Product Description
The Bendix 2512139 Hydrovac Brake Booster is a Fourth Series single-diaphragm vacuum/hydraulic brake booster designed for older medium-duty commercial vehicles equipped with vacuum-assisted hydraulic brake systems. The remanufactured Haldex equivalent is sold as RV2512139X.
The Hydrovac uses engine vacuum to increase hydraulic braking force, reducing driver pedal effort while providing the additional brake assist required by heavier commercial vehicles. This configuration features a 12-3/4-inch diameter diaphragm housing and measures approximately 18-5/8 inches overall.
The 2512139 uses 5/16-inch inverted-flare hydraulic inlet and outlet ports, a 3/4-inch air-cleaner connection, and a 1/2-inch NPT vacuum supply connection. It uses End Cap H and an MB-2 three-stud mounting bracket, which helps distinguish it from several similar Fourth Series Hydrovac assemblies.
The 2512139 is particularly associated with older Ford medium-duty trucks, including F-600, F-700, and F-800 configurations. Because several Hydrovac boosters share a similar appearance, verify the original part number, port sizes, overall length, and mounting-bracket configuration before ordering.
Part Number: 2512139
Reman References: 2512139X, RV2512139X
Product Type: Vacuum/Hydraulic Brake Booster
Series: Bendix Fourth Series
Design: Single Diaphragm
Diameter: 12-3/4 in.
Overall Length: 18-5/8 in.
Hydraulic Inlet: 5/16" Inverted Flare
Hydraulic Outlet: 5/16" Inverted Flare
Air Cleaner Connection: 3/4 in.
Vacuum Supply: 1/2" NPT
End Cap: H
Mounting Bracket: MB-2
Core Group: VAC1004
