HYDRAULIC AND PARK BRAKE SYSTEMS
Bleeding the Hydraulic Brake System
2001 Pioneer 1200 Gasoline Vehicle Maintenance and Service Manual Page 6-29
6
BLEEDING THE HYDRAULIC BRAKE SYSTEM
Read WARNING on page 6-1.
To properly function, the hydraulic system must be free of air. Air in the hydraulic system will result in a
“spongy” brake pedal. Air enters the hydraulic system whenever the system is opened as a result of service
or a leak occurs. Air may also enter the system if the brakes are applied when there is very little hydraulic
fluid in the brake fluid reservoir.
The master cylinder controls two separate hydraulic sub-systems. The front two wheels are connected to the
smaller, front portion of the brake fluid reservoir, and the rear wheels are connected to the rear, larger portion
of the brake fluid reservoir. Depending on where the hydraulic system was opened, bleeding of only the front
or rear hydraulic brake sub-system may be required. In some situations, bleeding of both the front and rear
brake sub-systems will be required. To bleed both the front and rear hydraulic brake sub-systems, use the fol-
lowing procedure to first bleed the two front brakes and repeat the procedure to bleed the two rear brakes.
1. Check the brake pedal and master cylinder push rod for proper adjustment before proceeding. See
Brake Pedal Adjustment, Section 5, Page 5-1.
Figure 6-22 Front and Rear Brake Bleeding
REGULATED
AIR PRESSURE
12 - 15 PSI
(82.7- 103.4 kPa)
