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Discussion Starter #1
So last year I thought my A/C wasn't blowing as cold as before, but as it was a somewhat mild summer, I didn't use the A/C much. A couple of months ago I thought I heard a weird hiss sound from somewhere in the cabin. Today when driving with the defrost on, noticeable hissing from the dash area. Doing a bit of testing, the hiss only occurs when the A/C or defrost is on, so I assume the refrigerant is low.

My plan is to get a bottle of recharge stuff from the parts store (that has dye and oil in it) and recharge. Before that, any obvious failure/leak points I should look for? I did a quick inspection with the car off tracing the A/C lines from the compressor to the condenser and most of the way to the firewall and didn't see any obvious oily residue to suggest a leak. Anywhere else I should look? I'll also plan to do the checks here too.

The car is a 2013 with 95k miles, so I wouldn't be surprised if an o-ring, seal, or hose is leaking slowly.
 

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If you were leaking enough refrigerant to hear a hiss every time you used the AC, it would be empty already.

The hissing is normally coming from the expansion valve as gas passes through the orifice and pressures normalize, or attempt to normalize.

While you may have a leak, and may be low on refrigerant, the noise you hear is highly unlikely to be gas escaping into the atmosphere.
 

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Discussion Starter #4
Thanks. I never suspected the hiss was refrigerant escaping to atmosphere (sorry if I was unclear) but from the pressures not being able to normalize as crjackson wrote.

I checked the fuse, relay, and clutch for proper operation before charging. I added most of a 12oz can of R134a that contains dye (neon green and UV glow) and stop leak (seems like all the refrigerant brands have some amount of stop leak in them). That got the low side pressure to plateau out at 20 psi with the compressor running, which seems reasonable given it's chilly today (55 F). The A/C was blowing quite cold and I didn't want to overcharge, so I stopped.

I traced the refrigerant lines and didn't see any evidence of leaks from them or the compressor. There is one suspicious greasy looking area on the lower part of the condenser where one of the tubes goes into the manifold. There are a lot of fins missing as well (likely from road debris hits). So, we'll see how long the A/C keeps working and whether a new condenser is in my future.

I'll also add a UV blacklight to the shopping list.
 

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Discussion Starter #5 (Edited)
Confirmed that the condenser has a leak. The bottom tube is bent and leaking. Since it's hot out now, I'm noticing how wimpy the A/C is even after recharging.

My plan is to replace the condenser (ordered a new Ford one from RockAuto for $150) and then have a shop pump it down and recharge. Has anyone replaced the condenser before? A YouTuve video shows it can be unbolted and slipped up and out without removing the bumper...seems easy enough. What's strange is the dudes in the video drained the radiator too. Any idea why since the systems aren't connected and the condenser sits in front of the radiator? Insurance in case someone punctures it?

Thanks!
 

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Discussion Starter #6
So I tackled the condenser replacement today in the 90 degree heat. Oh joy. With the smaller engine block in the V6, I was able to loosen the upper radiator brackets and use a rope on the upper radiator hose to pull everything back a couple of inches without having to remove any hoses. I did have to move the air filter box out of the way and remove the air intake plenum to create some space.

I then got the old condenser out (and the new one in) from the bottom with the car up on ramps--loads of space behind the bumper cover.

I've attached pics of the trashed condenser--notice the fins are gone for the lower 1/3 of it, which coincidentally sits behind the lower grille. I added a piece of stainless steel mesh across this portion of the new condenser to give some protection from road debris (without restricting airflow). We'll see if that helps.

20200718_160000.jpg 20200711_233058.jpg
 

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That is crazy.
I would expect that your bumper cover must be a complete mess, if road debris chewed away at that aluminum condenser like that. Holy smokes!

What kind of roads are you driving on?
 

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Discussion Starter #8
That is crazy.
I would expect that your bumper cover must be a complete mess, if road debris chewed away at that aluminum condenser like that. Holy smokes!

What kind of roads are you driving on?
It's really crazy. The old fins were falling out and crumbling as I removed the condenser, as if the whole thing was either corroded or the fins weren't brazed (?) on correctly at the factory. The bumper cover looks OK, and the rest of the stuff in the vicinity isn't corroded to hell, so it doesn't seem to be due to road salt either.

However, I might periodically squirt some water in there to rinse the condenser off for good measure.
 
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