Engine - Cylinder Head Bolt/Main Bolt Extraction
TSB # IB07-01-S001Issue Date: MAY 2007
Subject:
Information On Use Of Kent Moore Bolt Extractor Tool Kit EN-47702 For Removing Broken Cylinder Head Or Main Bearing Cap Bolts On Inline Engines
(This Bulletin Supercedes IB05-01-S007)
Affected Vehicles:
2003-2008 Isuzu Ascender
2007-2008 Isuzu i-290/i-370 (TI)
2006 Isuzu i-280/i-350 (TI)
Service Information
This bulletin is being revised to update models model years and Service Information.
A Torque to Yield (TTY) bolt like a cylinder head bolt or main bearing cap bolt may break during repair procedures. Interaction between a TTY bolt and threads may cause the bolt to bind or break upon removal. Kent Moore EN-47702 Broken Bolt Extractor Kit is now classified as an essential tool.
Prior to removing the cylinder head or main cap bolts perform the following procedure:
^ Using an appropriately sized punch and hammer tap on the head of each bolt. The vibration produced by this procedure will assist in successful removal.
^ If a head or main bolt breaks during engine disassembly use a Kent Moore EN-47702 broken bolt extractor kit. The Kent Moore EN-47702 broken bolt extractor kit has been released to assist in removal of the remaining bolt segment(s). Many times the remaining bolt segment will back out easily with a pick tool or a reverse twist drill bit.
IMPORTANT:
Drill bit EN-47702-6 is a 5/32" reverse twist and needs to be used with the drill motor in the reverse direction.
IMPORTANT:
Never reuse main bearing or cylinder head bolts. Always make sure that the engine block threaded holes are clean and do not place oil or threadlocker on the bolts.
Utilize a thread chase tool followed by cleaning with dry compressed air to insure threads are clean and dry prior to installation of new TTY bolts. Bolts that creak and snap while tightening will fail due to excessive torque caused by threads contaminated with debris antifreeze or oil. Trace amounts of oil or antifreeze will cause this condition. In extreme cases the threads may need additional cleaning with a non-residue cleaner like a brake clean product followed by drying with clean & dry compressed air.
NOTE:
Failure to use essential Kent Moore tool EN-47702 Broken Bolt Extractor Kit for engines that have broken head or main bolts may affect warranty claim approval.
Kent Moore EN-47702 Bolt Extractor Tool Kit.
The Kent Moore bolt extractor kit EN-47702 provides the following components to assist in removal of the broken bolt segment:
1. One 5/32" reverse twist drill Kent Moore EN-47702-6.
2. One double-ended drill pilot insert Kent Moore EN-47702-1 ensures a straight drilling procedure.
3. Drill pilot inserts for larger diameters head or main cap bolts Kent Moore EN-47702-2 ensure a straight drilling procedure.
4. Bolt extraction # 3 EZ Out Kent Moore EN-47702-3 after the drilling procedure.
5. Bottom tap (M11 x 2) Kent Moore EN-47702-5 for the head bolts to chase the threads after the completion of bolt removal.
6. Bottom tap (M10 x 1.5) Kent Moore EN-47702-4 for the main bolts to chase the threads after the completion of bolt removal.
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