Updated with current EVM suit documentation:
I was finally able to get the full EMU Systems Workbook (click here to download - 22 MB, this document is awesome and chock full of info too!)
There is all the info you could want on leakage on pages 1-23 and 1-24 (PDF pages 39 and 40) I have circled the relevant number below (in an excerpt from page 1-24
I have just now received an answer to my FOIA request from NASA requesting documents on the current generation space suits. One of the documents of interest was the Extravehicular Mobility Unit Systems Training Workbook (click here to download - 52 MB), it contains a ton of information on the current generation space suits.
If you look on page 131, it states that the automated leak check fails if the suit is losing more than $0.3\ psi/min$, with a nominal suit pressure of $4.3 \pm0.1\ psid$. Unfortunately, the suit volume is not in this document so the mass flow cannot be determined.
The "Apollo Operations Handbook Extravehicular Mobility Unit" (click here to download - 4.4 MB), Revision 5, Table 2-I quotes the Maximum leak rate at 180 cubic centimeters per minute.
The Extravehicular Mobility Unit is the suit used for the Lunar Landings (the linked document contains a wealth of awesome information).
Though the current generation of suits is also called the Extravehicular Mobility Unit and I cannot find out what the relationship between the Apollo era suits and the current generation ones.
Extravehicular Mobility Unit
Table 2-I, (scc stands for Standard Cubic Centimeters)