8-17. BRAKE HYDRAULIC PRESSURE SWITCH TEST/REPLACEMENT (CONT)
With engine off, pump brake pedal a
minimum of 20 times to exhaust stored brake
Remove brake hydraulic pressure switch (3)
from elbow (4) on brake control valve (5).
Tag, mark, and disconnect two connectors
(1) of vehicle wiring harness (6) from
connectors (2) on brake hydraulic
pressure switch (3).
Place suitable container under brake
control valve to catch spilling hydraulic
· Hydraulic oil in system can be under pressures over 3000 psi (20,685 kPa) with engine OFF.
ALWAYS relieve pressure in hydraulic hoses before attempting to remove any component in
hydraulic system. With engine OFF, starter switch in RUN position, and attachment on ground,
move control levers through all operating positions several times to relieve hydraulic pressure.
Relieve pressure in hydraulic oil tank by loosening filler cap very slowly. Failure to follow these
precautions could result in serious injury or death to personnel.
· At operating temperatures, hydraulic oil is hot and under pressure. Hot oil can cause injury to
personnel. Allow hydraulic oil to cool before disconnecting any hydraulic hoses.
· If inner or intermediate sections of boom have been removed, cap three hydraulic hoses at
underside of outer boom with metal caps. If attachment has been removed, cap three hydraulic
hoses at front of boom with metal caps. Failure to do so may result in injury to personnel caused by
hydraulic oil spraying out of open hoses or lines when engine is started.
· Ensure Step (1) of Removal has been performed before performing Step (2)(c) below. Serious
injury to personnel from hydraulic oil under pressure can result if brake system pressure is not
exhausted before switch is removed.
Remove brake hydraulic pressure switch (3) from nipple (7) on elbow (4) on brake control valve (5).
Remove nipple (7) from elbow (4) at brake control valve (5).