Hyster N30XMXDR3 Operating instructions

LIFT CYLINDERS
N30XMXDR3, N45XMXR3 [B264]; N30FR; N40-45FR;
N50FA; R30ES; N30XMH, N30XMH2[C210];
N25XMDR3, N30/40XMR3 [C470]; N50XMA3 [C471];
N30XMDR3, N45XMR3 [G138]; W30-40ZA [B453];
W20-30ZR [B455]; W25-30-40ZC [B454];
V30ZMD [D210/E210]; N35ZDR, N45ZR [C264];
N30ZDR, N35-40ZR [D470]; N30ZDRS,
N35-40ZRS [A265]; W25-30ZA2[B495]
PART NO. 897446 4000 SRM 481

SAFETY PRECAUTIONS
MAINTENANCE AND REPAIR
•When lifting parts or assemblies, make sure all slings, chains, or cables are correctly fastened, and
that the load being lifted is balanced. Make sure the crane, cables, and chains have the capacity
to support the weight of the load.
•Donotliftheavypartsbyhand,usealiftingmechanism.
•Wear safety glasses.
•DISCONNECT THE BATTERY CONNECTOR before doing any maintenance or repair on electric
lift trucks. Disconnect the battery ground cable on internal combustion lift trucks.
•Always use correct blocks to prevent the unit from rolling or falling. See HOW TO PUT THE LIFT
TRUCK ON BLOCKS in the Operating Manual or the Periodic Maintenance section.
•Keep the unit clean and the working area clean and orderly.
•Use the correct tools for the job.
•Keep the tools clean and in good condition.
•Always use HYSTER APPROVED parts when making repairs. Replacement parts must meet
or exceed the specifications of the original equipment manufacturer.
•Make sure all nuts, bolts, snap rings, and other fastening devices are removed before using force
to remove parts.
•Always fasten a DO NOT OPERATE tag to the controls of the unit when making repairs, or if the
unit needs repairs.
•Be sure to follow the WARNING and CAUTION notes in the instructions.
•Gasoline, Liquid Petroleum Gas (LPG), Compressed Natural Gas (CNG), and Diesel fuel are
flammable. Be sure to follow the necessary safety precautions when handling these fuels and
when working on these fuel systems.
•Batteries generate flammable gas when they are being charged. Keep fire and sparks away from
the area. Make sure the area is well ventilated.
NOTE: The following symbols and words indicate safety information in this
manual:
WARNING
Indicates a hazardous situation which, if not avoided, could result in
death or serious injury.
CAUTION
Indicates a hazardous situation which, if not avoided, could result in
minor or moderate injury and property damage.
On the lift truck, the WARNING symbol and word are on orange back-
ground. The CAUTION symbol and word are on yellow background.

Lift Cylinders Table of Contents
TABLE OF CONTENTS
General ............................................................................................................................................................... 1
Description ......................................................................................................................................................... 1
Lowering Control Valve................................................................................................................................. 2
Main Cylinder Repair ........................................................................................................................................ 4
Disassemble ................................................................................................................................................... 4
Assemble ........................................................................................................................................................ 5
Free-Lift Cylinder Repair.................................................................................................................................. 6
Disassemble ................................................................................................................................................... 6
Assemble ........................................................................................................................................................ 6
Troubleshooting.................................................................................................................................................. 8
This section is for the following models:
N30XMXDR3, N45XMXR3 [B264];
N30FR; N40-45FR; N50FA; R30ES; N30XMH, N30XMH2[C210];
N25XMDR3, N30/40XMR3 [C470];
N50XMA3 [C471];
N30XMDR3, N45XMR3 [G138];
W30-40ZA [B453];
W20-30ZR [B455];
W25-30-40ZC [B454];
V30ZMD [D210/E210];
N35ZDR, N45ZR [C264];
N30ZDR, N35-40ZR [D470];
N30ZDRS, N35-40ZRS [A265];
W25-30ZA2[B495]
©2008 HYSTER COMPANY i

