As the loco passed the Caledonian bridge, the radius rod on the left side started to jump and bend due to a seized valve.  The loco was immediately halted.  The rod to the valves on the left side were removed, inspection ports opened for steam relief, and then T369 hauled R711 back to Ballarat East Shops.   R711 is seen here with T369 waiting while it is prepared for the run back to Ballarat East Shops.

As each piston has 8 rings instead of other R class 2, this makes for a very steam-tight piston, but the calculation of differing expansion rates between bronze piston ring and steel liner involves some trial and error.   Machining was carried out overnight.