Peterbilt Medium Duty Trucks Operator's Manual after 1-07

Preventive Maintenance
Make sure that the fluid level registers on or above the fluid
level mark molded on the reservoir - add more if necessary,
as follows:
1. Remove each reservoir cap and extract the rubber diaphragm
from each reservoir.
2. Fill each reservoir with clean hydraulic fluid of the
approved specification (DOT 3 brake fluid).
3. Insert the rubber diaphragms into the reservoirs.
REFILL CAPS
BOOSTER AND MASTER CYLINDER ASSEMBLY
4. To prevent leakage from the reservoirs, ensure that the
seal in each reservoir cap is in good condition before
refitting the cap.
Brake System
WARNING! If the brake fluid reservoir requires an
excessive amount of hydraulic fluid, the complete
system must be inspected for leaks and
repaired if necessary (consult your nearest
Peterbilt dealer). Failure to keep the brake system
in good repair may lead to loss of braking
and possibly cause serious personal injury.
Service Brake Component Inspection
Remove each wheel to inspect the brake components.
CAUTION: When replacing disc brake pads, be
sure to use the same lining material on both
axles. Mixing lining types can result in unbalanced
braking, increased pad wear, or degraded
stopping performance. Consult your nearest
Peterbilt dealer.
Disc brake pads - Visually inspect all brake pad linings.
Brake pads should be replaced when the
remaining lining reaches 3⁄16 inch thickness or
less.
It is recommended that all disc brake pads be
replaced at the same time since this will maintain
balanced braking. At a minimum, replace all
disc brake pads on one axle, both ends, at the
same time.
Medium Duty (R10/06) Y53-6008 – 155 –