"THE
QUALITY
KEEPERS"
HYSTER
APPROVED
PARTS

4000 SRM 481 Description
General
This section has the description and repair in-
structions for the lift cylinders used on the
N30FR, N40/45FR, N50FA, R30ES, N30XMH,
N30XMH2, N25XMDR3, N30/40XMR3, N50XMA3,
N30XMDR3, N45XMR3, N30XMXDR3, N45XMXR3,
V30ZMD, W25-30ZA2, W30-40ZA, W25-30-40ZC,
W20-30ZR, N30-35ZDR, N35-40-45ZR, N30ZDRS,
and N35-40ZRS masts. See the section Reach Car-
riages 4500 SRM 971 or Reach Carriages 4500
SRM 1196 for hydraulic cylinder repair instructions
for the reach carriages.
Description
The two-stage masts generally have two main lift
cylinders. However, models W25/30ZA2, W30/40ZA,
and W25/30/40ZC lift trucks with 2 Stage LFL have
only one main lift cylinder centered in the mast. The
three-stage FFL models have two main lift cylinders,
as well as a shorter free-lift cylinder. See Figure 1.
All of these lift cylinders are single-acting cylinders.
The hydraulic force is applied only in one direction.
When hydraulic oil enters one end of the lift cylinder,
the hydraulic force extends the piston rod. When the
force is removed, the weight of the mast components
and carriage causes the piston rod to retract.
These cylinders are also single-stage lift cylinders.
A single-stage lift cylinder has only one rod. See
Figure 1. There are two types of single-stage cylin-
ders used on these lift trucks. One type is the piston
cylinder. The other type is a displacement cylinder.
Trucks may be equipped with either piston or dis-
placement type cylinders or a combination of both.
Piston cylinders operate by hydraulic oil entering
under the piston of the cylinder rod. Seals are used
in the piston to keep the oil from moving from under
the piston to the top of the piston. As the hydraulic
oil raises the piston, the air within the upper part
of the cylinder is compressed into a chamber of the
piston rod. Any oil that is above the piston will be
forced, under pressure, through a check valve back
under the piston.
Displacement cylinders operate by hydraulic oil
entering the cylinder and displacing the rod. Seals
are located in the retainer, and the entire cylinder is
filled with oil. This type of cylinder will have a bleed
screw located near the top of the cylinder to remove
air from the cylinder. The rod of displacement cylin-
ders is almost the size of the inside of the shell. See
Figure 1.
The design and repairs for these displacement cylin-
ders are similar to the other lift cylinders in this sec-
tion. A displacement cylinder does not have a piston
or piston seal. The rod diameter is almost the same
as the inside diameter of the cylinder shell. There are
wear rings on the rod that are the bearings between
the rod and the walls of the cylinder. The wiper seal
atthetopofthecylinderisalsothehigh-pressure
seal for these cylinders. See Figure 3.
1

Description 4000 SRM 481
1. MAIN CYLINDER
2. FREE-LIFT CYLINDER
3. LOWERING CONTROL VALVE
Figure 1. Lift Cylinders
Spacers are used in some cylinders to limit the stroke
of the piston rod. Worn spacers must be replaced
with the same-size spacer.
During operation, some hydraulic oil will leak past
the piston area to the rod end of the lift cylinder.
Small leaks are permitted if the internal leak rate
of the hydraulic system is not greater than the spec-
ification. An internal check valve is installed in the
piston of the main-lift cylinders. When the piston rod
extends, the pressure increases more quickly on any
oil in the rod end of the lift cylinder. The hydraulic oil
transfers through the check valve to the piston end of
the free-lift cylinder. This action prevents hydraulic
damage to the single lip seal and the wiper ring. See
Figure 3.
Lift cylinders and other hydraulic parts can have
some internal leaks. Internal leakage will increase
as the temperature of the hydraulic oil increases.
The internal leak rate of the hydraulic system is
checked periodically. See the sections Periodic
Maintenance 8000 SRM 1197, Periodic Main-
tenance 8000 SRM 970, Periodic Maintenance
8000 SRM 1379, or Periodic Maintenance 8000
SRM 1027, Maintenance Schedule for your lift
truck and Mast,Repair 4000 SRM 482 for test
procedures and leakage rate specifications.
LOWERING CONTROL VALVE
A lowering control valve (also called a velocity fuse)
is installed in the inlet port of each lift cylinder. See
Figure 2. It permits easy entry of hydraulic oil into
the cylinder, but gives a restriction when the rod is
retracted. This restriction limits the speed that a
load on the forks can be lowered.
There are two types of lowering control valves: low-
pressure designs and high-pressure designs. Both
types have the same function and similar operation.
Themostcommontypeofvalvehasadesignthat
has good operation using large flows and lower pres-
sures. Some lift trucks have a lift system design us-
ing higher pressures and a lower flow. These systems
need a different type of lowering control valve.
The most common type of lowering control valve (low
pressure) uses these parts: (1) a special fitting for
the valve body, (2) a spring, and (3) a special washer.
There is a variation in the shapes of the special
washer. Different lift cylinders use different shapes
of special washers. The volume of the hydraulic oil
flowing through the inlet port controls the shape
of the special washer. A typical shape of a special
washerisshowninFigure2. Whenthepistonrod
is lowered, the oil flow pushes against the special
washer and spring. When the oil flow reaches the
limit, the special washer is moved against the spe-
cial fitting. The oil then flows only through the hole
in the center of the special washer. This restriction
permits the piston rod to lower only at a maximum
controlled speed.
2

