TOPIC 3. LIFT CYLINDERS

TM 10-3930-644-14&P

TOPIC 3. LIFT CYLINDERS

A. GENERAL

3. Remove the crosshead assembly, ram

The hydraulic oil enters the lift cylinder at or near the

protecting rod, chain and guard from cluster

base of the cylinder causing the plunger to extend.

cylinder assembly.

A flow regulator, located at the oil inlet port of the lift

4. Remove cylinder cluster retaining nut (or

cylinder, controls the outflow of hydraulic oil so that the

retaining plate as applicable) at bottom of outer

load lowers at a controlled rate of speed from the raised

mast.

position.

5. Remove the capscrews.

lockwashers, and

B. MAINTENANCE

.spacers at the top of the Inner mast upright.

1. 50 Hour Inspection

6. Carefully remove the cylinder cluster from the

After each 50 hours of operation, inspect the

outer and inner masts.

mast lift cylinder, cylinder hoses, and fittings for

evidence of leaks and repair as necessary.

NOTE

Refer to REPAIR MANUAL for

2. 100 Hour Inspection

DISASSEMBLY, INSPECT:

ON,

REPAIR and REASSEMBLY.

After each 0l0 hours o operation, wipe oil and

foreign matter from lift chains and inspect them

LIFT CYLINDER-CLUSTER

INSTALLATION

for bent or cracked links. Use a I" paint brush

(20-55 SERIES)

and lubricate both sides of chains with SAE 20

engine oil. Wipe off excess oil with a clean rag.

CAUTION

If chains are loose or carriage is not level, the

Prior to lift cylinder installation, be

chains must be adjusted. (Refer to following

certain that all hoses and fittings are

Paragraph E. LIFT CHAIN ADJUSTMENT.)

clean and that there is no foreign

matter in the cylinder inlet port.

3. 500 Hour Inspection

1. install all fittings and clamps previously removed

Approximately every 500 hours of operation,

from cylinder, and install the low regulator.

remove the lift chains from mast assembly and

clean them in an oil solvent solution (50% SAE-

2. To install the cylinder cluster assembly, first

30 nondetergent engine oil and 50% suitable

ensure that the crosshead assemblies and ram

cleaning solvent). Soak chains in oil-solvent

protectors have been correctly installed at the

solution for about four (4) hours and agitate then

outer cylinder rims, and that the chair adjusting

several times during the soaking period.

screws and locknuts have been installed.

Remove chains from oil solvent and wipe off all

of the cleaning solution. Inspect lift chains for

3. Attach a properly rated hoist chain to the

wear and broken or cracked links. Replace

cylinder cluster assembly and maneuver cluster

entire chain if any links are broken or cracked.

assembly into its relative mounting position

Install the chains; then use a 1" paint brush and

within the inner and outer masts.

lubricate both sides of chains with SAE-20

engine oil. Wipe off excess oil with a clean

4. Install attaching capscrews and lockwashers

cloth. Adjust chains so fork carriage is level and

which secure the cylinder cluster to inner mast.

all slack is removed from the lift chains.

Tighten mounting capscrews.

5. install and reconnect

the

cylinder

cluster

C. LIFTCYLINDER-CLUSTER REMOVAL (20-55

adjusting screws.

SERIES)

1. With lift cylinders fully retracted and carriage

resting on ground, disconnect lift chains from

NOTE

cylinder cluster.

Refer to LIFT CHAIN ADJUSTMENT

2. Disconnect hydraulic hoses, and fittings

Paragraph E of this Topic, prior to

(including flow-regulator), and plug or cap all

operational use of lift truck.

hydraulic openings to prevent entry of any

contaminants.

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