HYDRAULIC AND AIR SYSTEMS 2250 SERVICE/MAINTENANCE MANUAL
2-14
Published 11-06-15, Control # 040-13
DISC BRAKE OPERATIONAL TEST
General
There is no physical way to check the disc brakes for travel,
boom hoist, luffing hoist, front/rear drums, and swing. An
operational test of each brake must be performed weekly.
Figure 2-17
shows brake and brake solenoid valve locations.
Operational Test
NOTE: For all pumps, system pressure is preset at 5,500
to 6,500 psi (379 to 448 bar).
Electrical plugs at brake solenoid valves must be
disconnected to stall crane functions during tests.
1. Start engine and allow it to idle at 1,500 RPM.
2. Select and confirm SETUP mode (faulty pressures will
be recorded in any other mode).
NOTE: For load drums, make sure crane is in full power
mode.
3. Disconnect electrical plug for brake being checked.
4. Scroll to corresponding diagnostics screen for brake
being checked. Monitor pump pressure and pump
command while moving control handles.
5. For all functions, move control handle in both directions,
one at a time, to check brake operation in both
directions.
6. Slowly move handle for function being checked.
Specified system pressure must be reached before 50%
pump command is reached and brake must not slip.
7. Reconnect electrical plugs at all brake solenoid valves at
completion of operational test.
8. If disc brakes were repaired or replaced, retest brakes
before operating with a load.
CAUTION
Overheat Hazard!
Do not hold any function on stall for more than 10
seconds. Damage to system components may occur.
WARNING
Falling Load/Moving Crane Hazard!
If any disc brake slips when operational test is performed,
repair or replace corresponding brake before placing
crane back into service. Loads could fall or crane could
move if brakes are not operating properly.
For load drums with a disc brake on both ends of drum,
repair or replace both disc brakes.
See planetary manufacturer’s manual for disc brake repair
instructions.
Legend for Figure 2-17
Item
Description
1 Travel Disc Brake Solenoid Valve (both brakes)
2 Luffing Hoist Disc Brake Solenoid Valve
3 Swing Disc Brake Solenoid Valve
4 Luffing Hoist Disc Brake
5 Luffing Hoist Planetary
6 Case Drain Port
7 Swing Disc Brake
8 Swing Planetary
9 Front Drum Disc Brake Solenoid Valve
10 Right Rear Drum Disc Brake Solenoid Valve
11 Left Rear Drum Disc Brake Solenoid Valve
12 Load Drum Planetary
13 Case Drain Port
14 Travel Disc Brake
15 Case Drain Port
16 Crawler Input Planetary
17 Boom Hoist Planetary
18 Boom Hoist Disc Brake
19 Case Drain Port
20 Boom Hoist Brake Solenoid Valve
21 Electrical Plug (typical)
22 Boom Hoist Planetary Fill Sight Gauge
To Next Page
Loading...
Need help?
General
