According the section 18-005 of the FSM, the cooler connection is on the upstream (dirty) side of the filter before the oil returns to the pan (same as the gauge connection). The pressure relief on the oil pump is set at 7 bars and the bypass around the oil filter is set at 3.5 bars. I would assume that the oil cooler can see at least 3.5 bars (53 psig), but probably not more than 7 bars (105 psig), depending on temperature, rpm, and the pressure drop through the filter and/or bypass.