A/C issues in southern AZ

[Mesozoic]

The heat is coming and my '00 Mountaineer let us down the other day when my family and I were headed back home from the fair. The A/C stopped functioning entirely - a bit of diagnosis with my friend (who is a professional mechanic) and it appears that all refrigerant was lost, rather suddenly. The system holds pressure without issue, but leaks down when pulling a vacuum. Can't seem to find the cause of this and thought I'd ask on the forum to see if anyone had seen something like this before.

Cheers!

 

[koda2000]

There are many places where refrigerant can leak from...

- Compressor seal (behind the pulley)
- O-rings at all line/hose connections
- The condenser (in front of the radiator)
- The evaporator (inside the cabin)

I suggest you put in some UV dye, pressurize the system and using a black light look for the leak point.

or

A/C shops have electronic "sniffers" to help find leaks.

 

[Mesozoic]

Thanks, but holds pressure just fine (no leaks), yet has issues pulling a vacuum. There was dye in the previous charge, all gone. It's charged back up and working fine at the moment - I guess I'll see what happens this summer!

 

[david4451]

If it won't hold a vacuum 100% you have a leak. It may be ok for a time but will need charging regularly till you find leak. My ST did same, leak was in evaporator pin hole in aluminium very hard to find.

 

[Mesozoic]

Yeah it seems very elusive to pinpoint, but it would make sense for the leak to be at the evaporator because we found nothing in the engine compartment. Is the evaporator a complete pain to access as it is in most vehicles?

 

[koda2000]

yes.

 

[Mesozoic]

LOL, it seems that it's accessible from the engine compartment, though?

It does appear that the entire evap core is accessible and serviceable from the engine compartment. Isn't that amazing?! OMG I have had to replace a few heater cores on other Fords and they have not been engineered for servicing the evap core so nicely. The one in my Bronco for example is a complete pain. Same in the Mustang. Explorer? No problem!

 

[Mesozoic]

Alright, so the AC in the Mounty went down again. This time it was parked at my office and just had nothing when firing it up for the commute home. I dropped it off at my local trusted AC shop. Their diagnosis is that the compressor is seized up internally. There's a likelihood of contamination and they're suggesting replacing the compressor (with a new Motorcraft unit), new accumulator, maybe new hoses, clean out the evaporator and replace the condenser. Thoughts on component upgrades?

I'd like to run a Sanden or Seltec compressor, but not sure if there is a drop-in replacement for the OE unit. Are there any compressor upgrades that anyone knows about? For the accumulator I was planning to run a stock Motorcraft part and I was planning to go with a parallel flow high efficiency style condenser. Thanks!

 

[david4451]

Did they find a leak? If your ac was working then stopped cooling, like the next day I doubt your compressor suddenly went down. Loss of coolant is likely the problem.

Your ac shop is almost replacing the whole system - expensive!

 

[Mesozoic]

Yeah, they said that something in the compressor internally discharged and that's how the refrigerant was lost. They also said that the orifice is completely gunked up, likely due to degradation of the compressor internals, so that's why a new condenser and accumulator is likely in order. I asked them to give me an estimate of work, but not heard back from them yet. If it does require a bunch of component replacement I can replace everything myself, would just need their services to install new lines (if needed), cleanse the evaporator core, vacuum test and recharge.

 

[donalds]

When I first got my truck I had no a.c. it would loose charge overnight
Put dye in it
Turns out it had a pressure relieve valve that was leaking intermittently
The guy fixed it in like 25 min
May want to look into it

Hope this helps

 

[RandomNerd2000]

I doubt you need new lines, you will however need most of what they mentioned to fix this. I know of some people reusing the condensers but that's not recommended due to metal contamination in the system. The orifice is a common tell tale of a bad compressor, and the accumulator also holds metal when the compressor grenades into the system. I don't personally think the evaporator needs replaced since the orifice generally catches whatever is heading through the system if it doesn't end up in the accumulator or condenser.

Me myself, I've only had to do compressor before due to it self destructing, and I replaced the condenser, accumulator, orifice, and compressor itself. It's been in four years pretty problem free.

 

[Mesozoic]

Yep, I ordered a new Motorcraft compressor and will be replacing the condenser, accumulator, and orifice. Cleaning out the evap and lines, I guess. The condenser gets an upgrade apparently, to a parallel flow high efficiency core instead of the original Piccolo 6mm core - maybe it will function a bit better than stock! (It's always been pretty solid A/C even in the hottest of days).