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Extracting or installing wet cylinder liners on Cummins NT (855) or N14 5.5-inch bore commercial diesel engines? Attempting to pull cylinder liners using slide hammers, weld beads, or pry bars—or driving new liners into block bores using sledges and wooden blocks—causes catastrophic engine overhaul failures. Cummins NT and N14 engine blocks feature 5.5" bore wet liners with precision lower O-ring sealing grooves and upper counterbore ledges. Applying uncentered, eccentric extraction forces cocks the liner, scoring internal block lands and ruining O-ring sealing surfaces. Conversely, driving new liners down with impact blows pinches, twists, or cuts lower coolant O-rings, leading to immediate coolant contamination in crankcase oil. Furthermore, unlevel liner seating causes uneven liner protrusion, destroying head gasket fire ring crush and resulting in premature combustion blow-by. Engineered for professional commercial diesel mechanics, Cummins dealership rebuild stalls, and heavy machine shops, the M20105 Cummins NT / N14 Liner Puller & Press Combo provides a 24.00-pound dual-function mechanical extraction and installation system—delivering 100% continuous, axial force to remove stuck liners cleanly and press new 5.5" liners into place with perfect O-ring integrity and uniform protrusion.

The Critical Physics of Dual-Function Axial Alignment & O-Ring Preservation

On Cummins 855 NT and N14 engines, cylinder liners maintain tight interference fits inside lower block bore lands while relying on rubber Crevice Seals and D-rings to separate engine coolant from oil sumps. Over hundreds of thousands of miles, scale rust and carbon pack tightly into lower land gaps, locking wet liners in place. Removing a stuck 5.5" liner requires pure axial lifting force directly along the cylinder centerline. The M20105 Liner Puller engages the bottom edge of the 5.5" liner smoothly, using a heavy-duty mechanical forcing screw to break rust bonds without tilting the liner or gouging cast-iron block lands. Once the block is cleaned and prepared, the M20105 converts seamlessly into a precision liner press. A ground press plate sits over the top rim of the new liner, distributing forcing screw load across 360 degrees. As the technician turns the forcing screw, the liner slides smoothly down past lower block chamfers, compressing coolant O-rings evenly without shear or pinch damage until the upper flange seats squarely on the counterbore.

• Targeted Cummins 5.5" Bore Platform Coverage – Purpose-built specifically for 5.5-inch bore wet cylinder liners on Cummins NT (855) and N14 diesel engines.
• 2-in-1 Dual-Function Puller & Press System – Performs complete cylinder liner removal and press installation using a single integrated tool kit.
• Protects Lower O-Rings & Block Bore Lands – Eliminates impact shocks and cocked insertion angles that slice lower coolant seals or score cast-iron block bores.
• Ensures Uniform Liner Protrusion & Seating – Presses liner flanges dead-flat onto block counterbores to maintain exact factory protrusion for total head gasket fire ring crush.
• Substantial 24.00 lbs Heavy-Duty Shop Construction – Manufactured from high-tensile structural alloy steel designed for continuous daily use in engine rebuild stalls.

Stop Pinching O-Rings. Command Total Cummins NT & N14 Engine Rebuilding Precision.

The M20105 Cummins NT / N14 Liner Puller & Press Combo – Cylinder Liner Service Tool is an essential capital asset for commercial truck repair centers, Cummins dealership rebuild stalls, fleet maintenance facilities, and heavy diesel machine shops. Prevent sliced O-rings, extract stuck liners safely, and rebuild Cummins 5.5" bore engines with complete mechanical authority using Apex tools.

Technical Specifications

Technical Metric	Value / Fitment Reference Guidelines
Target Engine Platforms	Cummins NT Series (Small Cam, Big Cam 855) and N14 Commercial Engines
Cylinder Bore Size Capacity	5.5-Inch (5.5") Bore Diameter Wet Cylinder Liners ONLY
Primary Operational Functions	Dual-Function Mechanical Cylinder Liner Extraction (Puller) and Press Installation (Press)
Part / Model Reference Number	M20105 (M 20105 / 20105)
Construction Metallurgy	High-tensile heat-treated structural alloy steel with heavy forcing screw assembly
Service Environment Suitability	In-Frame Fleet Maintenance Overhauls & Out-of-Frame Machine Shop Rebuilds
Total Package Shipping Weight	24.00 lbs (Heavy-duty master commercial shop liner combo system)

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