Two-Stage Mast
4000 SRM 764
WARNING
Commercial
cleaning
solvents
can
be
flammable and toxic and can cause severe
skin irritation.
When using commercial
cleaning solvents, always comply with the
solvent manufacturer’s recommended safety
precautions.
5.
Clean the mast weldments with steam or solvent.
WARNING
Do NOT weld on masts. Get information from
your Hyster lift truck dealer before welding on
masts.
6.
Inspect the sliding and rolling surfaces. Inspect
the welds around the stub shafts.
LIFT CYLINDERS
NOTE:
The lift cylinders are removed during disas-
sembly of the mast. To repair the cylinders, see the
section Lift Cylinders 4000 SRM 135 for the correct
service procedures.
ASSEMBLE
NOTE:
The shims for the load rollers keep the chan-
nels of the mast weldments parallel and give correct
clearance. During assembly, the arrangement of the
shims will be the same or approximately the same as
they were before disassembly. Check the clearance
and adjust for wear or changes from the repairs. The
strip bearings at the top of the outer mast weldment
and the bottom of the inner mast weldment are also
adjusted using shims. See the Checks and Adjust-
ments in this section for the instructions to make the
necessary adjustments.
1.
Assemble the load rollers, sheaves, and strip
bearings on the mast weldments and operator
platform as necessary. Make sure to keep the
same shim arrangement noted during disassem-
bly. Apply a thin layer of multipurpose grease
to the strip bearings and the bearing and roller
surfaces of the channels.
2.
Make sure the cylinders are assembled and in-
stall a sling near the center of the cylinder as
during removal. Use a crane to move the cylinder
into position in the outer mast weldment. Install
the snap ring on the bottom of the cylinder. In-
stall the capscrew, washer, and spacer to fasten
the cylinder shell to the channel. Repeat the pro-
cedure to install the other cylinder.
3.
Use the crane to move the inner mast weldment
into position over the outer mast weldment. Fas-
ten the slings to the centers of the channels to
balance the weldment as during removal. Make
sure the inner mast weldment is at approxi-
mately a 30-degree angle with the bottom load
rollers in the notch near the top load rollers of
the outer mast channels. Slowly lower the inner
mast weldment and insert it into the outer mast
weldment.
4.
Check the clearance of the load rollers and the
strip bearings. Make the necessary adjustments
as described in Mast Adjustments.
5.
With the inner mast weldment approximately
152 to 305 mm (6 to 12 in.) out of the outer mast
weldment, install the chain and hose sheaves.
Move the inner mast weldment into the outer
mast weldment so the tops of the cylinder rods
are through the holes in the inner mast channels.
Install the washers and snap rings to fasten the
cylinder rods to the channels.
INSTALL
NOTE:
If two hoists are available, connect one to the
mast and the other to the base of the platform for
stability. This will allow for easier mounting of the
mast. Make sure the hoist and chains or straps have
the capacity to lift the mast assembly.
1.
Attach a chain or strap to the top of the mast and
elevate the mast with the hoist. Ensure the mast
cable on the mast is secure during installation of
the mast.
2.
On the chassis frame, the mast trunnion caps
and capscrews allow the mast to attach securely
to the frame. Remove the two bolts and caps on
both sides of the chassis frame if they were rein-
stalled after the initial removal of the mast. See
Figure 6.
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