A/C accumulator and A/C pressure cut-off switch attachment

[CoyoteWilee]

Good day, I have a '94 Explorer 4.0 v6 4 door that had the R134 A/C system conversion done on it many moons ago. Just over a year ago I had the A/C compressor and accumulator replaced along with the pressure cut-off switch attached to it. The A/C started to not cool as well a few months ago and went to warm air after that. I checked the pressure and saw that the pressure was low on the system. I put some R134 with dye into the system and found the bolt attaching the pressure switch to the accumulator was where the leak was. Did the UV lamp sweep on the rest of the system and found no other culprits. It's leaking on the switch part itself on the bolt part that, I think, screws into the accumulator from what I see. I do know about getting the system evac'd and such due to moisture concerns, but is this relatively easy to replace with disconnecting the wire plug from the switch and unbolting with a wrench? And I believe it's a high pressure cut-off switch? Thank you.

 

[Maniak]

The pressure switch that is on the accumulator (some people call it the receiver/dryer but IIRC is not technically correct).. is screwed onto a shrader valve. That means you can remove the switch and install another one without loosing any more r-134.

~Mark

 

[CoyoteWilee]

If I'm not mistaken from what I see, it appears that this 'shrader valve' may have a slight crack in it, and the dye is slowly seeping out from it - little bit of bubbles coming out from the tan colored piece attachment. Is the shrader valve the tan piece (probably metal for the high quality piece) in between the accumulator and the switch - and looks like you can take a wrench to it? I just don't wish to play roulette with a pressurized R134 system if I disconnect something I shouldn't. Note: this bolt piece appears to attach to the switch part - did reference to what it looks like thru autozone and oreilly. Thanks!

 

[TedJ]

The shrader valve is in the metal nipple that the plastic body of the pressure switch screws onto. Now technically it is supposed to seal so that if you remove the low pressure switch, no refrigerant escapes, (works just like a tire valve) but it may or may not work. Mine didn't work all the way, so I had to stuff the new low pressure switch on there in a hurry. Have the switch ready and just swap them real quick. (and wear safety glasses)

 

[CoyoteWilee]

Good info to know. I'll be making a tackle on this in a day or two and will post how it went. This board has been quite a help for me between my '94 Explorer and my '99 Ranger. I've gotten a few issues resolved thru searching the post, and a lot of good info out of it too. Thanks to all!

 

[CoyoteWilee]

Wet and soggy weather prevails - not ideal for working on the A/C. Will have to wait until about Tuesday before attempting. Don't like acid R134 in the system.

 

[smegun]

the switch and the access port are on the accumulator my access port was hissing and leaking after adding a can of 134 i followed the directions but when i got home it was a leaking i bought repair valves and the little wrench that turns them here your saying that the little dart goes in the switch and not the access port ? duh i was trying to screw in a light bulb (tighten up the access port but didnt land a punch lost most my 134



well i found the schrader under the switch on the accumulator it was a few turns from being tight easy enough but i can still feel leaking refrigerant under the access port ... its time to replace the accumulator probobly its a little rusty switch looks old too im not shure if the cap has to be on to be air tight even :/ what is the cause of the access port leaking i did have air for a while