed the test. They sent me away with a bottle of STP stop leak stuff. I'd followed the instructions and the next weekend went for a free re-test, it passed and they filled it with gas and it worked until I traded it a year later.
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Re: Car aircon, leaks and uv lights

Post by Mr. Dazzle »

KungFooBob wrote: Sun Aug 10, 2025 8:11 pm On an semi-related note.

How did you top the gas up the first time?

If you did it via a trader they should have drained the system, then pressurised it and checked for leaks, before refilling it with the right gas.

If you topped it up yourself without wondering where all the old gas went, then maybe you need to have a think about that :)

I had mine done on a JCW Mini, it failed the test. They sent me away with a bottle of STP stop leak stuff. I'd followed the instructions and the next weekend went for a free re-test, it passed and they filled it with gas and it worked until I traded it a year later.
That ^

Gas doesn't just magically teleport away..... ;)

"Just needs a regas". Yeah. Because it's got leak :obscene-birdiedoublered:
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Re: Car aircon, leaks and uv lights

Post by ..... »

KungFooBob wrote: Sun Aug 10, 2025 8:11 pm On an semi-related note.

How did you top the gas up the first time?

If you did it via a trader they should have drained the system, then pressurised it and checked for leaks, before refilling it with the right gas.

If you topped it up yourself without wondering where all the old gas went, then maybe you need to have a think about that :)

I had mine done on a JCW Mini, it failed the test. They sent me away with a bottle of STP stop leak stuff. I'd followed the instructions and the next weekend went for a free re-test, it passed and they filled it with gas and it worked until I traded it a year later.
And this is why I'm asking the question, because the dye will highlight where the leak is. If the condenser is fubar, I won't bother shoving more gas in there, if a seal is weeping, then a proprietary bodge or proper repair will be done prior to refilling
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Re: Car aircon, leaks and uv lights

Post by ZRX61 »

..... wrote: Sun Aug 10, 2025 10:24 pm And this is why I'm asking the question, because the dye will highlight where the leak is. If the condenser is fubar, I won't bother shoving more gas in there, if a seal is weeping, then a proprietary bodge or proper repair will be done prior to refilling
Old systems use flare fittings, modern stuff uses O rings.. so if it's O rings then fixing the leak is pennies. Not sure what the law is where you are, but here it's illegal to vent the gas to the atmosphere... but if there's bugger all in it you're good to go. You can pressurize the system with nitrogen while looking for leeks.

.. then there's the oil in the system
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Re: Car aircon, leaks and uv lights

Post by ..... »

Internet says O rings
20250816_185124.jpg
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Re: Car aircon, leaks and uv lights

Post by edulord »

Honestly, cheap UV lights can sometimes show the dye, but they’re usually not bright enough to spot small leaks. If it’s a tiny drip, you’ll probably need a proper one from a garage or a decent kit. For a quick check, the Amazon ones might give you a clue, but don’t expect it to be super precise.
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Re: Car aircon, leaks and uv lights

Post by mangocrazy »

ZRX61 wrote: Sat Aug 16, 2025 2:44 pm You can pressurize the system with nitrogen while looking for leeks.
You sure about that boyo?
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