Fuel line

Ok didn't they put any fuel in the filters before they put them on?

 

Fill filter with fuel. Let it soak and fill to top again

 

That valve is a one-way check valve. If you install it as close to the filters on the line that runs up to the engine that will hold the prime. Just fill the filters and put them on and you're ready.

You can buy them at any plumbing supply and they're very inexpensive.

 

I much rather use gasoline as a starting aid for any diesel engine.

 

Um no, it’s a valve you turn off before you pull the filter