Can 2003 XJ8 steering leak in main rack be repaired not replaced?

I believe this can be done but you will need to find a specialist and probably will have to remove the steering rack or have it removed and bring it too them for diagnosis and repairs. Sometimes, if it isn’t overly worn, it can be thoroughly cleaned and seals as well as some internal parts replaced to restore functionality and eliminate the leaks. I imagine it would not be cheap and with everything involved in this process, it may be best to replace it with new or a re-manufactured rack.