where are you having the issue? at the Haldex pump? or the lines into/out of the OEM pump?
if the (aluminum) threads become damaged (in OEM pump)...then that's not an o-ring problem...though the o-ring will continue to be 'spit out' when pressure allows the steel fitting to loose tension on the o-ring...IF the threads are/were damaged...all o-rings are standard hydaulic stuff...#, 5, #, 6, #, 8, etc...so your local hyd. shop should have plenty...but I would look more closely at the cause of the leak(s)...and not just (continue?) to throw o-rings at a (non) o-ring problem...