By the time the first ten 7-car sets had been delivered, it was found that the buffing plates between carriages would bind when going around tight curves or through complicated pointwork, so this equipment was removed in time for delivery of the 11th train.
Around the same time, the Victorian Railways was experimenting with replacing cast-iron brake blocks with a non-metallic compound (probably asbestos), so Set 11 was fitted with these, and tested between Seaford and Frankston, in 5 mph increments up to line speed, in both directions.