Manitowoc Grove CD3340B Service Manual page 265

CD3340B/YB4411
WARNING
Before repairing the parking brake, make sure that the
machine is on level ground. Place chocks on both sides of
th e f ou r ti r e s . R em ov e t he ig ni t io n k e y. If th es e
precautions are not adhered to, the crane could run you
over while performing the repair.
NOTE: When removing seals and backup rings be careful
not to scratch or mar the pistons.
The new linings must be kept free of grease, oil,
etc.
1. Close the needle valve located under the accumulator
(Figure 9-7). This will shut off hydraulic pressure to the
parking brake. Release system pressure by actuating
the service brake pedal until no resistance is felt. Then,
engage and disengage the parking brake to release its
pressure.
2. Slowly, loosen the hydraulic hose from the parking
brake. Some pressure may still be present in the
hydraulic hose. Let the pressure escape and then
remove the hydraulic hose.
3. Cap the hydraulic hose to prevent contamination from
entering the hydraulic system.
4. Loosen lock nut (8, Figure 9-10) and back off adjusting
bolt (7).
5. Remove the bolts and nuts used to fasten the brake
mounting bracket assembly to the crane. Remove the
parking brake assembly.
6. Separate the mounting
Figure 9-10) from the brake assembly.
7. Clamp the brake in a vice with soft jaws with the cover
(3) in a vertical position.
NOTE: Clamping should be done on sides of the brake, not
on machined surfaces.
8. Remove bleeder screw (30).
9. Using a sharp bladed tool, carefully remove two seals
(28) from housing (26). Note the direction the seals were
installed.
NOTE: Cap (3) is under spring pressure. Use care when
removing the cap to prevent personal injury.
10. Loosen but do not remove four capscrews (1). Loosen
screws evenly in the order of A, B, C and D as shown in
Figure 9-11 until spring preload is released.
GROVE
bracket assembly (31,
Published 04/07/2015 Control # 569-00
A0783
11. Remove capscrews (1), lockwashers (2), cover (3) and
gasket (23). Using a thin blade screw driver, remove
seal (4) from cover (3).
12. Remove belleville springs (5) and if present, washer (6).
When removing the belleville springs take note of the
stacking sequence.
13. Remove piston (9) from housing (26) bore. Remove O-
ring (11) and back-up ring (10) from the piston. Push rod
(12) should also come out with piston (9).
14. Remove piston (15) from housing (26) bore. Remove O-
rings (13 and 16) and back-up rings (14 and 17) from
piston (15).
15. Remove lining and piston assembly (22) from housing
(26) bore. Holding assembly on a flat surface, separate
lining (20) and piston (19) by removing two flat head
screws (21). Remove O-rings (18) from piston (19).
16. Loosen vice jaws and rotate the brake so that the disc
clearance slot is facing upward. Remove pan head
screws (27), lining (25) and bushings (24) from housing
(26).
17. Lubricate all rubber components (NOT THE BRAKE
LININGS) in clean hydraulic oil. Use the same type as
used in the hydraulic system.
18. Clean all parts (EXCEPT LININGS) and housing bore
thoroughly with a suitable solvent and then coat them
with clean hydraulic oil of the same type used in the
hydraulic system. Keep all parts free of contaminants,
dirt and debris.
NOTE: Coat the surfaces indicated in Figure 9-10 with a
Lithium Base, E.P. No. 2 bearing grease or
equivalent.
19. Install new lining (25) in housing (26) using new
bushings (24) and pan head screws (27). Tighten the
screws to 2.5-3.3 Nm (22-28 lb-in).
BRAKE SYSTEM
FIGURE 9-11
9
9-9