Anti-Lock/Traction Control: Bleeding: Notes

The ABS/TCS must be bled any time that air is permitted to enter the hydraulic system due to disconnection of hydraulic pipes or hoses. It is important to both that air in the hydraulic system will not cause a spongy pedal feel or additional pedal travel. The ABS/TCS monitors booster piston travel and boost pressure and may set a diagnostic trouble code due to air in the brake system.

ABS/TCS bleeding information is divided into 3 parts, including: pump and booster bleeding, pressure bleeding of wheel circuits and master cylinder as well as manual bleeding of wheel circuits and master cylinder.

The pump and booster must be bled of service is performed which involves removal of the pressure hose (pump to hydraulic unit), return hose (hydraulic unit reservoir to pump) or pump/motor assembly. The pump and booster also must be bled if the reservoir has been emptied or removed.

The individual wheel circuits must be bled if any hose or pipe fittings has been disconnected or if any caliper has been removed from the car. If it becomes necessary to bleed the pump and booster, it may also be necessary to bleed all wheel circuits. Wheel circuits may be bled manually or with a pressure bleeder.