Explorer AC Issues (long post)

[CraigK]

This is an Explorer issue, not a Ranger/BII one, but I thought it best to post here. Here’s my issue. Any insight into the problem or questions would be appreciated.

1994 Ford Explorer Sport (in otherwise excellent condition), AC not working. (Temperature to 97°F yesterday and forecast for 102°F today.) The system has a refrigerant leak. If I hook up a can of R134a to an empty system and run the engine, within a few minutes the compressor begins to click on and off, in very short on cycles. Then an audible hiss is heard, somewhere in the vicinity of where the discharge from the compressor enters the condenser (I think). I have tried using R-134a with UV dye, and even with the special light and glasses, cannot locate the leak. (But I can still hear the hissing – very frustrating.) No easy-to-see joints, hoses connections etc. show any sign of leakage. Judging by the hissing sound, it seems to be located behind the tranny cooler. I cannot properly see where the compressor discharge enters the condenser.

An additional clue is this odd behavior: when adding freon+UV dye from empty, the compressor begins to cycle on/off, with the on cycle time increasing slightly as the freon enters the system. (This is the normal behavior I’ve observed when adding Freon to ~empty systems.) But instead of this continuing, with longer on cycles, and rising charge (as indicated by the cheesygauge on the freon addition spout), the compressor stops even the short cycles, and no more freon enters the system, even though the cheesygauge indicates a less than normal charge (pressure) in the system.

So, here’s a few specific questions:

1) How do I tell the “factory AC system” from the “Dealer added” AC system? Parts catalogs indicate two types of systems.

2) What are the steps involved in accessing the condenser? Does the radiator itself have to be removed? Can I just remove the grill, then the tranny cooler to access/see where the discharge side hose enters the condenser? What is involved in complete removal of the condenser? Again, can this be done from the front without radiator removal?

I think that if I had better access to the condenser, especially where the lines enter and exit the unit, I might be able to pinpoint the ^&$#%&^$&^! leak. But I don’t want to do extensive work until I have parts on hand (new condenser and discharge lines), but don’t want to order these expensive parts (RockAuto has the best prices) until I know where the leak is and what the problem is. Also, could the odd behavior described above indicate a plugged system?

Apologies for the run-on post, but I could really use some help.
Thanks.

CraigK

 

[Explorin94]

The radiator can be leaned toward the engine (in most cases) and the Condenser can be removed that way.

 

[Earl43P]

With a leak that large (audible) you should be able to see witness marks where the refrigerant is escaping from. It'll carry oil out with it and that oil residue will collect dirt and / or look wet.

http://www.autoacforum.com/
http://www.autoacforum.com/speclisting.pdf

Hit up that second link to see how much oil your system holds. You will ABSOLUTELY need to add "some" oil from your leak plus "more" for whatever component you end up replacing (sounds like your condensor took a hit from a rock).

Bare minimum, add a 3 oz. can of oil no matter what. Then listen for ugly compressor noises and add more as warranted.

The only "dealer installed" systems I've ever seen (years ago) hang lower from the PS dash. A quick trip to a JY to look at other Explorers should answer that question. Someone else may have a better discrimination of how to tell.

I'll add this: If you replace a part (condensor or line), take the added step of replacing the receiver/dryer and orifice tube. Inspection of the old orifice tube (pull it straight out, no twisting) will tell you the condition of the compressor (look for black particulates in the screens = impending Black Death).

You can overcome the short-cycling of the compressor clutch by jumpering the cycling switch connector pins. This tip is handy when servicing an empty system.

 

[4x4junkie]

Discharge side enters the condenser at the top-driverside.

Having a severe leak like you describe means the system likely has also been exposed to contaminants entering the leak as well (air, moisture, dirt, etc), which could be a cause for the erratic behavior you mentioned.

I suggest removing the condenser and pressure testing it if you suspect that might be where the leak is.
It's also possible the compressor could've been damaged too if you've been at it for awhile on this, though if everything is still clean inside the suction/discharge manifolds, it may still be serviceable.