Head Bolt Torque
Verified Factory Specs
Heavy Commercial Diesel Cylinder Head Bolt Torque & Sequence Directory
Factory OEM cylinder head bolt torque specifications, torque-to-yield angle degree sequences, and tightening patterns for Cummins ISX15, Detroit DD15/DD13, Cat C15, and PACCAR MX-13 commercial diesel engines.
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Total Cylinder Head Bolts: 38 Bolts (M16 x 2.0 / M12)
Official Factory Tightening Pattern
Center-outward spiral crisscross (Cylinder 3/4 outwards to 1/6)
Step-by-Step Torquing Stages (Follow in Numbered Sequence)
1
Stage 1
Torque all main bolts to 150 ft-lbs (203 N·m)
2
Stage 2
Torque all main bolts to 220 ft-lbs (300 N·m)
3
Stage 3
Rotate all main bolts an additional 90 degrees clockwise (Torque Angle)
4
Stage 4
Rotate all main bolts an additional 90 degrees clockwise (Final Turn: 180° total)
5
Stage 5
Torque the 6 small perimeter M12 bolts to 40 ft-lbs (54 N·m)
⚠️ Master Technician Tip: Clean and blow out all cylinder block bolt blind holes with compressed air. Lightly lubricate bolt threads and under-head flanges with clean engine oil before installation.
OEM Specification Source: Cummins QuickServe Online Service Manual Bulletin 003-004 (ISX/X15 Overhead Set)
Master Heavy Diesel Head Bolt Torque Summary Table
| Engine | Bolt Count | Thread Size | Initial Torque | Final Angle Stage | Step-by-Step |
|---|---|---|---|---|---|
| Cummins ISX15 / X15 | 38 Bolts | M16 x 2.0 / M12 | Torque all main bolts to 150 ft-lbs (203 N·m) | Torque the 6 small perimeter M12 bolts to 40 ft-lbs (54 N·m) | View Sequence → |
| Detroit Diesel DD15 (GHG14 / GHG17 / Gen 5) | 38 Bolts | M15 x 2.0 | Torque all bolts to 74 ft-lbs (100 N·m) in numbered order | Turn all bolts an additional 90 degrees clockwise (Torque Angle 2) | View Sequence → |
| Caterpillar C15 & C15 ACERT (6NZ / BXS / MXS) | 26 Bolts | 3/4-16 Grade 8 | Torque bolts 1 through 26 to 200 lb-ft (270 N·m) | Turn bolts 1 through 26 an additional 90 degrees clockwise (Torque Angle) | View Sequence → |
| PACCAR MX-13 (EPA10 / EPA13 / EPA17 / EPA21) | 38 Bolts | M15 Torque-to-Yield | Torque all bolts to 75 ft-lbs (102 N·m) | Rotate all bolts an additional 90 degrees clockwise (Final 180° turn) | View Sequence → |
| Detroit Diesel DD13 | 38 Bolts | M15 x 2.0 | Torque all bolts to 74 ft-lbs (100 N·m) | Turn all bolts an additional 90 degrees clockwise (Torque Angle 2) | View Sequence → |
| Caterpillar 3406E (5EK / 2WS / 1MM) | 26 Bolts | 3/4-16 Grade 8 | Torque bolts 1 through 26 to 200 lb-ft (270 N·m) | Turn bolts 1 through 26 an additional 90 degrees clockwise (Torque Angle) | View Sequence → |
| Detroit Diesel DD16 (Heavy Haul 600 HP) | 38 Bolts | M15 x 2.0 | Torque all bolts to 74 ft-lbs (100 N·m) | Turn all bolts an additional 90 degrees clockwise (Torque Angle 2) | View Sequence → |
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Related Heavy Diesel Engineering Tools
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Technical Reference Citation: Cummins, Detroit Diesel, Caterpillar, PACCAR OEM Engine Assembly Standards