Well the four I pulled that were hard to get out were, I am sure stuck with carbon from the GP tip to the sides of the prechamber. I believe you want it slightly bigger than the tip and as I said 19/64 " was the biggest that easily carved off the carbon, and 5/16 would have carved off more than carbon. It's not hard to do.

__________________
Thanx,
Alberta Luthier
1983 300CD ('Stinky')155k miles, 2.47 diff, EGR removed, AAZ injectors with 265 nozzles from Sean,and vogtland lowering springs.
1984 300SD ('Old Blue')150k Klicks from Japan originally, came with rear head rests, no sunroof and never had an EGR

If the bore brush is big enough to do the job, it will be too big to insert. twist and then pull out again without breaking it off in the GP hole. You probably do not have a plan B for removing the bore brush fragment from the hole, do you?

You hurt my feelings...... Not at all.....you need to feel comfortable with the tool and procedure. I have never encountered much carbon in the prechamber that would have shortened out the electrode or caused the engine to suffer. From my experience it is the fine carbon build up around the shank that prevents the glow plug from turning. The fine carbon cake around the glow plug shank wedges it in place and creates so much resistance that you can shear the head right off with to much force. Until you clean the carbon from the port you will encounter a lot of resistance even trying to put in the new glow plug with anti-sieze on the threads. Its not the thread or electrode that gets stuck as much as the shank being "cemented" in with carbon.

May be someone else can pipe in with their multiple diesel vehicle experiences

__________________
FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K

Thanks for the advice. But still...can someone measure the width of an actual GP reamer.

__________________
'85 300td Frybrid WVO Kit

I don't have a micrometer or I would. Where in NW Indiana are you located?

John

__________________
Certified Registered Nurse Anesthetist (CRNA)
2002 F250 powerstroke with Plantdrive WVO conversion
1983 300SD 190K miles ,sold
2006 E320 CDI

I'm on South Bend, but I spend my summers in northern WI (land o lakes) in your neck of the woods.

__________________
'85 300td Frybrid WVO Kit

GP reamer is .281 inch, or 7.08 mm.
GP measures .239 inch, or 6.10 mm.

__________________
83 SD

84 CD

Thanks a lot ToomanyMBZ. I don't think I'm interested in renting your GP reamer anymore...thanks for giving me the info rather than holding out so I would have to rent one from you. You and so many others on this forum are A+ individuals.

__________________
'85 300td Frybrid WVO Kit

and the 19/64ths drill bit is .296875 , slightly bigger than the reamer.
I really don't think it would be good try the 5/16s though

__________________
Thanx,
Alberta Luthier
1983 300CD ('Stinky')155k miles, 2.47 diff, EGR removed, AAZ injectors with 265 nozzles from Sean,and vogtland lowering springs.
1984 300SD ('Old Blue')150k Klicks from Japan originally, came with rear head rests, no sunroof and never had an EGR

No prob, folks are here to help. The brush is for use after, then vacuum out any debris.

Attached Thumbnails

   

__________________
83 SD

84 CD

After cleaning...all GPs out...will turning engine over a few times blow prechamber out enough?

Or is a shopvac with a small nozzle better?

__________________
1983 300SD 307k miles
1993 Ford Escort Wagon 215k miles
1995 Isuzu P'up 214k miles