Air Conditioning system leak 1994 4.0L Ranger.

[JMF661]

Hello all,

I have a '94 Ranger 4.0L. A/C system did not work on purchase, compressor would not engage. I decided to start by adding R-134a until system pressure was within specification, compressor came on as expected, cold air out of the cabin vents. I was really hoping I got off easy. Fast forward a few days of truck sitting, A/C compressor was intermittently engaging, upon removing both service caps I could feel/see/hear refrigerant escaping. Now comes my request for experience with these systems. As I understand it the service valves can not be replaced in this system, the entire hose assembly needs to be replaced. My concern is these valves have failed due to lack of use, no lubrication, cracking, and general degradation of the rubber o-ring components in the system. Should I move forward with an entire A/C system restoration, new hoses and o-rings, or would it be best to simply replace known leaking service port hoses and go from there? I thought it odd that both service valves are leaking, but I have very limited experience with A/C systems, maybe this is a common occurrence?

Anyhow, any knowledge or tips would be greatly appreciated!

Thanks!

 

[4x4junkie]

Being that the truck is 25, 26 years old, I would suggest replace all of the rubber parts in the system (hoses, o-rings, etc.). If the compressor shows any signs of oil around the seal between the two halves of the compressor body, or around the input shaft seal area, I'd suggest replace the compressor too (unless rebuild/reseal kits can be had for it, I can't recall having ever seen any though). Accumulator/drier & orifice tube should always be replaced too.

The evaporator and condenser coils can be flushed and reused (that is, unless you find heavy black goo in the system (failed compressor), then the condenser coil must also be replaced. That gunk & grit cannot be flushed out of it so that it doesn't present a risk of causing the new compressor to fail).

 

[JMF661]

Thanks for the info. You’re probably correct in that it would be better to rework the entire system rather than chasing issue after issue. I’ll have to do a more thorough inspection and order some parts.

 

[Josh B]

Are you sure the system is R-134a ?

 

[RobbieD]

R-134a started in the '94 models, and has different low side service port than the R-12 systems. The AC system service specs will be on a sticker on the evaporator housing (engine bay, passenger side), if it's still there. Both my '94 Explorer (BD 9/83) and '94 Ranger (BD 11/94) were built with R-134a systems.

Agree completely with 4x4junkie's advice. Replacing everything except the evaporator with new parts on my Explorer ran about $430, from RockAuto about three years ago (parts only; I installed them).

 

[telsar]

You can just buy the valves in the service ports, but you will loose all your refrigerant.

 

[JMF661]

The specification sticker is still present on the housing, it does indicate the system uses R-134A.

 

[JMF661]

You can just buy the valves in the service ports, but you will loose all your refrigerant.

The low side port nearest to the evaporator seems to be a more typical check valve which I seen before, the high side valve is a rubber type with no visible metal stem protruding upward.