R134A capacity question

[TORNIT07]

Just competed timing job on my '07 EL. While everything was apart I replaced both AC lines from compressor. Also replaced the desiccant which is inside the condenser. The original lines had been leaking about two years. From everything I could see the system was clean inside. No trash or black stuff. Spotless. I vacuumed the system down for a couple hours & let it sit a few hours. No apparent leaks.

Upon recharge I used the 12 ounce cans & my Robinair gauges. Here comes my question. I added four 12 ounce cans. That's 48 ounces of freon minus whatever little bit remains in hoses...maybe an ounce or so? The cans were totally sucked empty before I removed for the next. Also, I added ONE ounce of PAG oil to the condenser.

The underhood sticker says 1.37 LBS for front ac and 2.00 LBS for AUX (rear) ac. The sticker actually has two different specs for the AUX ac. One is 2.06 LBS and the other is 2.00LbS MAX. I'm going by the later. So the system should take about 53 OUNCES of freon based on the sticker?

I'm about half a can shy of full? It's blowing 40* with outside temp about 80*. The low side reads between 29 and 35/high side between 170 and 250. It fluctuates with electronic clutch fan engagement, but overall pretty stable. I was looking for better info online & saw a chart that said 2007 expy only takes 33 or 36 ounces of freon? I'm just apprehensive to add too much & end up overcharged.

What say the experts? Do I need to add a bit more...or have I already added too much?

 

[07navi]

You are right in there and I guess you know your gauges will fluctuate with the ambient temps. Get a little thermometer that you can stick one of the vents on the driver side and you should be between 40* and 50* (some shoot for the thirties but not needed). Go out on a cool morning and check it out. If you sense and pump slugging let a little out but check out what you have before going farther. Your pressures, temps, and pag oil look good, don't overthink it.

 

[TORNIT07]

Yeah, I may let a little out before I try adding a little. Wish I had a recovery machine. Seems it was actually blowing 38* before I added the last part of can #4. Today it was blowing 42* to 45* but was in the mid 80's & muggy. IDK why the sticker underhood has those capacities for freon.

It is the EL...does it hold that much more over the standard length expedition, or is the evaporators a little larger? I may end up biting the bullet & paying a shop to recover & charge using the machine, just so it's exactly right.

 

[07navi]

Yeah, I may let a little out before I try adding a little. Wish I had a recovery machine. Seems it was actually blowing 38* before I added the last part of can #4. Today it was blowing 42* to 45* but was in the mid 80's & muggy. IDK why the sticker underhood has those capacities for freon.

It is the EL...does it hold that much more over the standard length expedition, or is the evaporators a little larger? I may end up biting the bullet & paying a shop to recover & charge using the machine, just so it's exactly right.

I really wouldn't worry about it, it greatly varies with the ambient temps and if you are getting 45* on a hot day you are doing really well. Save your money, it's not rocket science and adding a little too much won't change anything..

(they haven't used Freon since the late nineties)