Journal Update

April 2020
Before You Remove Your Old Fuel Pump

Before removing your old fuel pump, make sure you have ALL the parts you need to fit the new one. The size of the inlet and outlet fittings on the Carter and Airtex fuel pumps varies a lot — I had three fuel pumps and none of them used the same size fittings. Don't assume (as I did) that the new fuel pump will be able to use your existing fittings. I discovered this the hard way when I had already fitted the new pump only to discover I didn't have the correct outlet fitting.

Common automotive pipe fittings include AN, UNF, NPT and BSP.

  • AN and UNF fittings use SAE (parallel) threads.
  • NPT fittings have tapered (conical) threads and seal by an interference fit at the threads. They require a thread sealant.
  • BSP fittings have straight (parallel) threads.

Also be very careful with fuel lines with flared ends. The fitting that they screw in to must be designed to accept a flared end to create a seal, otherwise when you start the engine fuel is going to squirt out all over your engine bay (ask me how I know this).