Take the nipples out and clean up/check. refit them with a bit of ptfe tape on the threads. check the banjos are tight. Also check they are not too long. Many are.............
they tighten up, but are bottoming not sealing on the washers.
Bleed them up as normal but don't forget to bleed the m/c to.
tie the lever over night if required.
There's no rebuild kit for the road equipment i'm afraid.