Mike you can use stuff called Loctite 515 flange sealant
or Loctite hydraulic pipe sealant
. Just smear it all over the olives, do up the fitting, wait 20 mins then run test. I used it on my leaking Cav primary filter & fixed it no worries but I do have flexible fuel
lines ( Yanmar
engine) which of course dont get affected by vibration as a solid ones do. Agree with other posts you dont want thread tape in your pump. I use it on the positive pressure side of the lift
pump but I have the ability to strip & clean injection pump if required ( hasnt been a problem so far). I only wrap it around the olives & dont put it on the thread. Much less risk for you financialy as mentioned in other post to buy another fuel line or use Loctite if you decide against a new filter assembly. Actually like my CAV filter as you can buy cheap
filters for them anywhere. Let us know how you get on.