Devbliss Technical Advice - Fan or Piston?

[stuwaudby]

Ok, Jack the Oxycon failed a few weeks ago. I stripped him down, put him back together and magically he worked again. Last night I had a good boro session (about an hour) and he suddenly stopped again. When i switch him back on the motor judders every second. I suspect it one of two things:

1. The cooling fan in the base has failed. (Causing an overheat cut out.)
2. The PTFE piston ring on one of the pistons is worn over about an inch. (Causing the piston to jam.)

Anyone had similar?

[stuwaudby]

New fan and motor supressor going in tonight.