The PBL pumps on the Weekend Warriors had major issues with this. I have to change them once every year or two. It was easy on these as four bolts on side of pump to access the gears. Has another smaller door also with four bolts to access the screen filter on the same cover as these four larger bolts). You can go to a local pump store and they sell the gear kits. The gears just pull off the shaft (one is indexed with a small rectangular plastic insert) and there is also an o-ring for the cover to replace that is included. Just a little fuel comes out the pump when opening it up on these.
Would see if yours is similar or perhaps even the same pump. I know the gear kit is Graco part 260277 on mine.