Renault Clio 1200cc, Semi automatic Tiptronic

Can a Hydraulic control unit be repaired with a kit avail from Renault, mine is leaking at both ends where cable runs through.
Can you get a recon HCU,
I’m topping up the reservoir at present, but dont know if I’m overfilling as there isn’t a max mark for level, and getting patches on paving either from leak or filling. Please advise.
Chris