Do I add AC oil

So I’m changing a couple O-rings that are under my quick disconnects going through the firewall on my truck. It must’ve had a slow leak. As of now I’m not going to add oil…

First am I wrong? I’m not changing any major component. I am using the vacuum pump to make sure all the leaks are gone once the O-rings are replaced.

Lastly besides changing the compressor, dryer accumulator, condenser or evaporator is there any other time you should add oil? Is there a guideline on when and when not to add oil?

I always add an ounce of oil when just replacing O-rings.


Manufactures specify how much oil to add per component change. Sometimes it’s written on instructions on component.

It usually goes like this,

Compressor=Refer to manufacturer for capacity.

Condenser=2 ounces

Evaporator=1 ounce

Receiver/dryer=1 ounce

Hose assembly=1 ounce


So even tho the original line is going back on, you would personally still add an ounce? Is there a place average Joe’s can see info like this incase I’m asked in the future?

Thanks for your help

No component change. Just 3 O-rings, all on the same fitting.