tracking down an AC leak on a Transit Connect, and that 'leak stop' stuff

Jayne

Jayne

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The AC in my new (used) car stopped working. Compressor just cycled on and off.

It had been serviced as part of the pre-purchase work at the dealership, so I called them and asked the service department what they had done. Advisor said "we found no leaks, it was just out of refrigerant so we just filled it back up". Sigh. Nice job of kicking the can down the road and making it my problem two months later. Here I thought dealerships were getting better. My mistake.

Anyway, got some regular 134a and dye in the system and it's running, now I just need to borrow a buddy's UV light setup and we can see what's leaking.

My theory is that they did find the leak but it was something expensive so they just cheated. But perhaps it's just an o-ring they missed... or perhaps I'll win the lottery.

If it is a leaking compressor, if I try the 'leak stop' stuff what else is likely to screw up if it doesn't 'fix' it? Can it actually fix it or does it just gum crap up and cost more 2 months later?
 
Them saying "it had no leaks, just out of refrigerant ". MEANS it HAS A LEAK !
You should have berated him til he was fetal position...

On to your question, like said: don't use the leak stop. If it's the compressor seal get a new compressor. It will be worth it in the long run. Buy once, cry once.
 
Mirac said:
Them saying "it had no leaks, just out of refrigerant ". MEANS it HAS A LEAK !
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Wha? The hell you say. I figured it was like a bad teenager and just snuck out and forgot to close the window behind it. :)

The service chick said it with such conviction though, she probably believes it.
 
AC stop leak is the poor man's road to an even more expensive fix later.

Go with your plan to find the leak and work on fixing that. And yes, the schrader valve is a prime suspect. If it's that, don't forget to put a cap over it when you fix it. Keeping dirt out of that valve will keep it from being a problem later.
 
Just got back with a UV light after driving an hour with the AC on, looked around, and..... I can't find anything. I see what the dye looks like on the valve of the can, it's a very bright green under the UV but so far I can't find it anywhere inside the engine bay. High pressure side looks ok, getting at the low pressure side involves removing the wheel well liner (yea, convenient) so I'll have to do that tomorrow when I've got more time. Tried to trace the lines around the front best as I could, but it may require removing plastic around the nose to really see everything.

Had I been thinking I would have weighed the dye can before and after to see if any actually went into the system. It's on the can valve, but that doesn't prove anything.
 
Jayne said:
Just got back with a UV light after driving an hour with the AC on, looked around, and..... I can't find anything. I see what the dye looks like on the valve of the can, it's a very bright green under the UV but so far I can't find it anywhere inside the engine bay. High pressure side looks ok, getting at the low pressure side involves removing the wheel well liner (yea, convenient) so I'll have to do that tomorrow when I've got more time. Tried to trace the lines around the front best as I could, but it may require removing plastic around the nose to really see everything.

Had I been thinking I would have weighed the dye can before and after to see if any actually went into the system. It's on the can valve, but that doesn't prove anything.
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What kind of vehicle.
 
Jayne said:
Just got back with a UV light after driving an hour with the AC on, looked around, and..... I can't find anything. I see what the dye looks like on the valve of the can, it's a very bright green under the UV but so far I can't find it anywhere inside the engine bay. High pressure side looks ok, getting at the low pressure side involves removing the wheel well liner (yea, convenient) so I'll have to do that tomorrow when I've got more time. Tried to trace the lines around the front best as I could, but it may require removing plastic around the nose to really see everything.

Had I been thinking I would have weighed the dye can before and after to see if any actually went into the system. It's on the can valve, but that doesn't prove anything.
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What are you working on?

And dont forget the evap side in the dash for leaks.
 
Mike Overlay said:
And dont forget the evap side in the dash for leaks.
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Nothing on the contraption behind the glove box, but I can't see it on the firewall side. There are a lot of panels and things in the way that will have to be removed, or I need a mirror on a stick.
 
Look around the compressor clutch seal area real well on that . That compressor tends to leak in that area.
 
Find your low port with this port finder. http://acprocold.com/ask-the-pro/port-locator/
Try looking for leaks later tonight after sunset, be easier to see the glow.
The car can be off and sitting a while.

Take a white paper towel and run it along the fittings and hose couplings, easy to see the dye.

