Hino 600, Workshop Manual, Page: 267 / 451

SERVICE BRAKE (HYDRAULIC BRAKE) BR02–23
No Braking Effect or Excessive
Pedal Travel Reservoir fluid level low Check for causes of fluid leak, repair
as required and refill the reservoir.
Bleed the system as needed.
Air in the hydraulic system Bleed the system.
Bleed screw loose or open Bleed the system and tighten the
bleed screw.
Caliper piston seal damaged Disassemble the caliper and replace
the piston seals. Replace the piston if
it is damaged.
Excessive rotor runout or bent rotor Check the rotor with a dial indicator.
Install a new rotor if the runout
exceeds the maximum specified.
Worn or excessively loose wheel bear-
ings Adjust or replace the bearings as
needed.
Low quality brake fluid Drain and clean the system. Replace
with the recommended brake fluid.
Weak brake hose that expands under
pressure Replace the hoses.
Brake Noise (Chatter) Excessive lateral runout of rotor Check the runout with a dial indicator.
Install a new rotor if the runout
exceeds the maximum specified.
Lack of rotor parallelism Check the parallelism with a microme-
ter. Resurface or install a new rotor as
required.
Loose wheel bearing Readjust the bearing to the specified
torque.
Brake Noise (Scraping) Rust or mud build-up on edges of rotor
and on caliper housing Clean or replace as necessary.
Worn pad or pad installed backward Replace the pads in the axle sets only
with the friction surface against the
rotor.
Incorrect caliper alignment permitting
rotor to scrape on housing Correct the alignment.
Brake Noise (Groan) Pressure on the brake pedal too light Slightly increase the pedal effort to
eliminate the noise.
Brake Noise (Rattle) Excessive clearance between the shoe
and caliper Install new pads.
Pad retainer spring missing or not cor-
rectly positioned Install a new pad retainer spring or
position it correctly.
Brake Noise (Squeal) Glazed pads Resurface or replace the pads in the
axle sets only.
Weak pad retainer spring Install a new pad retainer spring.
Pad wear indicator contacting rotor Install new pads in the axle sets only.
Foreign material embedded in linings Replace the pads in the axle sets only.
Symptom Possible cause Remedy/Prevention