A/C Freon Pressures
Thread Starter
Senior Member
Joined: Aug 2014
Posts: 338
Likes: 20
From: Charlotte, NC
2005 E320 CDI, 2015 GLA 250
A/C Freon Pressures
Does anybody have the recommended freon pressure ranges for the 2005 E320? I’ve search several forums and my MB troubleshooting DVD to no avail.
Or maybe it just the same as for any other MB or any other brand of car.
I’m guessing it will look like a table with columns of Ambient temp, low pressure range, high pressure range, and maybe something else.
Rows will be ambient temps etc.
Thank you,
Peter
Or maybe it just the same as for any other MB or any other brand of car.
I’m guessing it will look like a table with columns of Ambient temp, low pressure range, high pressure range, and maybe something else.
Rows will be ambient temps etc.
Thank you,
Peter
Junior Member
Joined: Aug 2018
Posts: 52
Likes: 4
2004 E500 wagon
Thread Starter
Senior Member
Joined: Aug 2014
Posts: 338
Likes: 20
From: Charlotte, NC
2005 E320 CDI, 2015 GLA 250
Interesting chart but it doesn’t say what the high and low pressures are, just a static pressure. My concern is that there is some sort of affect of the MB expansion valve on the high and low pressures.
Mine are 32psi low and 178psi high at 80F.
Peter
Mine are 32psi low and 178psi high at 80F.
Peter
Junior Member
Joined: Aug 2018
Posts: 52
Likes: 4
2004 E500 wagon
Static pressure is the easiest and most precise to measure that you have the correct amount of refrigerant in the system. With the car having rested for a few hours, put your gauges on, make sure the pressures have equalized, and measure the temp at ambient under the hood.
Dynamic pressures have a range. They are less precise. No, there's not that much difference in the expansion valve, or the system won't work. It's simple gas dynamics.
Here's a high low pressure chart.
https://www.acprocold.com/faq/r-134a...ressure-chart/
Dynamic pressures have a range. They are less precise. No, there's not that much difference in the expansion valve, or the system won't work. It's simple gas dynamics.
Here's a high low pressure chart.
https://www.acprocold.com/faq/r-134a...ressure-chart/
Member
Joined: Mar 2018
Posts: 112
Likes: 27
From: Atlanta, GA
'07 E350 (W211)
I seem to recall reading something in this forum about needing to run the engine at ~2k RPM and taking the reading while at that RPM. I don't know the details and it might be BS, but I know I read it in here somewhere.