Do you have a set of R134a gauges, this tells you what is going on with the system. $40 tool
and a dial thermometer is needed. Put thermometer in center vent. Record temperatures.

You can turn it on max a/c cold setting windows down high blower,
write down how long compressor clutch is engaged and when it disengages, also outside temperature.
This will give you an indication of what is going on with the system if you don't have gauges.
 
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When it comes to a car, anything that is "stop leak" "miracle fix in a can" is bad news.. Period.

Stop leaks for headgaskets can plug up oil gallerys....new motor is need then

Stop leak AC can/will plugs up orifices of the system, valves, even pressure sesnors
 
Amazon delivered a 52 LED UV light sometime last night, so now I've got a super bright light ($9 extravagance). In the dark garage this morning, I could not find any dye anywhere except on the can and on the hose connections. Clearly there is dye in the system because the dye does not use the hose assembly to get in, it's got it's own injector on the can. That means that the dye must have at least touched some part of the system for it to contaminate the hose when I was topping off the 134a.

IMG_2605.jpg IMG_2606.jpg
 
Initially R134a is heavier then air, slowly move the probe under the hoses and connections. I had a small leak at the crimp on the high line before a quick connector. Also check that the high and low cutoff switches are tight.
There is a tool to tighten the Schrader valve, don't remove the valve if system is pressurized. :)
 
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Jayne said:
So maybe I'm expecting too much too fast here? It took 2 months for it to leak down, maybe 2 days isn't enough to leak enough dye to be obvious?
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This would have been great information in the initial post. Yeah I'd say you wont see the dye right away. The sniffer should pick up a leak. To the sniffer that's a big leak.
I would have the vehicle in a garage. The slightest breeze will dissipate the freon and the sniffer might not detect it or make you think its picking it up in another location.
 
Jayne said:
So maybe I'm expecting too much too fast here? It took 2 months for it to leak down, maybe 2 days isn't enough to leak enough dye to be obvious?
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Do you know how much leaked out in 2 months?
The clutch seal maybe leaking when in use. Take a couple pictures of the ac clutch
 
Mike Overlay said:
Do you know how much leaked out in 2 months?
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It took 1/2 of a can (6 oz) to get it to enough PSI for the compressor to stay running. I've put that rest of that can in after I put the dye in and that got it to 35 psi on the low side.

The clutch seal maybe leaking when in use. Take a couple pictures of the ac clutch
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Dude, I shoot a glock. You say to get a picture of the ac clutch and you're going to get this (which is all I could do, it's jammed way down in there):

IMG_2607.jpg

I can't make out any seal surfaces or anything from the angle I can see the pump at.
 
LeeMajors said:
The sniffer should pick up a leak. To the sniffer that's a big leak.
I would have the vehicle in a garage. The slightest breeze will dissipate the freon and the sniffer might not detect it or make you think its picking it up in another location.
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I ran the sniffer around the pump, the high and low ports, along as much of the piping as I could see, and inside the dash. The only time it triggered was when I set it down on the passenger's seat to remove the glove box. I passed it around the seat, door seal, etc trying to figure out WTF it was detecting and it triggered on the headliner. No idea. Inside the dash was nothing, and in/around the compressor and lines with the engine/AC on also was nothing.
 
It may simply be a matter of patience, then. It could be the leak only occurs under certain circumstances, maybe related to temperature conditions, vibrations, etc.

Don't forget to check the entire condenser area, both sides. Engine & A/C running, as well as with the engine and A/C off. Check in the morning before and after starting the vehicle, and check right after a trip when the engine compartment is at normal operating temperature. Check of cold days and hot days.
 
Any idea how long the vehicle was sitting around? My aunt gave me her 2003 Saturn Ion, 33K on it, she drove it once a week,
it was low on refrigerant, I topped it off with the stuff in a can at autozone before I drove it from NJ to Raleigh. Has not leaked since.
 
Jayne said:
Someone else suggested that. Both caps were on from the start of this, sniffer picked up nothing at either valve.
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Check it with caps off and system running on max, you may see bubbles at the valve.
 
You have dye in it just drive it for a week and check again. It doesn't sound like a huge leak. Some sniffers need to be calibrated before use, if you are not familiar with it google fu the owners manual for instructions.
 
Not only does that look like a smoking gun, but it also looks like a cheap and quick fix.

Congratulations!

What lead up to that discovery?
 
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