I had the same problem, if you find the lever spongey or more oil behind the pads, then its definitely one of the seals in the slave cylinders. If this is the case then your best bet is to get in touch with Hope as it will probably need to be sent away, their customer service is excellent, so dont worry. Also make sure that u decontaminate your rotor and pads. Do this by pouring boiling water on your rotor and scrubbing it with fairy liquid with a toothbrush and rinse again with hot water. Then burn any oil that remains on your pads with a blowtorch, just dont heat them intensely. The brake may need to bed in again, so give it time, putting water on the rotor, then riding, giving it short sharp bursts of brake down a hill usually works. Hope this helps (excuse the pun) Andrew