Fuel pumps leaking

Has anyone used 044 pumps?

Mine are leaking from the outlet. Should I be using an o-ring, crush washer or both? plus sealant?

Ive read contradicting things online, so thought Id ask

Crush washer only. It's a metric thread not ORB so no O.ring

You should also be using a check valve on the outlet of each pump as there is no internal one. If you stage the pumps fuel will flow backwards through the 2ND pump without a check valve.

Thanks mate.

So originally I used crush washers, so I thought id replace them, still leaked.

Tried different OD crush washers and still leaked.

Used 2 washers per fitting and think its solved the problem.

Pretty much high on petrol fumes after that