Category Archives: Cummins 4BT

Cummins 4BT – Thermostat – Installation

Position the thermostat as shown in the illustration. “ Package” the lifting bracket and thermostat gasket to the thermostat and thermostat housing. Make sure the gasket is aligned with the capscrew holes. Install the capscrews and use your fingers to tighten. The notched end of the rubber thermostat seal points away from the cylinder head.… Read More »

Cummins 4BT – Cylinder Head – Installation

Position the cylinder head gasket over the dowels. Carefully put the cylinder head on the cylinder block and seat it onto the dowels. Cylinder Head Weight: 4 Cylinder – 36 Kg [80 lb] 6 Cylinder – 51.3 Kg [114 lb] Push Rods – Installation Position the push rods into the valve tappets. Lubricate the push… Read More »

Cummins 4BT – Cylinder Head – Assembly

NOTE: Clean all cylinder head components before assembling. Install the valve stem seals. The intake and exhaust seals are the same. Valve Spring Compressor Compress the valve spring after assembling the spring and retainer. Install new valve collets and release the spring tension. After assembly, hit the valve stems with a plastic hammer to make… Read More »

Cummins 4BT – Valve Spring Inspection

Inspect the valve springs. Measure the valve spring. A load of 289.13 to 321.16 N. [65.0 to 72.2 lb] (1991) and 359 to 397 N. [80.7 to 89.2 lb] (1994) is required to com­ press the spring to a height of 49.25 mm [1.94 in].  

Cummins 4BT – Cylinder Head Cracks – Reuse Guidelines

These guidelines apply only to cracks extending from the injector bore to the intake valve seats. Replace cylinder heads which exhibit valve bridge cracks in any other location. The reuse guidelines for a cylinder head with a crack extending from the injector bore to the intake valve seat are as follows: If the crack does… Read More »

Cummins 4BT – Valve Seat Inspection

Inspect the valve seats for cracks or burned spots. Refer to the following reuse guidelines for any cracks discovered. Service valve seats are available for seats with burned spots that will require more than 0.254 mm [0.010 in] grinding to clean up. Refer to the Alternative Repair Manual, Bulletin No. 3810234, for valve seat in­… Read More »

Cummins 4BT – Cylinder Head Deck Inspection

Use a straight edge and feeler gauge to measure the overall flatness of the cylinder head deck. The overall flatness, side to side, must not exceed 0.075 mm [0.003 in]. The overall flatness, end to end, must not exceed .203 mm (.008 inch) for the 4B and .305 mm (.012 inch) for the 6B. Visually… Read More »