I replaced my injector pump about 2yrs ago on my '92 D-350 and everythings been fine until yesterday. I felt a vibration in the pedal ,check it out and two of the three studs had back out and the third was loose. I replace the missing ones and tighten them all , but one felt like it was close to stripping. this morning on the way to work I felt the vibration again,all three were loose again. My question is are the studs size 5/16 and does anyone have any suggestions. Thanks

 

locktite. not the permanant kind.

 

The studs are metric.