4000 SRM 481 Description
The other type of lowering control valve (high pres-
sure) uses these basic parts: (1) valve body, (2)
spring, (3) washer, (4) cylinder, (5) orifice sleeve,
(6) plunger, and (7) main sleeve. The orifice sleeve
position is controlled completely by oil flow. The
plunger position is controlled by oil pressure and
spring tension. During lifting, oil entering the lift
cylinder goes through the center of the main sleeve
to the large holes. The oil flow through the plunger
and bore moves the orifice sleeve to the end of the
plunger. The flange of the orifice sleeve is then
aligned with the large part of the bore in the body.
This alignment lets the oil flow past the orifice sleeve
to the cylinder.
During lowering, oil from the lift cylinder moves the
orifice sleeve. The orifice sleeve moves away from the
larger inner diameter area of the bore in the valve
body. This movement makes a restriction to the oil
flow. As the pressure increases, the plunger begins
to move against the spring. The movement begins
to close the openings of the large holes in the main
sleeve. Additional pressure will push the plunger
against the main sleeve to close the large holes com-
pletely. All the oil must then go through the small
holes to the center of the main sleeve. This restric-
tion permits the piston rod to lower only at a maxi-
mum controlled speed.
1. SPECIAL FITTING OR VALVE BODY
2. SPRING
3. WASHER
4. CYLINDER
5. ORIFICE SLEEVE
6. PLUNGER
7. MAIN SLEEVE
Figure 2. Lowering Control Valves
3

Main Cylinder Repair 4000 SRM 481
Main Cylinder Repair
DISASSEMBLE
NOTE: To disassemble and repair a cylinder, the
cylinder must be removed from the mast assembly.
See the section Mast,Repair 4000 SRM 482 to
remove the cylinders from the mast assembly.
WARNING
Use slings and a crane to handle and disassem-
ble the lift cylinders of most lift trucks. Make
sure that the crane and slings can lift the load.
CAUTION
Carefully disassemble and assemble the lift
cylinders in a clean area so that the rods and
sliding surfaces are not damaged.
NOTE: Make a note of the position of the replaceable
parts so that they can be installed in the correct po-
sitions during assembly.
Disassemble the cylinder as follows: See Figure 3.
1. Clean the outside of the cylinder before begin-
ning disassembly to prevent system damage from
dirt.
2. Loosen the retainer using a spanner wrench. Re-
move the retainer from the shell.
3. Remove the cap from the inlet and carefully slide
the piston rod assembly from the shell. Use drain
pans for the hydraulic oil.
4. Remove the retainer from the piston rod. Re-
move and discard the wiper ring, O-rings, seals,
and wear rings.
5. Remove the internal check valve and, if neces-
sary, the floating piston.
6. Remove the lowering control valve.
7. Clean all the parts. Check the sliding surfaces
for damage. Repair or replace any damaged
parts.
8. Discard all seals, O-rings, wipers, and wear
rings.
A. NONCUSHIONED B. CUSHIONED
1. ROD
2. RETAINER
3. WIPER RING
4. SEAL
5. O-RING
6. SHELL
7. CHECK VALVE
8. WASHER
9. SHIM
10. SNAP RING
11. FLOATING PISTON
12. SPACER
13. BACKUP RING
14. WEAR RING
15. LOWERING
CONTROL VALVE
(ALL CYLINDERS)
Figure 3. Main-Lift Piston Cylinder
4

