Washing machine (Bosch Exxcel WFX2868, 7 years old) is tripping the RCD after a few minutes - some time after the motor starts up. Once it has tripped once, it will trip again immediately if you turn it on, but the short eventually clears. If you switch it to the drain cycle, it will turn on and drain just fine.
There's about 2cm left on the brushes, and they seem to be contacting fine (measured 2.4 ohms between brushes, no idea what the nominally correct value is though). I measured all terminals on the motor against earth and got no hint of a short.
Any ideas?