Having a hard time trying to chase down an AC refrigerant leak. Are there any common areas where I should look? The ac will hold for a few days but then goes warm again assuming I’m losing freon somewhere.
Common 200 series A/C leak? (1 Viewer)
- Thread starter ironmountain
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Check that the AC condenser in front of the radiator doesn’t have a tiny leak. It’s low and prone to gravel hits. Also check the 2 connections behind the driver side rear wheel as these aluminum fittings can corrode and leak.
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- Thread starter
- #3
Will check. Thank you!
bloc
SILVER Star
If you have corrosion definitely check the rear lines at the connection just below the floor of the passenger compartment. I’ve seen at least a dozen posts in this section of issues in that area.
- Thread starter
- #5
Any photos of where exactly that is?
bloc
SILVER Star
No, but it's not too hard to find. The AC lines are silver aluminum, one big one small, that run along the bottom of the vehicle then across the top of the rearmost muffler on the exhaust (the resonator), then into the floor of the vehicle. If you are lying under the back looking at the driver's side behind the rear wheel you should see them.
There will also be two larger silver pipes for coolant into the heater core up there. But the large/small combination are the AC lines, and you'll see a lug of aluminum there along each line with a bolt. This is the fitting that allows the lines to disconnect from the core inside the rear AC unit.
Karbon
SILVER Star
I replaced a condenser on a 2013 that was leaking at the weld to the mounting bracket. On my 2009 I have a slow leak which appears to be in the finned section of the condenser from the hits it has taken over the years. I have had the condenser sitting since last fall with no time to address it yet.
While the system is uncharged, I have replaced the Schrader valves in the low port and high port as well since those O-rings get old and leak over time. If it's leaking significantly, when you unscrew the cap you can hear a slight hiss from depressurization.
While the system is uncharged, I have replaced the Schrader valves in the low port and high port as well since those O-rings get old and leak over time. If it's leaking significantly, when you unscrew the cap you can hear a slight hiss from depressurization.
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- #8
first pic is when the Ac is off and pressure holding.
When I turn the ac on I hear the condenser click on and the gauge drops to 0.
And when the ac is turned off the gauge jumps back up to full
All while the ac still doesn’t blow cold.
Not sure if this means anything but if so chime in. Thanks!
When I turn the ac on I hear the condenser click on and the gauge drops to 0.
And when the ac is turned off the gauge jumps back up to full
All while the ac still doesn’t blow cold.
Not sure if this means anything but if so chime in. Thanks!
That is expected behavior when the system is under-filled.
- Thread starter
- #10
Should a gauge be showing any signs of it being filed while the ac is on? Or does a gauge drop when it’s on
If you will base it on the gauge on the can it should be in the green area once the system is near capacity. That is compressor engaged and low side hose/line should be cold. Look for wet spots in your a/c lines and front of condenser you could also have dye added to the system.
When the system is running correctly the low side should drop no lower than ~20-30psi before the compressor cycles off. The specific low side/high side target pressures vary by vehicle, ambient temperature and type of refrigerant used.
When the ac has been stopped for a while the low and high side will equalize to the refrigerant vapor pressure at the local temperature, assuming some liquid refrigerant remains in the system. That’s why it is more accurate to refill ac systems by weight vs v pressure.
I have converted some older vehicles that started life on R12 (and then underperformed on R134a) over to a butane/propane blend which is more efficient and generates lower head pressures. Less leak prone as well…though the risk associated with a leak is slightly different than with R134a…
When the ac has been stopped for a while the low and high side will equalize to the refrigerant vapor pressure at the local temperature, assuming some liquid refrigerant remains in the system. That’s why it is more accurate to refill ac systems by weight vs v pressure.
I have converted some older vehicles that started life on R12 (and then underperformed on R134a) over to a butane/propane blend which is more efficient and generates lower head pressures. Less leak prone as well…though the risk associated with a leak is slightly different than with R134a…
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- Thread starter
- #13
Are you located in SoCal by any chance and work on these rigs? I’m desperate to get this fixed before our summer road trips
Unfortunately I am not, I’m up in NorCal. And strictly a keen amateur in these matters. Recommend finding a shop or individual who owns a high/low gauge set, vacuum pump and leak sniffer to track down the leak.
- Thread starter
- #15
Thank you
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- #16
Update:
Went and had a shop replace some ac lines in the rear which they claimed fixed the leak. Got the truck back and found a puddle in the street under the drivers side in the middle and found this….
bloc
SILVER Star
Puddle of what? Water? That’s where the air conditioning condensate (water) drain for the dash climate control is.
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- #18
To the touch it’s yellow liquid.
That is after the vehicle was sitting all week.
I’ve ran the ac before and never had it drip on that side before
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- #19
Also, the liquid didn’t evaporate like water does.
bloc
SILVER Star
Then yes it’s probably AC system oil and that is likely a leak source. If you have a cool box in your console those lines run up into it. If not it’s possible that’s a joint before the lines run back to the rear AC.
The leak at the rear is somewhat common in vehicles with corrosion. From memory this would be one of the first I’ve seen posted with a leak in this specific spot.
But yes the condensate drain is in that area, sorry for the confusion.
