sorry to hear that mate, from what i've been told brake fuild has no lub properties, and cuts into the bearings and rack if put into the power steering system, hence the brakeing system working off a vacume pump....your best be is getting hold of a salvage rack and pump,
my mate changed the pump but had small traces of brake fliud in the rack, and did'nt get it sorted until both where changed,
i've been told by a friend of my dads who was a master tech at volvo, the best way to flush a contaminated system is to, use boiling water and a good degreaseing agent i.e: some sort of oven cleaning spray, mix the water and degreaser together and run it thought your system with the car on as your turn the steering lock to lock, and let the return pipe to the power steering resevor drain out (dont let the returning water go back into the system) oh and block the return hold on the tank,
this should clean out the system, seals and bearings, if the damage is'nt that bad,
leave the system once the water has flushed out completely and flush it once more with boiling hot water, the hotter the better, the water will dry quickly and flush it once with power steering fluid, and fill with new fluid.....hopefully sorted, but this is a 50/50 thing
worth a try though