‘16 A/C Leak & Recharge - Add New PAG Oil?

Howdy - my ‘16 TRD sport lost A/C recently. The system would run the compressor and makes odd sounds in the cab but zero cold air. I added a small amount of 1234yf (had approx 15-20 psi at lowest point) as well as < 1/4 ounce of UV dye for 1234. Found the leak which is at the pressure sensor and have ordered a new O-ring... see below.

My question is this... After I replace the O-ring and vacuum the system, should I add more Pag oil (PS-D1) to the system, and if so, how much?

thanks in advance.

 

The best bet is measure the oil removed when evacuating the system and add the same amount. Unless there is noticeable oil from the leaking sensor. Than I would suggest removing as much of the oil as possible and then put in the recommended amount.

 

Did you recover what was in the system? if so how much did you recover?

 

Thanks x2. I have not yet vacuumed the system... but understand what you are saving. So essentially measure what I pull out and put that amount back in as new oil? Thanks!

 

yea recover the system and add max freon it should be on one of the underhood labels and add dye and check. Did the A/C fail all of a sudden or gradually OP?

 

It failed gradually... maybe 6 months ago it wasn’t as cold so I topped off using 1/2 a can of Honeywell R1234yf. Ran great after that, nice and cold. It’s been cooler in FL lately so haven’t been running it much but about 2 weeks ago noticed the hissing sound from the dash when turning it on and no cold air at all.

I then added a bit more refrigerant and 1/4 ounce of the dye and found the leak at the pressure sensor. New robin air vac pump came today, manifold is on the way, as well as a new Toyota O-ring. Once I get everything I will replace the O-ring, vacuum the system, and add the new refrigerant and oil per under hood specs. Just not sure how much oil to add back in.

 

any amount under 1 oz should be fine for the dye

 

Is, or was, there a lot of oil where the temp switch leaked? To measure what you get out of the system during recovery, you really need a separator of some sort which most modern AC machines have. I would assume you have access to this kind of equipment. The graduated cylinder in these machines collect and measure the oil. Unfortunately, you won’t get ALL the oil out. You can get most of it though by running the system on high for a bit then immediately recovering and vacuuming the system. Once your in a vacuum (and obviously holding that vacuum) you feed in the oil then charge the refrigerant. Chances are you lost very little oil if your system didn’t completely depressurize. If it wasn’t an oily mess where the leak was I wouldn’t my sweat it. Too much oil is almost as bad as too little.

 

Thanks. I can take it to a shop to have them pull the existing refrigerant out before I make the changes if that gets me an accurate measure of the oil removed. I had planned on venting the system anonymous, opening it up to replace the O-ring, Running the vacuum for 30 mins, then putting in new 1234yf and oil.

As for the leak... There was a bit of oily residue on the A/C line by the pressure gauge for maybe 3-5” per side. Nothing bad on the metal below etc so overall very minimal.