81128514 SP1 Volvo NH12 Twin Cylinder Compressor

What does a twin cylinder compressor do?

This twin cylinder compressor functions as a critical engine-driven unit within the air brake system of heavy commercial vehicles, generating the compressed air required for braking and pneumatic operations. By utilizing two piston-cylinder assemblies, it provides superior air output and faster reservoir filling compared to single-cylinder alternatives. This specific model is engineered with heavy-duty grade materials to withstand high-pressure cycles and thermal stress during continuous operation.

Vehicle compatibility and engine fitment

This unit is specifically compatible with Volvo NH12 trucks equipped with D12A engines. It features a through-drive design and is designed to integrate seamlessly into the engine's cooling circuit via M16x1,5 water inlet and outlet ports. The assembly includes a water-cooled valve plate to manage operating temperatures effectively under heavy loads.

Installation and maintenance guidance

For correct installation, technicians should verify that the air inlet port (Ø29) and outlet port (M26x1,5) match the existing vehicle lines. Ensure the M22x1,5 unloader port and water connections are secured to prevent pressure drops or leaks. Regular inspection of the cooling lines and port integrity is recommended to maintain optimal system performance.

Selection and replacement advice

When selecting a replacement, always confirm that the mounting flange and drive gear configuration match the removed unit to ensure perfect fitment within the engine compartment.

OE cross-reference

1300 050 006 (Twin Cylinder Compressor) is the equivalent of the Volvo OE number. This part directly replaces Volvo OE number 81128514SP1.