Cummins ISX15/QSX15 SOHC Casting Repair Kit

The Cummins SOHC Injector Seat Casting Repair Kit (PN: 450-6117-60) from Irontite is designed to repair cracked injector seat areas in Cummins SOHC cylinder heads. The kit utilizes a machining operation to remove cracked, fatigued material in the injector area and replaces it with fresh, new metal. The kit includes a cast ductile iron taper threaded “J” plug designed to absorb casting cracks. Component items to complete tooling needs are available.

The Cummins SOHC Injector Seat Casting Repair Kit (PN: 450-6117-60) is a comprehensive solution for repairing cracked injector seat areas in Cummins ISX15 / QSX15 SOHC cylinder heads. This field-tested kit is designed to help machinists address the increasing scarcity of usable cylinder head cores by providing the tools and components necessary to repair damaged injector seats.

Kit Components:

• Enlarging Counter Bore Cutter (434-6513-20)
• ⅞ Split Sleeve Tap Driver #3MT (449-6933-30)
• J-Tapered Reamer (407-5213-10)
• J-Tapered Tap (407-5313-10)
• Drill Bushing (414-6157-19)
• M12.8 Taper Length Drill (414-6157-26)
• End Facing Counter Bore Cutter (416-6156-61)
• Guide Bushing (416-6156-32)
• Driving Arbor (414-6114-10)
• ISX / QSX Casting Seat Cutter (414-6157-28)
• Casting Seat Cutter Gauge (414-6157-29)
• Gauge Handle (414-6111-30)
• Gauge Finger (433-6991-00)
• J-Solid Diesel Iron Plug (6) (452-2613-13)
• Tool Box with Tray (467-1950-50)
• Counter Bore Pilot (2) (416-6117-62)

Consumables (Not Included):

• SOHC Injector Sleeve Assembly (419-6197-05)
• Ceramic Seal (pint) (468-9120-16)
• Tap-O (8 oz) (468-9920-08)

Repair Process:

1. Remove Old Injector Sleeves: Use a Cummins sleeve remover to remove the old injector sleeve from the injector holes in the casting.
2. Clean Injector Seat: Clean the seats at the bottom of the injector holes using the casting seat cutter (414-6157-28), driving arbor (414-6114-10), and guide bushing (416-6156-32)This will remove accumulations and corrosion, especially in the 90-degree area at the nose of the casting seat.
3. Preliminary Check: Inspect for small cracks on the face of the head at the injector hole area. Mark any collateral cracks that extend beyond the area to be covered by the replacement plug for later repair with Irontite A-200 or A-235 Plugs. It may be desirable to drill a hole at the end of the collateral crack to relieve casting stress.
4. Enlarge Injector Hole: Use the enlarging counterbore (434-6513-20) with the pilot (416-6117-62) to cut out the injector area of the casting from the face side of the cylinder head.
5. Ream Injector Hole: Ream out the injector hole using the reamer (407-5213-10) and driver (449-6933-30) at 60-80 RPM. Lubricate with Irontite Tap-O (468-9920-08). Ream only enough to start the tap.
6. Tap Injector Hole: Tap the reamed hole using the tap (407-5213-10) for the “J” Plug installation. Keep the tap well-lubricated with Irontite Tap-O (468-9920-08).
7. Install and Drill Replacement Plug: Clean the tapped casting area and the “J” tapered plug. Apply Ceramic seal (468-9120-16) on the casting area and the plug’s threads. Thread the plug into the casting and torque to 200 ft-lbs. Turn the casting over and, from the spring side, drill through the plug using the taper length drill (414-6157-26) and drill bushing (414-6157-19).
8. Face Off and Peen Outer End of Plug: Turn the casting back over and face off the outer end of the replacement plug using the end-facing counterbore (416-6156-61) and pilot (416-6117-62). Bring it down to about 1/16” above the face of the casting. Peen the outer rim of the plug, working away from the center. Smooth the end of the plug.
9. Check for Collateral Cracks: Check for any small cracks extending beyond the plug’s perimeter and repair them using the Irontite crack repair process.
10. Cut New Injector Seat: Cut a new injector seat using the casting seat cutter (414-6157-28), driving arbor (414-6114-10), and guide bushing (416-6156-32). Use the gauge finger (433-6991-00) and casting seat cutter gauge (414-6157-29) to ensure correct depth. Operate the seat cutter at 60-80 RPM and lubricate with Irontite Tap-O (468-9920-08).

Note: Valve seats do not need to be removed unless cracks extend to the valve seat area