I want to top off my Expedition AC. It doesn’t cool. Somewhere around 2018 it stopped cooling well and I never took care of it. We basically had it vac and refilled and it holds cold for a couple of years. It’s time to do that again but I want to do it myself. My F150 all original AC starting doing this and I’ve been topping it off based on temp and pressure charts and it’s been working awesome. It’s a 2002. I am totally and completely aware that this is not the preferred method and vacuuming it out and weighing to refill is. But at 400,000 miles, I don’t care.
The expedition is a TXV system and my F150 is a FOT. My question is, do I need to know or do anything different when reading my gauges on the TXV expedition system or just too off the same way with my gauges and pressure chart? My goal is to get sim cooler temps than 60 degrees. It’s 107 in the shade and kids and wife need it a little cooler.
I buy r134a by the case and am willing to use my yellow jackets for something more than one truck and a dust collection.
Agdodge4x4 wrote: ↑Sun Jul 16, 2023 5:47 am
I want to top off my Expedition AC. It doesn’t cool. Somewhere around 2018 it stopped cooling well and I never took care of it.
I think you need to get a new drier, likely moisture has entered your system over the last 5 years. And it's time to find and fix the leak, and get the system evacuated and filled by weight.
There is no difference in charging methods and end points whether TXV or OT. The charts can be misleading. We don't use them. You usually want to aim for about 30-40 lo and 275 hi under your conditions, with RPM at 1500-1800, doors open, max cool, max fan, recirc (max load).
Cusser has a good point worth considering.
And because of the methods used so far, you are probably getting low on oil, which could be catastrophic. If refrigerant is escaping, usually oil is also.
In fact, when techs look for a leak, they first look for an oil spot on surrounding areas which is a tell-tale
When considering your next auto A/C purchase, please consider the site that supports you:www.ACKits.com
tbirdtbird wrote: ↑Sun Jul 16, 2023 8:02 am
There is no difference in charging methods and end points whether TXV or OT. The charts can be misleading. We don't use them. You usually want to aim for about 30-40 lo and 275 hi under your conditions, with RPM at 1500-1800, doors open, max cool, max fan, recirc (max load).
Cusser has a good point worth considering.
And because of the methods used so far, you are probably getting low on oil, which could be catastrophic. If refrigerant is escaping, usually oil is also.
In fact, when techs look for a leak, they first look for an oil spot on surrounding areas which is a tell-tale
Ok. Thanks for the info. The last tech added dye, but to date have not been able to locate a leak from an oil stain or otherwise. Thanks for the info. I’d like to get past the summer and kick that can down the road.
The systems have never leaked completely out. It has always had pressure and cooled to some degree. As such, the commentary about air getting in doesn’t make much sense to me. How does that happen if the system is under constant pressure? The oil concern I believe is quite valid, however.
Evaporators win the award for being the most likely culprit to leak. Sniff the drain tube.
Also, put a shower cap on the comp and leave it for the night, then stuff a sniffer probe in there in the morning and that will tell you if it is the shaft seal
When considering your next auto A/C purchase, please consider the site that supports you:www.ACKits.com
This system running full bore and idle
53 lo, 235 high, ambient temp 107
At 1500 rpm:
35lo, 275 high. 107 ambient.
I understand there is a right way to do this. However, I need to do some thing right now to get me through the week until I can go to the shop. If this thing dies by the end of the week and it cost me three grand to fix it, so be it. I’m willing to take that risk. It’s 107° in the shade where we are. And that’s not an exaggeration. That is the ambient air temperature. A family and six hour drives. Need to fix now.
Right now you are in a safe operating area for 107 ambient and those pressures. As many have pointed out you have no idea if there is enough oil in the system for a long and happy life.
I understand the circumstances mean taking a chance. It has been 112f and over here for a while.
bohica2xo wrote: ↑Mon Jul 17, 2023 3:53 pm
The 1500 rpm number is the important stuff.
Right now you are in a safe operating area for 107 ambient and those pressures. As many have pointed out you have no idea if there is enough oil in the system for a long and happy life.
I understand the circumstances mean taking a chance. It has been 112f and over here for a while.
Hope you get it sorted out.
I ran with it. Topped off. I when to the “minimum” side of the numbers. It cools. The back has cold air.
It goes to the shop next Monday. I can be without it for a week then. It’s already got dye so hopefully they can find the leak and knock it out.
AC starting doing this and I’ve been topping it off based on temp and pressure charts and it’s been working awesome. It’s a 2002. I am totally and completely aware that this is not the preferred method and vacuuming it out and weighing to refill is. But at 400,000 miles, I don’t care. 
