Fuel pump noise 740 Volvo

[not hereplease]

I have a noise with the fuel pump under the floor.
I understand that the problem could be the pump or also the fuel pump in the tank.

I am thinking of getting both pumps from a breaker but don't want to change anything I don't need to.

What would be the best an easiest to change first the fuel pump under the floor or in the tank

 

[not hereplease]

What I forgot to mention was, if I replace the fuel tank pump and the noise goes away then do I assume everything is O.K with the fuel pump under the floor, or would you do it the other way first by changing the pump under the floor.

 

[Rod Gray]

There is a bellows hose on the pump in the tank. The noise in the main pump is usually air in the system caused by the hose rotting. That's your cheapest part so start there. If not that, make sure you have voltage to the tank pump.