D21 Leaking gas from return fuel line at fuel tank.

[hanginmoss]

I have a 1990 D21 leaking fuel from the return fuel line at the fuel tank/fuel pump. We have replaced the fuel pump because it went out and both rubber fuel lines at the tank. Now we have the leak at the return fuel line. It is under pressure when the truck is shut off. Anyone have any ideas?

[whomadewho]

First thing I would do is match the vin number with the part number. POSSIBLE you installed the wrong pump. Several different pumps were used depending where the truck was manufactured? There is also a high pressure pump that was used in 86- 95 pickups. You didn't say if the pump is - used - new - aftermarket - Possible defective pump?

[hanginmoss]

The pump is new and was purchased from Advanced Auto Parts.

[whomadewho]

Still need to check the vin number and the part number. If you didn't have the issue in the past & after changing the pump you do the chances are good the pump is the wrong application. Chances are it's not something that occurred during the installation. You could put compressed air in the filler neck,this would check the lines for leaks. Don't get carried away with the air pressure. The only other thing that comes to mind is the particles in the canister have migrated into the lines and it's possible the system is plugged. The newer hard body's not sure about 1990 have a solenoid located on the passenger side on the frame behind the rear tire that goes to the canister it's possible the plug got disconnected when R&R of the tank. Again may not apply to the 1990. You could contact a Nissan dealer,give him the vin number and you can get The original factory part number which will allow you to cross references the part number.

[hanginmoss]

Thanks. We will get the VIN and cross reference the part numbers and look for the canister and solenoid.