AC Sanity Check

[410Fortune]

Couple of things
If your compressor is short cycling and you suspect it’s low on refrigerant, we jumper the low pressure switch. If compressor stays on then you know you found your issue
Low refrigerant

Same Goes for the high pressure switch
If it is short cycling due to excessive pressure
Buildup then jumper the high pressure switch to confirm

Always clean or replace the orrofice tube when serving the system

I have had good luck with 4 seasons aftermarket parts. All compressors ship with the note “this compressor shipped dry blah blah… but our style compressors always come charged with oil which is quite obvious when you unbox it and see the plug on the back

The 5.0 charge is 30-34 oz almost exact same charge as sohc engine

The high and low
Pressure port schrader valves are often the source of small leaks. I’ve had good luck repairing them by taking it apart and cleaning. Or replace the little valve with parts FromDonor truck

Junkyard find a good dual
Core radiator and flush that sucker out. Prices for new are ridiculous and the parts are usually crap
The fully tig welded all aluminum units on eBay are hit or miss I’ve had them last 5 or 8 years and two of them less then a year before leaks develop…

 

[C420sailor]

Yeah the Four Seasons valves are ****. My high pressure service port is very very slowly leaking, just like the FS lines on my other truck. New out of box, it seems like they all do this…and the OEM valves are a different size…so it’s a PITA to find good replacements

Annoying

I have a new rad on the way…need to get this thing back on the road, as it’s my daily driver. Once that happens, I’ll keep an eye out in the JY for an OEM spare

@donalds 100% right…unfortunately I don’t have any on hand. This will have to do for now.

The joys of these old rigs

 

[410Fortune]

Put some oil on it and depress it really quick sometimes open and close them with a little pb blaster and they will seal up

 

[C420sailor]

I’ll definitely try the oil trick!

JB weld on the radiator held on a pressure test to 16psi

Out test driving now. Gotta get to work today, cross your fingers!

 

[C420sailor]

Okay, circling back to the original part of this thread—the 5.0 AC system

I suspected a very very slow bubbling on the high pressure service port. Turns out, I was wrong.

I bought a real nice Fieldpiece refrigerant detector. It lights up where the suction line connects to the accumulator/drier—the joint with the three o-rings. I disconnected rhe hose and there is visual sign of a very slow leak past the rings. Rings look good.

Replaced the rings. Still leaks. On a nitrogen charge with a trace of refrigerant, lights up the detector.

What I noticed was that the Four seasons line easily popped into the four seasons accumulator. When I did my other truck a few months ago with a four seasons hose and MOTORCRAFT accumulator, it was a much tighter connection.

I’m leaning toward this being a case of a defective accumulator, with the hole being too large to properly crush the o-rings.

Got a new accumulator on the way—a motorcraft. Will advise.

 

[C420sailor]

Installed the new Motorcraft accumulator/drier. I mic’d the opening for the hose connection and the Motorcraft was .005-.007” smaller in diameter. The fit definitely felt tighter and more positive. She’s holding pressure, no leaks detected by the electronic leak detector. Vacuuming down now.

Normally I’d say this is a case of stacked tolerances between two different manufacturers, but given that the issue was with both Four Seasons products…they either designed in too much tolerance, or it was a QA/QC issue on the accumulator.

Buy Motorcraft if you can……

 

[C420sailor]

Tore back into the 5.0…she was slowly bleeding pressure and I could smell it in the vents on start.

So, 2-3 years ago I replaced the entire system minus the evaporator with Four Seasons parts. I flushed the evaporator thoroughly and installed a new orifice tube.

Anyway, today I went to install a new evaporator. Pulled out the old orifice tube and it was completely plugged up. Full of metal.

I had a significant pressure differential from day one—the compressor probably rapidly sent metal into the orifice tube, clogging it up.

That piece of **** Four Seasons compressor. I recently had a problem with one of their driers being out of spec too.

Junk. Absolute Chinesium junk. Avoid at all costs.