Which A/C port is the low port?

[mole]

I have a 1995 325i.

I see two ports on the passenger side of the engine bay. There is a port near the firewall and a port near the coolant tank.

Which is it?

[mole]

The pictures I see have the two ports right next to each other.. but mine are on the opposite sides of the engine.

[al_r]

Firewall, low side is the smaller of the two.

[mole]

yep thanks
psi was around around 35psi in 100 degree temp.. i added it until about 40psi.

[choffa]

You're right in the range @ 100 ambient:

http://www.ackits.com/index.cfm?fuseaction=Chart