the best and longest life lubricant i have found is the dow corning 111 o-ring and valve lubricant.... it is a very heavy/thick waterproof silicone grease that stays put and wont wash off....
being a silicone formulation, its very slippery and allows the pump to work like new for a long time.
as some have said, they get several years out of their systems before needing repair, but as with ANY lubricant that remains on the item for a few years, the grease WILL collect bits of debris from the water as it passes thru the system, so regular maintenance every couple hundred flushes to refresh the grease will insure you dont have a "break down" unexpectedly....
flushing oil thru the system is only a temporary short term "symptom reliever"... but doesnt "fix" the problem.
being a silicone formulation, its very slippery and allows the pump to work like new for a long time.
as some have said, they get several years out of their systems before needing repair, but as with ANY lubricant that remains on the item for a few years, the grease WILL collect bits of debris from the water as it passes thru the system, so regular maintenance every couple hundred flushes to refresh the grease will insure you dont have a "break down" unexpectedly....
flushing oil thru the system is only a temporary short term "symptom reliever"... but doesnt "fix" the problem.