Tools and Special Tools
Engine Shut Down
91B, Light Wheel Vehicle Mechanic (2)
Visually inspect for brake valve for mount security, luid leaks at the valve, ittings, and brake lines/hoses and
for any damage affecting serviceability.
END OF TASK
Ohms test brake fails switch BFS (FO-1) for no continuity (Open). Brake fail switch BFS is a normally open switch
therefore no continuity should exist. Replace BFS if continuity is measured.
END OF TASK
Before servicing brake system components, make sure that the machine is on level ground.
Set the hand brake.
The use of Personal Protective Equipment (PPE) is required when using or handling hazardous
materials associated with operating and maintaining equipment (jet fuel, hydraulic luid, brake
luid, ethylene glycol, cleaning solvents, compressed air, and engine/axle oil). Failure to use
PPE when handling these materials could result in injury or death.
Place a drip pan under the brake valve.
Disconnect 2 brake hoses (Figure 1, Item 5 and 8) and plug.
Disconnect 2 brake lines (Figure 1, Item 7 and 10) and plug.
Remove brake valve mount nuts and bolts (Figure 1, Item 6 and 12) (nuts not shown).
Allow brake valve to drop (Figure 1, Item 11).
Remove brake switch screws (Figure 1, Item 1) and washers (not shown).
Remove switch wires (Figure 1, Item 13 and 14).
Remove brake valve ittings (Figure 1, Item 3 and 5) as assemblies noting orientation.
Remove brake valve (Figure 1, Item 11).
Remove brake valve switch (Figure 1, Item 2).