Brake Fluid Pump: Description and Operation

Fig. 3 Hydraulic pump assembly:

Fig. 4 Accumulator assembly:

The electric high-pressure pump, Fig. 3, runs for short periods to charge the hydraulic accumulator which supplies the service brake system.The accumulator, Fig. 4, is a gas filled pressure chamber which is part of the pump and motor assembly. The entire assembly is shock-mounted to the master cylinder and booster.

NOTE: If pump motor runs continuously for 20 minutes, a thermal safety switch (located in the motor) will shut motor off. A 2 to 10 minute cool-down is typical before operation can resume.