I seem to have a leak from my steering rack - thought it was coming from front diff but now definitely can see is from the rack. My question is, can these be rebuilt? Is it worth using a leak fix fluid?

Alternatively are there rebuilt units available?

Any advice greatly received as always….. 2007 Range Rover Vogue 3.6 TDV8

Shortly after buying my 4.4 it had to be booked in originally for a diff seal leaking and like yours it was discovered that it was actually the steering rack.
I was lucky that it had a new rack fitted under warranty.
From what I believe the seals arn't available to us DIY'ers.
There are reconditioned units available from about £350 upwards but I don't think it's an easy job to do yourself.