Valve Stem Seal Cummins 3957912 | J957912, 5287011, 192110

High-Performance Valve Stem Seal for Cummins Engines

The Cummins 3957912 Valve Stem Seal is a critical component designed to control oil flow within the valvetrain. By sealing the gap between the valve stem and the valve guide, this seal prevents engine oil from leaking into the combustion chamber. This helps maintain optimal combustion efficiency, reduces blue exhaust smoke, and lowers overall oil consumption.

Product Specifications & Features

• Premium Quality: Manufactured to meet or exceed factory specifications for a perfect fit and reliable sealing performance.
• Durable Construction: Made from premium temperature-resistant elastomer (Viton) to withstand the harsh environment of the cylinder head.
• Dimensions:
  • Spring Seat Diameter: 33.3 mm
  • Guide Install Inner Diameter: 13.8 mm
  • Valve Seal Inner Diameter: 7.70 mm
• Design Type: New style (“Top Hat” integrated seal and spring seat) introduced after April 2003.

Engine Compatibility

This valve stem seal is compatible with the following Cummins diesel engines:

• Cummins 4BT 3.9L
• Cummins 6BT 5.9L
• Cummins ISB 3.9L
• Cummins ISB 5.9L

Note: This is the newer style seal used on engines manufactured after April 2003. If your cylinder head currently uses the older-style separate seals, machining may be required for installation. Please verify your engine serial number (ESN) before ordering.