Hydraulic Modulator/Pump

Depressurize brake system. See DEPRESSURIZING BRAKE SYSTEM  . Turn ignition on. Hydraulic modulator/pump should operate for 60 seconds maximum and then stop. Depress brake pedal a few times; pump should operate again for a few seconds. If pump motor does not operate, check electrical system. If pump motor operates for more than 60 seconds, internal or external hydraulic leak may be indicated. Check for external leaks. If external leak is not found, further testing may be needed to check for internal leaks.