Getting broken fuel pump bolt out

[madoc1]

great. thx. guys, now i get the idea. don't need it now, but you never can tell.

[mandoman]

Yep, transfer punches.... only thing is the clearance, I would wrap the bolts with cellophane tape till they fit snugly in the housing, leaving enough exposed to screw into the tapped holes there can be as much as .025 clearance on the cover plate..... it's just the formula... tapped hole drill size is a % over the actual diameter of the minimum thread root so the tap doesn't break. screw is usually rolled with a screw machine, produces a slightly smaller outside dia. Thru holes are usually .016 to .032 oversize the nominal screw size.... such is standard practice.. if you add the oh f#%$ factor in and you don't or cannot put your piece on a drill press and you factor in the mechanics of a hand drill............... go slow and think a lot. But Yes if you compensate for all the variables a transfer punch will allow you to get very close to the C/L but in my experience it is usually best to use the champher existing in the hole that the broken stud is in... just eliminates variables

[mandoman]

I might add just one more thing. before you go thru all this process try the simple stuff first. I would be surprized to know the actual number of bolts I have removed with either a scribe or a punch. Sometimes you can get a scribe and just spin out the stud. If the stud is big enough you can use a center punch and a hammer, the trick is not to hit the threads on the tapped hole or not to mushroom the stud and make it expand in the tapped hole if you do you will be drilling. One good jarring lick with a punch and a hammer can exert as much force as snugging up a screw with a wrench. God Bless

[crash12888]

All true, that's why back in post 5 I asked how it broke off, over tighten or bottom out and broke off.
I've done some work in punch and forming dies and they can be quite tight and know all about the small punch or scribe trick.
Sometimes ya get lucky, sometimes you're in for a long night!

[mandoman]

so true so true,