Aaaargh I'm going mad! I managed to replace the accumulator and the test drive went nicely. However, today after about 50 km of driving the exact same problem occurred: selespeed warning light flashing and the car won't change gear. After a few seconds, the problem disappears and selespeed works for a brief moment. Again, I noticed oil leaking on to the ground. I topped up the slespeed oil and the car drove fine, so that seems to be the reason. Any pointers? I'm getting really desperate?