High Side vs. Low Side Fittings on Compressor?

Was going to try and put some refrigerant in my system to check the status of my AC. Unlike most old R12 systems I've seen, both fittings are on the compressor and both have the same sized threaded fittings.

Does anyone know which of the fittings is High Side vs. Low Side? The "Upper" fitting (closest to the front) has as slightly smaller line so I assume that's the low side.

I can't seem to find this specific number anywhere.

Anyone who has done an R-134 conversion I'd love to hear.

Thanks!

 

Image Unavailable, Please Login


Seems the upper is for charging the sistem.
Guido

 

No it is not. The smaller fitting is the high pressure side. The larger fitting is low pressure side and is for charging.

 

So both fittings/connections are the same size on my compressor. The hose going to the forward/upper fitting is slightly smaller diameter than the lower, larger hose.

So be clear both fittings are the same, it's the hose sizes which are different.

 

R12 system has same fittings. The smaller hose is the high pressure side.

 

Yeah even looking at the diagram, the image of the gauge (I) is a low-pressure gauge.

I ordered some 90 deg R12 adapter fittings and will throw some refrigerant in and see what happens!

 

What filling port is it then ? That marked with S or the other ?
Here is an intresting manual for the York compressors :
http://www.240.se/litteratur/york.pdf

Guido

 

I would put a new drier in first. It's possible that material could come out of the old drier and clog the refrigerant lines.

Also, refrigerant usually leaks out of O rings. If you're serious about getting the system working, you should replace all the O rings you can find. You can get these in a generic kit with a bunch of different sizes. Likely the old compressor is going to have seals that leak, and needs to be replaced. The system should be evacuated with a pump before you add refrigerant, and the correct quantity of oil.

 

All good advice. I actually have a professional Robinair AC diagnostics and recharge machine. So recharging the system is basically free for me. Given that, my method for a car like this (based on many of my 30+ year mechanic friends advice) is to charge up the unit first before breaking old seals. This system has probably been unused for a decade and my have naturally leaked out over a time like that. So I pull a vacuum for 30min, let the system hold for 10min, then fill with refrigerant and dye. If those tests pass it will let me know the overall condition of the system faster then chasing down o-rings that I may have distrubed.

If the system takes (and holds) the charge then I'll start a more thorough component change little-by-little replacing o-rings, driers. etc.

 

When I got my car a year ago, the A/C was inoperative. I knew the car had just had a belt service, so I assumed the compressor had been removed at the time, and no new charge had been added. I bought a few cans of vintage R12 off of ebay and filled up the system and it has worked fine ever since. I remember getting to the port was a pain. I'm pretty sure I had to do it through the wheel well access. IIRC, I attached the fill hose to the port with the larger hose, assuming it meant lower pressure. As you can readily tell, I'm not an A/C expert, but it has continued to work through one hot Florida summer. Maybe I just got lucky, lol.

 

Anyone know where the ports are on a Mondial T? I can see the blue capped port next to compressor but I can’t find the red capped port.


Sent from my iPad using FerrariChat.com mobile app

 

Thanks for the York Manuel. I now know how to check the oillevel[emoji3]

 

This might help. It’s the fitting lowest and closest to the engine that I used. As you can see, it has”SUC” cast into it, so I assumed that meant suction. This is an 87 3.2.
Image Unavailable, Please Login

 

Next to the compressor, under the car. Yes, really accessible.