Komatsu WA450-6, WA480-6 Wheel Loader Service Manual

Table of Contents

00 Index and foreword
01 Specification
10 Structure, function and maintenance standard
20 Standard value table
30 Testing and adjusting
50 Disassembly and assembly
90 Diagrams and drawings

Manual Extract Releasing residual pressure in brake accumulator circuit

Note: Before disconnecting any of the following brake accumulator circuits, release residual pressure in that brake circuits.

-Piping between accumulator charge valve and brake accumulator
-Between accumulator charge valve and parking brake solenoid valve
-Piping between brake accumulator and brake valve on both sides
1. Stop the engine.
2. Press the brake pedal at least 100 times to release the pressure from the brake accumulator circuit.

Testing parking brake performance
-Measurement condition
-Tire inflation pressure: Specified pressure
– Road: 1/5 gradient (11° 20′), flat, and dry road
– Machine: Ready for operation

Measuring method
1. Start the engine and set the machine in the straight travel position, and then drive up a slope of 1/5 gradient with no load in the bucket.
2. Press the brake to stop the machine, set the directional lever in the N position, and stop the engine.
3. Turn the parking brake switch ON (to park), and then release the brake gradually. At this time, the machine must not move.
– When the engine is stopped, the parking brake is turned ON (to park) automatically.
– Measure the parking brake performance on an uphill and a downhill.