Sure, I sometimes fail under pressure too, but usually that only makes me uncomfortable, not the people around me too....

Sorry for that poor attempt at humor. We are soon to have a new driver in the house and she has a 2003 Escape with the 3.0L Duratec. It has an interesting issue with the air conditioning system. I evacuated the system and kept pulling a vacuum for a bit over half an hour. Then I shut the valves on the manifold gauge to the pump and shut off the pump. After 5 hours I checked at the vacuum had only increased (less vacuum) by 1 in-Hg. I figured that was in the noise and proceeded to charge the system with the correct amount of R-134a. The A/C worked GREAT - for about 2 days. On day 3 or 4 I checked and the compressor clutch would not engage. I put the manifold gauges on again and it was pretty much empty. So I again pulled a vacuum for 30 minutes and close the valves, and again the vacuum help. While pulling the vacuum I got out the UV light, but unfortunately everything glows since the oil system also has dye in it to determine if the primary oil leak is valve covers or one of the other common oil leaks. So after seeing the vacuum was holding again, I again charged the system and got out the sniffers. I used two different sniffers and neither one seemed to indicate any leaks, even from the vents or in the cabin. The A/C worked great again, but was empty after only a few days. So again I confirmed the system holds vacuum, which it still does.

Then I decided to use compressed air to pressurize the system. Pressurizing using the manifold set I was able to see that the pressure leaks down very quickly. It seems to stabilize around 8 psi which seems like it would be a pretty sizeable leak, but I was not able to hear it. I guess maybe I should try the soap water soak to see if I get bubbles, I didn't think about that at the time. But it also seems like if it's something that holds vacuum but not pressure it's probably not a hard line, receiver, evaporate, or condenser issue, but likely a seal or rubber hose.

Does this type of leak happen to be common on the platform and someone can give me some tips on where I might want to look first? Does anyone have some ideas that might suggest I should be considering something other than seals and rubber hoses? Is there a more effective way to try to spot the leak on an engine bay that is already covered in oil residue? FWIW, I did check the front and back of the condenser to the extent possible without removing it and it doesn't glow or look like it has been leaking oil anywhere.

-Rod

 

If you live in a 'salt' state, you may have a rusted accumulator. Soapy water would be my tool of choice. Back when, the O-rings at the fittings would wiggle and get worn out. Using Nylog helped when the O-rings were replaced. The worst thing it could be is the evaporator, but you indicate a sniffer found nothing. Did you check at the condensate drain on the front side of the firewall near the passenger feet area? I'd sniff and also use a black light on the rubber drain fitting.
tom

 

Thank you for the reply!

I didn't think to check the drain for signs of the dye, I'll do that! I also bought a full set of nitrile o-rings for the Escape so I may go through and replace them all when I have the energy and motivation to do so. We do use salt in the winter here, but the vehicle spent all but the past 3 years in Arizona so there are virtually still no signs of corrosion on the vehicle, even where the clear coat has taken a beating. But I will check the bottom of the accumulator. Along with the o-ring kit I bought a new orifice tube so before replacing that I'll check the condition of the receiver/drier.

-Rod

 

Check the high and low side ports (schrader valves) for the leak.

Easy to dismiss any dye observed on the low side port as it might be thought to be from injecting the dye as one expects it to be there. Happened to me once with a dodge Caravan.

 

Expansion valves can get weak springs and vent to atmosphere under pressure too

 

I did replace the Schrader valves in both fittings previously, even though they didn't seem to be leaking according to the sniffer, and purchased new caps as well with o-ring seals. In the case of this Escape, the dye is easy to dismiss since the engine oil dye is the same color and leaks almost everyway. The underside of the Escape with a UV light at night looks like a rave party.

-Rod

 

Oh, interesting. I'll have to check that out. When I'm in replacing seals I probably should just plan to replace the TXV at the same time.

-Rod