With ABS

DESCRIPTION

Master Cylinder:

A vehicle equipped with ABS uses a different master cylinder than a vehicle that is not equipped with ABS. Vehicles equipped with ABS use a center port master cylinder while vehicles not equipped with ABS use a compensating port master cylinder.
On vehicles equipped with ABS, the master cylinder is a two port design, one primary and one secondary. The brake tubes from the primary and secondary outlet ports on the master cylinder go directly to the Hydraulic Control Unit (HCU).


OPERATION
When the brake pedal in depressed, the master cylinder primary and secondary pistons apply brake pressure through the chassis brake tubes, ABS hydraulic control unit, and proportioning valves to each brake assembly. On ABS master cylinders, the primary outlet port supplies hydraulic pressure to the right front and left rear brakes. The secondary outlet port supplies hydraulic pressure to the left front and right rear brakes.