Pressure with the AC on is about 30 psi, give or take a bit, and off around 75, so yes, it could leak out either side.

Usually the o-rings on the high side go first as it's much hotter over there, but both can fail.

The manifold also doesn't fit absolutely flat, so a leak on the high side could drip oil down onto the low side anwyay, depending on the angle of the compressor.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!