A/C Compressor Blowing Off Refrigerant ???

[MIDNIGHT RIDER]

Last year, I installed a new condenser, new accumulator, new variable orifice valve, and all new o-rings.


I removed all lines and flushed them thoroughly; I flushed the evaporator.


I pulled a vacuum overnight and added new oil and R134a, which the system had been converted to several years ago.




Just a week ago, it was producing 36* dash temps and heavily frosting the line between the compressor and evaporator; also heavily frosting the drier.




Now, for the last few days, when I first turn on the A/C, a large volume of refrigerant spews out of an orifice located on top of the compressor, enough that it drips off the hood.


It will spew for a few seconds and then stop.


Dash temps struggle to get below 50*




What is going on and how do I fix ?


Thanks for reading.

 

[franklin2]

Hey, you are "longrider" on the FTE board correct? Here's what I wrote over there.

Is the oil coming out of the high pressure relief on the compressor? You need to put a set of gauges on it and see if the pressures are really high or the valve is faulty. Harbor Freight has a set and on sale they are not too bad,, and they work good.

 

[junk]

Yeah sounds like the high pressure relief. I've had one blown on my rig also. Does sound like you have a high pressure, but why that's happening now I have no clue. Makes me wonder about a plugging up Variable Orifice tube? I agree you need to get some gages on there.

I've heard that once the High pressure relief pops you need to change them, but I haven't changed mine yet and it seems OK.

-Jeremy

 

[OLDBULL8]

You had the system way overcharged, frosting the low return line is an indication of that. Pressures go up depending on ambient temps. finely the compressor didn't like it and blew off, gotta replace the safety valve now.

 

[MIDNIGHT RIDER]

I am no expert; but, at least on this truck, when it frosts the line, the gauge readings don't ever indicate high pressures; in fact, once it starts frosting, the numbers start going down and also the dash vent temperatures go down as well; when I have no frost, I have poor dash temperatures.

After seeing what was going on, I connected the gauges to investigate.


Ambient air temperature of 90*, in full sun, on a normal sickeningly humid Kentucky day.


Refrigerant had lost down to about 16 Lo Side.


Engine at 1200-RPM, blower-fan on low (which is where I always get the coldest dash readings), condenser pusher fans on, direct-drive engine fan sucking gravels off the driveway.


I added one can refrigerant and brought readings to 32 Lo Side, 220 Hi Side, with absolutely no improvement in performance; no hint of frosting; very poor dash temperature of 57*


I drove it about twenty miles round trip and it was livable in the cab, but nothing to brag about.


Blower-fan on high makes no difference in cooling and actually raises vent temperature; turning on full-voltage to blower-fan, which about quadruples fan speed/power does not help.


Before this blowing off business began, it would freeze my skin to the accumulator/drier and frost heavily from evaporator to compressor; now, the accumulator barely gets cool at all.


It only does this refrigerant spewing at initial engagement of compressor and lasts for a few seconds before it stops blowing off.


Once it does this first bit of spewing, it will not do it again so long as the compressor remains engaged.




Always before, the engine never gave a hint that it ever knew the A/C had been engaged; now, I can notice a slight bog in engine RPM at the moment the compressor engages.




Whatever is going on, putting the refrigerant readings to where they have always before yielded good results has not helped matters a bit.


Plus, no refrigerant had been added to bring on this crisis; everything was fine one day and all wrong the next.

Thanks for reading.

 

[typ4]

sounds like the orifice tube took a dump. Dont get the cheapest one.

 

[MIDNIGHT RIDER]

sounds like the orifice tube took a dump. Dont get the cheapest one.

Which one do you recommend ?

I thought the one I had was the one to get, but that don't mean it couldn't fail.

 

[BDCarrillo]

Orange for variable valve, red for fixed

 

[Vevo]

This happened to me a number of years back. The problem was a weak fan clutch. Replaced it, recharged the system, and the a/c problem was resolved. Hope this helps.


Sent from my iPhone using Tapatalk

 

[franklin2]

My high side relief popped when I forgot to interlock the electric fans with the A/C. It popped but after I figured out what happened and fixed it it's still working to this day with the relief valve that popped.

 

[MIDNIGHT RIDER]

Both pusher fans were howling like banshees and there is no clutch on any of my fans.

Due to the circumstances, I am tending to lean toward typ4's diagnosis, or a restriction somewhere else, although the most likely point of restriction is the orifice valve.

I was a good boy and done all the right things and should have had problem-free A/C for several years and now this happens.....


I wish I could get this truck's A/C to do so well as the wife's 1991 Dodge/Cummins; I put in a can about twice a year and can easily show below-freezing dash temperatures; it can get bone-cracking cold in that truck on a 100* day and it hasn't had any special treatment other that direct-drive fan.

 

[ironworker40]

Frosting of the lines usually indicates a low charge. As you add refrigerant evaporator temps will rise. If you popped the safety you had high high side pressure which can be caused by the fan clutch but you have none and as I understand two electric pusher fans.Cheack radiator and condenser and the area in between for leaves ect. Also blue orfice is usually stock and if you went with red or orange they are smaller which will raise high side pressures. I assume all fans are good with no broken blades. Variable orfice tube are know for malfunctioning. I would look there.

 

[The Warden]

I wish I could get this truck's A/C to do so well as the wife's 1991 Dodge/Cummins; I put in a can about twice a year and can easily show below-freezing dash temperatures; it can get bone-cracking cold in that truck on a 100* day and it hasn't had any special treatment other that direct-drive fan.

If memory serves, you did the 6BT conversion yourself. Did you use the Dodge a/c compressor, or did you use the Ford a/c compressor?

 

[typ4]

Pull the orifice tube, if it has black crap in it you have hoses coming apart. do you have good dash airflow, evap could have crap on it.

 

[MIDNIGHT RIDER]

If memory serves, you did the 6BT conversion yourself. Did you use the Dodge a/c compressor, or did you use the Ford a/c compressor?

The entire A/C system is original 1985 Ford factory air, with some new direct replacement parts here and there; it still has the original compressor and clutch.

I never even evacuated/disturbed the refrigerant charge when I swapped engines.