4000 SRM 481 Main Cylinder Repair
NOTE: Inspect the piston rod surface for scratches.
Check the area of the rod where the wiper ring con-
tacts the rod. If scratches are found, use a piece
of crocus cloth to polish the rod. DO NOT polish
lengthwise; use a rotary motion. After the scratch
or scratches have been removed, use another piece of
fine crocus cloth with oil on it to polish the rod. Use
a rotary motion to polish the rod until the finish is
free of scratches and has a fine finish. Clean the rod
thoroughly to remove any metal shavings, before as-
sembly.
ASSEMBLE
NOTE:
•Useasealkittoreplacetheseals. Usetheinstal-
lation sleeves included in the kit. See Figure 4.
•Lubricate all internal parts of the lift cylinder with
hydraulic oil during assembly.
•Use new O-rings, seals, and bearings from the kit.
Apply appropriate lubricant during assembly.
•Make sure the seal assemblies are installed with
the"open"endtowardthebaseoftheliftcylinder.
•The spacer controls the maximum stroke of the pis-
ton rod assembly. If a new spacer is necessary,
make sure the same-size spacer is installed.
1. Install the internal check valve. See Figure 3.
Install the floating piston on applicable units.
Make sure the arrow on the internal check valve
is toward the base of the piston.
2. Install the seal and bearing (and spacer if
equipped) on the piston rod. Use shim material
andaclampasaguidetomovethesealpastthe
threads of the shell.
1. EXTERNAL INSTALLATION SLEEVE
2. SEAL
3. WEAR RING
4. BACKUPRING
5. PISTONROD
6. CYLINDER SHELL
7. INTERNAL INSTALLATION SLEEVE
Figure 4. Seal Installation Sleeves
5

Free-Lift Cylinder Repair 4000 SRM 481
CAUTION
A difficult and important step in assembling
cylinders is the correct installation of the seals
without damage. Most cylinder maintenance is
caused by seal leakage. Special tools are avail-
able in the seal kit for correct installation of
the seals.
3. Carefully push the piston and piston rod into the
shell. Release the clamp on the seal when the
seal travels past the threads of the shell.
4. Install the seals, O-rings, and wiper ring in the
retainer. If the wiper ring has a spring backup
ring, the spring must be toward the base of the
lift cylinder.
5. Carefully install the retainer on the piston rod.
6. Engage the threads and tighten the retainer in
the shell to 340 to 410 N•m (251 to 302 lbf ft).
Use the correct spanner wrench. DO NOT hit
the retainer with a hammer and driver.
CAUTION
Wrong installation of the special washer and
spring can make the load lower too fast.
7. Install the lowering control valve. Make sure the
special washer and the spring are installed cor-
rectly. A wrong installation can cause the load to
lower too fast.
8. See the section Mast,Repair 4000 SRM 482 for
cylinder installation in the mast assembly.
Free-Lift Cylinder Repair
DISASSEMBLE
NOTE: To disassemble and repair a cylinder, the
cylinder must be removed from the mast assembly.
See the section Mast,Repair 4000 SRM 482 to
remove the cylinder from the mast assembly.
WARNING
Use slings and a crane to handle and disassem-
ble the lift cylinders of most lift trucks. Make
sure that the crane and slings can lift the load
correctly.
CAUTION
Carefully disassemble and assemble the lift
cylinders in a clean area so that the piston
rods and sliding surfaces are not damaged.
1. Loosen the retainer with a spanner. Remove the
retainer from the shell. See Figure 5.
2. Remove the protective cap from the inlet and
slide the rod and piston assembly from the shell.
Drain the hydraulic oil into a container.
3. Remove the retainer from the piston rod. Re-
move and discard all O-rings, seals, and bear-
ings.
4. Remove the internal check valve plugs and balls
from thebaseoftherod.
5. Clean all the parts. Check the sliding surfaces
for damage. Repair or replace any damaged
parts.
ASSEMBLE
NOTE: Inspect the piston rod surface for scratches.
Check the area of the rod where the wiper ring con-
tacts the rod. If scratches are found, use a piece
of crocus cloth to polish the rod. DO NOT polish
lengthwise; use a rotary motion. After the scratch
or scratches have been removed, use another piece
of fine crocus cloth with oil on it to polish the rod.
Use a rotary motion to polish the rod until the finish
is free of scratches and has a fine finish. Clean rod
thoroughly to remove any metal shavings, before as-
sembly.
NOTE:
•Useasealkittoreplacetheseals. Usetheinstal-
lation sleeves included in the kit. See Figure 4.
•Lubricate all internal parts of the lift cylinder with
hydraulic oil during assembly.
•Use new O-rings, seals, and bearings. Apply appro-
priate lubricant (hydraulic oil) during assembly.
•Make sure the seal assemblies are installed with
the"open"endtowardthebaseoftheliftcylinder.
6

