Ford Ranger AC Compressor Venting via Pressure Relief Valve

[Autosaver]

Hi,

2013 Ford Ranger.

The following parts were replaced:
1. AC compressor
2. AC condenser
3. Drier filter
4. TX valve
5. Radiator fan clutch
6. Condenser to compressor AC hose

The fan clutch was replaced first & the heater core was by-passed. AC was still warm.
The car was passed onto me & I picked up that condenser, drier filter & TX valve were faulty.
On the day that the condenser, drier filter & TX valve were installed, the compressor clutch stopped working.
A new compressor was installed & when the car was refilled & engine was revved, the AC hose popped.
Installed a new AC hose, vacuum & refilled to spec.
Car was good for about a month.

Came back in & there was no AC gas.
Refilled the system with R134a can.
Using soapy water, I sprayed the components & found a very slow leak from the crimp on the AC hose connecting the compressor to the TX valve.
Also when I revved the engine up, the AC compressor started venting gas through its pressure relief valve.
I assumed that the PAG oil had also leaked out & the lack of oil in the compressor was causing it to overheat & relieve pressure.
Note that the high side pressure was only at 190psi.

Waited a couple of weeks for a replacement hose.
Removed the compressor & there was no oil in it. Turned the compressor by hand & it was not seized. I refilled the compressor with the specified oil level.
Installed AC hose & compressor, vacuumed the system & it held for 15 minutes indicating no leaks.
Refilled the system with one 240g of R134a (system take 625g) & the compressor started venting.
I had a look at the expelled contents & it was oil & dye, no signs of metal debris.
High side pressure was between 150 & 190psi (my memory isn't that great).

I diagnosed it as a faulty AC compressor but I'm also going to remove the condenser & check the drier filter for metal debris.

Anyone else have thoughts or past experience with this type of issue?

[Autosaver]

Bumping for a reply.

I read somewhere on this forum that the pressure relief valves are single use?
Meaning that once they pop you have to replace them?

Is this true?

Wanting to know because I'd rather replace the valve than have to replace the whole compressor.
New compressor costs $1700

[JohnHere]

A pressure relief valve that vents and a hose that burst indicate a dangerous over-pressure situation.

How much oil, in total, does the system contain?

Does the outlet of the condenser contain an Orifice Tube, and does the inlet to the evaporator also contain an OT?

I don't have any A/C specifications for your 2013 Ranger. Is this truck made and sold only in Australia? Regardless, your spec of 625 grams (22 ounces net weight) of R-134a seems about right.

You can in theory re-use a pressure relief valve, but it might leak after it vents the first time. Best to just replace it.

[Autosaver]

Thanks for your reply.

Autodata system says 150ml of PAG46 oil.
The compressor I installed says to put 130ml in it.
Both times I just put 130ml of PAG46 oil.
The R134a cans I use come with added oil, I assume, so I should get close to 150ml.

The hose actually popped after installing the compressor the first time.

The venting occurred when the second hose had leaked all the gas and oil through the ferrule crimp.

As far as a I’m aware, there are no orifice tubes in this system.

This model Ford Ranger comes from Thailand so it is sold in the Asia Pacific market.

[JohnHere]

I'm suspicious about the amount of oil in the system. If it contains much too much, there will be a lot less room for the refrigerant, leading to the over-pressurization symptoms you described.

Some oil undoubtedly blew out when the hose burst and the relief valve vented, but exactly how much is anyone's guess. It might have been a lot less than thought. If so, adding 130ml (4.6 fluid ounces) twice could very well have grossly over-filled the oil because we don't know with any certainty how much remained in the other components.

I hate to say it, but the only way to know for sure is to begin again with a "dry" system, which means flushing the oil out of everything that can be flushed, replacing any lines with mufflers, as well as the Receiver/Dryer. If the condenser is the so-called tube-and-fin style, it too can be flushed, along with the evaporator. The compressor can be emptied of oil (never solvent flushed), and then refilled.

After the total amount called for is oil-balanced, or the total amount of oil is added to the compressor, then you can proceed to evacuating and recharging the system, I presume with R-134a.