Bafanguy,
Itīs been a while but MDC had the pump casing modified as I recall.
The condition didnīt occur with a straight loss of fluid but only when there was a crack in the casing of the pump. (Of course the pump normally wonīt run unless there is a pressure drop on on side and a crack in the casing tended to create a very sudden loss.) Could well be that the system on the good side recovers when the cut off level is reached- but the incident may have happened by then.
A similar pump was used by the way on the DC-10 between the systems, where it was called the motor pump - typical Douglas - a new name for an old system every model.
I once had access to all the literature on this but am working from memory now.
All the best,
FC.