Hydraulic Swivel - Manitowoc Grove CD3340B Service Manual

HYDRAULIC SYSTEM

Hydraulic Swivel

Removal
NOTE: The area around the swivel and the swivel must be
completely cleaned before removing the swivel
from the machine.
1. Stop the engine and engage the parking brake. Before
disconnecting any lines or hoses from the hydraulic
swivel, let the system bleed down for approximately 10
minutes after shutting off the engine.
NOTE: The hydraulic circuits will retain hydraulic pressure
for approximately 10 minutes after the engine is
shut down. Do not disconnect the lines from the
swivel until the pressure has bled down. Even then,
crack each circuit slowly to release any pressure
that might still be in the circuit.
2. Put tags on the hydraulic lines with the number of the
hydraulic port to which the line connects.
3. Disconnect the hydraulic lines from the upper and lower
swivel ports. Be prepared to collect the hydraulic oil in
the lines. Put caps or plugs on the fittings and hydraulic
lines.
4. Remove the stop from the bottom of the swivel.
5. Remove the three bolts and lockwashers securing the
swivel to the mast.
6. Remove the hydraulic swivel.
Disassembly
1. Remove the three hex socket flat head capscrews (1,
Figure 4-36) from flange (2). Remove the flange (2),
O-ring (3) and thrust washer (4). Discard the thrust
washer and the O-ring.
2. Carefully pull the swivel stem (7) from swivel housing
(5). If the swivel can not be pulled from the housing, hit
the top of the swivel shaft with a soft hammer.
3. Remove and discard seals (6), seals (8) and O-rings (9).
4-42
Inspection
Wash the housing and shaft in a suitable solvent. Check the
housing for damage. If there is scoring or deep grooves, the
housing must be replaced.
Use compressed air to remove foreign materials from the
passages in the swivel shaft. Check the shaft for rough
edges that could cause damage to the seals during
installation.
Assembly
1.
2.
3.
4.
5.
6.
7.
8.
Published 04/07/2015 Control # 569-00
Lubricate all seals in the seal kit.
Place the swivel stem (7, Figure 4-36) on the work
bench in the vertical position.
Walk the lower seal (6) down the swivel stem one flow
groove at a time until it reaches the swivel stem base.
Carefully work the seal until it slips into the seal groove
at the swivel stem base.
Install one O-ring (9) into each of the seal grooves of
stem (7). Make sure that the O-ring is not twisted in the
groove.
Slip one seal (8) over the top of the spool and walk the
seal down the swivel one flow groove at a time until it
reaches the bottom seal groove.
A seal assembly tool must now be fabricated from a
piece of 19 mm (3/4 in) wide fiberglass packing tape
approximately 457 mm (18 in) long. Fold the tape in half
with glue sides together (Figure 4-37). No glue can be
exposed on the tape.
See Figure 4-37 and insert the piece of packaging tape
around the seal ring to form a puller. Place the seal ring
into the seal groove over the O-ring. The seal ring will
not fit entirely in the groove.
Using the tape, stretch the seal ring just enough to work
the seal ring over the edge of the flow groove and into
the seal groove. See Figure 4-37. Slowly slide the tape
along the seal until the entire seal is installed in the seal
groove. Be careful not to damage the inside convex
edges of the seal ring. If any seal material is removed
during this procedure, replace the seal with another.
CD3340B/YB4411