Direct start Pre-cup with broken glow-plugs

[Dunefanatic]

Well I need some advice from experienced folks on the on the topic of a Direct start D2 Pre-cup with broken glow-plug. I have two pre-cups out of my D2 that a friend is fixing all kinds wrongs and making them right but he has two pre-cups with glow-plugs broken down half way in.

I have heard about drilling out glow-plugs but have been warned they are a tight fit and hard steel so if a drill bit breaks I am SOL.

I have also been told could try drilling blindly a pilot hole from the combustion side of the pre-cup into the glow-plug cavity to tap glow-plugs out with a punch and then need to plug or weld up hole.

Looking for any guranteed ideas that are known to work. Should there be somebody on the west coast (SF Bay area proximity preferrred) who has experience in rremoving these stuck little devils and they are open to working on mine, email me.

Words of advice all appreciated.

Greg

[WyoCat]

Greg,
Just a claification question. The glow plugs have been removed or unthreaded and a piece of the tip is broke off and is in the pre-cup...Correct?

[Dunefanatic]

You got it Chad. Two glow plugs broken half of each still in the pre-cup.

[Old Magnet]

Hi Greg,
No, never had the pleasure of that little task.......but all may not be lost if attempts go south.
There is a fellow in King City that was known to be taking the D4 glow-plug chambers and rethreading the nose to fit the late D2's. Haven't had contact with him for awhile but can look up the contact info if you need it.

[Dunefanatic]

Pete,

Don mentioned to me his name (which I forget at the moment) but please private mail his contact info if you can locate and I will contact him upon my return from some work travels.

Would you like to take a swag at the wonders of glow-plug removal?

Greg

[Old Magnet]

Did see one of those come apart. The pre-com chamber is two machined halves that are "furnace brazed" together (I believe). Don't know if you could get one apart and back together or not. It would let you press the element out. Think you'd snag and break even the hard carbide tool steel bits and the 1/4 in. size doesn't give you much to work with. Think I'll pass on that one
I'll dig up the contact information.

Those D2 glow-plug chambers are rare as hens teeth but you might get lucky if you go shopping.

[Old Magnet]

Greg,
Check with Don, he has the contact information for Niel in King City.

[Dunefanatic]

Thanks Pete. Will be back in the states in a week and will hook up with Don.

[edb]

Hi Greg,
if you can chase down someone with a "spark eroder" they do a terrific job of eating up/out broken maniflold studs, turbo housing bolts, etc. so it should work great on one of those. We had one at the Dealer and used it for any hard metal, ie, drills, taps, easy outs, dowel pins or what ever.
Cheers,
Eddie B.

[ccjersey]

sounds like Electrostatic Discharge Machining. I have just heard of it, never seen it done.

Does it tend to stay off the surrounding metal while you remove a broken bolt etc? or is that all in the skill of the operator?