05-09-2017 09:38 AM
PLEASE CHECK THE STRAINER BEFORE THE RAW WATER PUMP N THE VALVE OPENING LEVER SOMETIMES I LOOKS OPEN FULLY BUT THE FLAP IS HALF OPEN THIRDLY CHECK THE PUMP IMPELLER
05-08-2017 08:28 PM
I work on a tug that was re powered in 1991 with a 3508. Since then it has always had a problem sucking air in the water pump when backing hard. The engine must be shut down to bleed the air out. The sea chest is well below the water, as is the prop.
3" piping and valve at the sea chest.
Any ideas? I am hoping a pump rebuild or changing to a different style pump will help.