8v71 fuel pump

[gus]

I prime with an electric pump at the tank. I do this because if there is a leak in the supply line fuel will flow from the hole and I can find it. When you suck from the engine side a fuel line hole takes in air with the engine operating and may or may not leak fuel when not operating.

Priming from the tank also shows any leaks in the primary filter, anything up to the mechanical fuel pump.

Since the bus mechanical pump is a sucker I see no possible way to damage those seals with a low pressure electric pump. It is made for autos with carbs which use very low pressures.

There is no difference to a pump intake between suction and pressure, it is all just difference in pressure anyway.

Suction and pressure, pressure and suction - same ole samo. Suction is indirect pressure.