My elixir brake lever has started to leak air. Not going to fix it as they are rubbish anyway but can’t afford any new brakes. Ido have a set of juicy 3 brakes and I wondered if I can use the working lever from the juicy brakes with the elixir caliper tide me over.

Mixing and matching wont be a problem, but what do you mean by “leaking air”? Air getting into the system? If so are you certain it’s getting in through the lever? Checked all connections?