Category Archives: Cummins 4BT

Cummins 4BT – Piston and Connecting Rod – Assembly

Be sure “ fro nt” marking on piston and the numbers on the connecting rod and cap are oriented as illustrated. Install the retaining ring in the pin groove on the ‘front” side of the piston. Lubricate the pin and pin bores with engine lubricating oil. Install the pin. Pistons do not require heating to… Read More »

Cummins 4BT – Piston Inspection

Inspect the piston for damage and excessive wear. Check the top, ring, grooves, skirt and pin bore. NOTE: If severe piston damage has occurred, check the turbocharger and other exhaust components for damage from debris. Measure the piston skirt diameter as illustrated. Use a new piston ring to measure the clearance in the ring groove.… Read More »

Cummins 4BT – Piston, Pin and Connecting Rod – Cleaning

Caution: Do not use the bead blast method to clean the piston. The piston will be damaged by blast material embedded in the aluminum. Soak the pistons in cold parts cleaner. Soaking the pistons overnight will usually loosen the car­bon deposits. Caution: Do not clean the pistons and rods in an acid tank. Wash the… Read More »

Cummins 4BT – Piston and Connecting Rod Assemblies – Removal

Mark each connecting rod cap according to cylinder. Rotate the crankshaft until the pistons are below the car­bon deposits which are found above the ring travel area. Use a scraper or a blunt edged instrument to loosen the carbon deposits. Do not damage the cylinder with the scraper. Remove the remaining carbon with a Scotch-Brite®… Read More »

Cummins 4BT – Piston and Rings – Replacement

Preparatory Steps: • Drain the coolant. • Remove the cylinder head. Refer to Procedure (7-07). 17 mm Drain the lubricating oil. After lubricating oil is drained, install the drain plug and a new sealing washer. Torque Value: 80 N»m [60 ft-lb] Remove the dipstick bayonet. 10 mm Remove the lubricating oil pan.  

Cummins 4BT – Drive Belt – Installation

3/8 Inch Square Drive Lift the tensioner and install the belt. Service Tip: If difficulty is experienced installing the drive belt (the belt seems too short), position the belt over the grooved pulleys first and then while holding the tensioner up, slide the belt over the water pump pulley.

Cummins 4BT – Alternator – Installation

10 mm Assemble the alternator bracket to the thermostat hous­ing. Torque Value: 24 N»m [18 ft-lb] Check the alternator pulley visually or with a straight edge to make sure it is aligned with the other pulleys and is parallel to the front face of the block. Tighten all capscrews in the following sequence: 1. Alternator-to-alternator… Read More »