Flamingtaco

Does anyone have access to Ford tech data that can pull the A/C pressure chart for the 2015 3.5eco? I could only find generic R-134A data online, and it's conflicting data, charts range from 150-170 to 225-250 psi at the 80ºF temps we had yesterday. Our oldest vehicle (2010 Fusion 2.5L) was at 150psi. The 2013 Escape 1.6L and 2015 F150 3.5L were about 170psi. Only the Fusion felt week, but I brought all three up to about 220psi where all three seemed happy to push mid 30's out the vents.

Doors and hoods open, max a/c, recirculate.

FredB

2015 2.7 AC, But should be close if not spot on,

Napalm

Regardless of the engine type they should all have the same systems. IE the same compressors run the same evap and same condensors - are based on the cabin size. IE all crew cabs have the same parts - 2.7L, 3.5L. 5.0L - etc etc

as far as I know they are all the same.

Now note the chart - I assume here you are quoting the high side pressures - what were the low side pressures? (discharge or suction side if you want those terms). the low side being too high can be damaging - lead to more leakage. and it's the pressure differential that is as important and the max pressure reading.

Hope that helps matters.

elptxjc

Yeah, if you're going to mess with that, you need to monitor BOTH high and low sides at the same time with the correct equipment, and add refrigerant thru it, to make sure you don't introduce air into the system. And depending how much refrigerant you add, you might need to add a proportional amount of lubricant too. Unless you buy the proper equipment, that kind of job is better to leave it to the pros .

Flamingtaco

Low on all three were low to mid 40's.

I'm disappointed to see the high pressure range that low. My 95 SHO was up to 230ish IIRC, I ran it at the max range high, and adjusted the low side sensor to 20psi. I know the variable valve systems don't need to drop as much on the low line as they maintain an average pressure rather than how the low side cycles up and down with compressor operation in an orifice tube system, but it seems they left a bit on the table on the high side.

I wonder if they are holding back on the pressure to consume less energy for CAFE. Seems they have gotten to the 'every last tenth of a percent counts' point with installing shutters in most of their vehicles (The shutters in our Escape are pretty small compared to the F150's).

Napalm

YOur 95 SHO was still using R-22 refrigerant from the factory. Since around 2002 everyone swapped to R134 and today you see it as R134A,C,F,etc Or Synthetic R134.

basically the class of chemicals that are - R 134 are cross compatible though.

Meanwhile because of the change in chemical - changes it's entropy values etc etc - requires different system pressures, different expansion valves, larger evap . . . . . .

Basically - it's all different now.

Also and this is another wrinkle in 2010 and newer cars some have what's called a variable volume compressor - so it adjusts vs Load and doesn't putout a constant pressure when the pulley is turning. LIkewise it doesn't have a clutch either - so the pulley is always live and inside the body the "pump" is always live not cycling. HOwever it still has an electrical lead - and it gets commands from the computer to pull in or let out a swashplate that varies this compression ratio . . . . . . .

So and I think the F150 has one too - it doesn't always run ____ psi at all loads. So you really do have to run it at certain conditions to stay within the chart span. Which then means you have another variable to play with where you could over fill the system.

So please follow the tech manual. And I think you have that - and looks like you'll be on the right track. capacites and pressure might change on your other vehicles too - so look for those tech sheets also.

tmcolegr

...

idrive

iTrader: (3)

Pretty sure it was R-12, not that it really matters but just for clarification...

Flamingtaco

Don't know where you got your info about years, Napalm, but it is incorrect. The R-134a manifold I have, I purchased for that SHO. R-134a phase in began in 1992, in 1994 it became mandatory. All new US vehicles sold in 1995 had R-134a.

If anyone noticed the conditions I set, I indicated I had recirculate turned on.

At about 85ºF today, I put the manifold on. Numbers were a bit higher than yesterday due to temp, until I shut off recirculate. Pressure went up to 270psi. I recovered gas, bringing it down to an average of 215psi. right at the upper limit of the chart TMCOLEJR provided (Thank You, TMCOLEJR!).

Temp is not bad. It's not like it was before I recovered some gas, but still better than it was running closer to 170psi. I can see how being in the middle of the range (where most shop techs will set it) and not having tinted window results in inadequate cooling when idling on hot temperatures. If I lived in a truly hot state (mid 80's-90's, rarely do we break 100), I'd run another 20psi without batting an eye. As it stands, I don't have to deal with heavy traffic, and the sides and rear are tinted (something over legal, but not limo dark), so sun load isn't bad. I'm good with staying within the limits under these conditions, but I'm definitely going to run the max. We do occasionally drive to hotter climates. I'll look into the front window IR stuff, as the black dash gets pretty hot.

Low pretty much stayed at 45psi, appeared to fluctuate maybe a degree either side, pretty consistent. High fluctuated 3-4psi either side. What I didn't do was adjust the throttle to see how it varies with speed. Temp at the vents drops a good bit by the time it's at double idle speed.

ProjectSHO89

The 95 SHO was R134a, as was the 94. Had two of them, one before and one after my old 89 "project".

R22 was not used.