Terex RT700 - Parking Brake Troubleshooting; Air Pressure Issues

TROUBLESHOOTING
PARKING BRAKE WON’T APPLY
CAUSE REMEDY
Restricted hose or tube..........................................................................Remove restriction or replace.
Defective relay valve.............................................................................Repair or replace.
Defective spring brake valve.................................................................Repair or replace.
Defective control valve .........................................................................Repair or replace.
PARKING BRAKES WON’T RELEASE
CAUSE REMEDY
Insufficient system air pressure.............................................................Allow engine to run to increase pressure to above 70
p.s.i.
Restricted hose or tube..........................................................................Remove restriction or replace.
Insufficient hold off pressure ................................................................Check for system (or excessive valve) leaks.
Leaking brake actuator diaphragm........................................................Replace brake actuator (spring pot).
Defective relay valve.............................................................................Repair or replace relay valve.
Defective spring brake valve.................................................................Repair or replace spring brake valve.
Defective control valve .........................................................................Repair or replace control valve.
INADEQUATE AIR PRESSURE
CAUSE REMEDY
Leaks in system.....................................................................................Repair leaks.
Frozen lines ...........................................................................................Thaw out lines.
Defective compressor............................................................................Inspect for sticking unloader valve, replace if neces-
sary.
Reservoir leaking...................................................................................Replace.
Tank to compressor supply line damaged.............................................Replace.
PARKING BRAKE
RT700 Series Page 5 - 13 Issued: August 2003
AIR PRESSURE