Bleeding Brake System - Komatsu WB140-2N Operation & Maintenance Manual

MAINTENANCE
If the machine is equipped with air conditioning as well as external filter
(3) there is also an additional internal filter (6) for internal air recircula-
tion. This is a filter that holds the impurities present in the air and it
must be cleaned whenever a decrease in the air circulation is observed.
The filter can be reached from inside the cab. To clean the filter element,
it is necessary to proceed as follows:
1. Remove screws (4), remove outer guard (5), and remove filter ele-
ment (6).
2. Tap element lightly on the palm of your hand to remove dust and
blow compressed air on its surfaces, keeping the jet at a distance of
about 15 cm (5.9 in) and making sure that the pressure does not
exceed 4-5 bar (58-73 psi).
3. Carefully clean the filter casing, taking care to prevent any foreign
debris from entering the suction duct, and then reassemble the unit.

BLEEDING BRAKE SYSTEM

• Oil spilled on the floor may cause it to become slippery;
immediately clean any dirty area.
• Oils, filters, coolant, and the battery are considered spe-
cial waste and must be collected and disposed of
according to all anti-pollution regulations in force.
This operation is important, since it helps maintain the power and
braking efficiency of the machine. Proceed as follows:
1. Make sure that oil in braking system tank (3) reaches the maximum
level.
2. Depress each brake pedal and keep it depress while loosening drain
screw (1) for each brake, until pedal reaches the end of its stroke.
Use a 13 mm wrench.
3. Keep pedal at the end of its stroke while tightening drain screw (1).
4. Release the brake pedal, wait for a few minutes and repeat opera-
tions described above until no air bubbles can be seen in the oil that
flows out of drain screw (1).
When bleeding the system, attach a small hose to screws (1), In
order to collect the oil.
Bleeding must be carried out for both braking units, discon-
necting the tandem pedals from each other.
Frequently check oil level in the brake system tank and top off whenever oil is near the minimum level.
When adding oil, use only new oil of the prescribed type, See "FUEL, COOLANT, AND LUBRICANTS" on page 3-
7.
3-58 WB140-2N, WB150-2N