Driving with the system dry can cause problems with the pump and in
your case the seal(s) on the rack is probably blown. Replacing the
rack with a rebuilt is expensive - DIY for about $400 and well over $1K
or more.

Another way to blow your seals is to use about any fluid other than the
manufacturer's steering fluids. Using aftermarket steering fluids on a
honda and toyota will probably cause a racks seals to be blown. A
relative saved a few bucks by buying some aftermarket steering fluid
for his Avalon - will cost him over $1K.

Same applies to tranny fluids for a lot of vehicles.