Grove
Published 01-14-2021 Control # 707-01
8-53
TMS9000-2 SERVICE MANUAL
CARRIER
8
Troubleshooting Brakes
Spring Brake Actuator
The upper part of the brake air chamber containing the large
spring is not serviceable; however, the lower part of the
assembly is serviceable.
Manually Caging the Spring Brake
1.
Remove the caging bolt and washer from its storage
hole on the outside of the brake chamber.
2.
Remove the dust cap from the bolt hole in the top of the
chamber.
3.
Insert the head of the caging bolt through the opening
and turn bolt 1/4 turn clockwise.
4.
Thread the nut and washer on the bolt and turn the nut
clockwise about 18 to 21 turns. Air pressure can be
applied to the spring brake chamber through the parking
port to compress the spring while the nut is being
tightened.
5.
Do not force the nut beyond its normal stop. A torque of
40.6 Nm (30 lb-ft) is the maximum that should be
required. Reverse the procedure to uncage the spring.
SYMPTOM
PROBABLE CAUSE
SOLUTION
Brakes are poor or do not apply.
Insufficient air pressure.
Check for correct pressure at compressor and
brake chambers.
Restriction or leak in lines, valves, etc.
Check all lines, valves, etc., for leaks or
restrictions.
Brakes are out of adjustment.
Adjust the brakes.
Leaking diaphragm.
Replace diaphragm.
Uneven braking or lining wear.
Ruptured diaphragm.
Replace diaphragm.
Brakes are out of adjustment.
Adjust brakes.
Grease on the lining.
Replace lining.
Glazed lining.
Replace lining.
Shoes are installed backwards.
Reverse shoes.
Combination linings.
Replace with correct style.
Automatic adjusters are not
working.
Adjusting pawl installed backwards.
Remove and properly install pawl.
Pawl is collapsed or missing.
Replace spring.
Bolt is frozen in adjusting sleeve.
Free-up or replace the bolt.
Detent is damaged allowing the bolt to rotate
with sleeve.
Replace damaged detent.
Double lip seals are not installed correctly.
Remove and correctly install seals.
Spring brake is not holding.
Power spring is not fully released.(uncaged).
Turn caging bolt fully counterclockwise until stop
is reached.
Brakes are out of adjustment.
Readjust the brakes.
Hold-off air is not releasing fully.
Check for faulty air system components.
Power spring is broken.
Replace spring brake actuator.
Brake is dragging.
Low spring brake hold-off air pressure 482
kPa (70 psi).
Check for minimum spring brake pressure 482
kPa (70 psi). Check for proper functioning of air
system components.
Improper connection of the service line at
spring brake.
Check and connect line to proper port.
Leaking lines or spring brake seals.
Tighten connections on air lines or replace spring
brake unit seals.
WARNING
Death or Injury Could Occur!
Spring brake unit is powerful enough to cause parts to fly
apart with enough force to cause personal injury. The
spring brake must be caged before removing or servicing
brakes. Uncage the spring brake before returning the
crane to service.
Fo
r
Reference
Only