4000 SRM 481 Free-Lift Cylinder Repair
1. ROD
2. RETAINER
3. WIPER RING
4. SEAL
5. O-RING
6. BACKUP RING
7. BLEED SCREW
AND SEAL
8. SHELL
9. CHAIN ANCHOR
10. LOWERING
CONTROL VALVE
(ALL CYLINDERS)
11. STEEL BALL
12. PLUG
13. WEAR PLUG
Figure 5. Free-Lift Displacement Cylinders
CAUTION
A difficult and important step in assembling
lift cylinders is the correct installation of the
seals. Most lift cylinder maintenance is caused
by seal leaks. Special installation sleeves come
in the seal kits.
1. Install the internal check valve, if installed. See
Figure 5. Make sure the arrow on the internal
check valve is toward the base of the piston.
2. Install the wear ring, single lip seal, and backup
ring onto the piston assembly. If a spacer is used,
installit. Useshimmaterialandaclampasa
guide to move the seal over the threads of the
shell.
3. Carefully push the piston and rod assembly into
the shell. Release the clamp on the seal when the
seal travels past the threads of the shell.
4. Install the seal, O-ring, wear ring, and wiper ring
in the retainer. If the wiper ring has a spring for a
backup ring, the spring must be toward the base
of the lift cylinder.
5. Carefully install the retainer on the piston rod.
6. Engage the threads and tighten the retainer
in the shell to the proper torque. Refer to Ca-
pacities and Specifications 8000 SRM 1198,
Capacities and Specifications 8000 SRM
1028, Capacities and Specifications 8000
SRM 1380, or Capacities and Specifications
8000 SRM 972 for your truck model. Use the cor-
rect spanner wrench. DO NOT hit the retainer
with a hammer and driver.
CAUTION
Wrong installation of the special washer and
spring can make the load lower too fast.
7. Install the lowering control valve. Make sure the
special washer and the spring are installed cor-
rectly. A wrong installation can cause the load to
lower toofast.
8. See the section Mast,Repair 4000 SRM 482 for
cylinder installation in the mast assembly.
7

Troubleshooting 4000 SRM 481
Troubleshooting
PROBLEM POSSIBLE CAUSE PROCEDURE OR ACTION
No movement of lift cylin-
ders. No oil or not enough oil supply to lift cylinder. Check oil level and add oil as needed.
Hydraulic leaks, damaged hydraulic
pump, or damaged hydraulic pump
drive.
Repair hydraulic leaks. Replace
pump or pump drive. Replace check
valve. Reset relief valve to correct
setting.
Relief valve setting wrong or check
valve damaged. Adjust relief valve setting. Replace check valve.
Slow action of the lift cylin-
ders. Not enough oil supply to the lift cylinder. Check oil level and add oil as needed.
Bad cylinder seal. Check for internal
leaks. Install a gate valve in the hy-
draulic line. Raise the mast. Close
thegatevalve. Seeifthemastorcar-
riage slowly lowers because of an in-
ternal leak.
Replace cylinder seals.
Low relief valve setting. Adjust relief valve to correct setting.
Rough movement of the mast
assembly. Air in the hydraulic system. Remove air from hydraulic system.
Bent pistonrod,orcylindershellis
damaged. Replace cylinders.
Mast assembly is damaged or not in
alignment. Repair damage or realign mast as-
sembly.
8

TECHNICAL PUBLICATIONS
4000 SRM 481 4/08 (11/06)(10/06)(5/04)(4/03)(5/98)(4/97)(1/96)(12/95)(6/92) Printed in U.S.A.