Haldex #A840, Air Over Hydraulic Brake Actuator Assembly, SC12 Type 12 Chamber, Cast Iron Master Cylinder, 150 psi

Used in heavy-duty truck and trailer air-over-hydraulic brake systems, this assembly combines a Haldex SC12 Type 12 service brake chamber with a cast iron master cylinder body to convert compressed air pressure into hydraulic braking force. The Haldex SC12 air chamber features a powder-coated steel housing, an orange alert stroke indicator, a self-piloting dust shield, and air port threads of 3/8-18 NPTF with a maximum rated air pressure of 150 PSI. The diaphragm chamber casting reads 12SC12 with date code 099A18A. The cast iron master cylinder body is cast and machined in the USA, with casting number FE51033 visible on the body. The assembly is mounted on a heavy gold zinc-coated steel bracket with welded hardware. This type of air-over-hydraulic actuator assembly is commonly used on medium and heavy-duty commercial vehicles, vocational trucks, and trailers where the towing vehicle supplies compressed air to activate hydraulic wheel brakes. Cross-references for the Wagner-style power cluster family include A840, AF840, A838, AF838, and A839. The cast iron cylinder body shows surface oxidation and patina consistent with storage or prior installation. The Haldex SC12 chamber presents in cosmetically sound condition. Serial and casting markings are legible. MPN confirmed from casting: FE51033. Verify fitment and pressure ratings against your specific application before installation.

Stock # 0526-02530