Doosan D20G User manual

Vehicle System
Specification
System Operation
Testing & Adjusting
D20G, D25G, D30G with B3.3 Engine
D20G, D25G, D30G with 4TNE98 Engine
G20G, G25G, G30G with G424F Engine
G20G, G25G, G30G with G424FE Engine
SB4219E01
Jan. 2008

1
Important Safety Information
Most accidents involving product operation, maintenance and repair are caused by failure to observe basic
safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations
before an accident occurs. A person must be alert to potential hazards. This person should also have the
necessary training, skills and tools to perform these functions properly.
Read and understand all safety precautions and warnings before operating or performing lubrication,
maintenance and repair on this product.
Basic safety precautions are listed in the “Safety” section of the Service or Technical Manual. Additional safety
precautions are listed in the “Safety” section of the owner/operation/maintenance publication. Specific safety
warnings for all these publications are provided in the description of operations where hazards exist.
WARNING labels have also been put on the product to provide instructions and to identify specific hazards.
If these hazard warnings are not heeded, bodily injury or death could occur to you or other persons. Warnings
in this publication and on the product labels are identified by the following symbol.
Improper operation, lubrication, maintenance or repair of this product can be dangerous and could
result in injury or death. Do not operate or perform any lubrication, maintenance or repair on this
product, until you have read and understood the operation, lubrication, maintenance and repair
information.
Operations that may cause product damage are identified by NOTICE labels on the product and in this
publication.
DOOSAN cannot anticipate every possible circumstance that might involve a potential hazard. The warnings
in this publication and on the product are therefore not all inclusive. If a tool, procedure, work method or
operating technique not specifically recommended by DOOSAN is used, you must satisfy yourself that it is
safe for you and others. You should also ensure that the product will not be damaged or made unsafe by the
operation, lubrication, maintenance or repair procedures you choose.
The information, specifications, and illustrations in this publication are on the basis of information available at
the time it was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and
other items can change at any time. These changes can affect the service given to the product. Obtain the
complete and most current information before starting any job. DOOSAN dealers have the most current
information avail-able.
WARNING

Vehicle System Index3
Index
Specification..................................5
Hydraulic Control Valve.........................................5
Hydraulic Pump ....................................................6
Lift Cylinder...........................................................6
Standard........................................................6
Full Free Triple and Full Free Lift....................7
Tilt Cylinder...........................................................8
Mast .....................................................................9
Carriage................................................................9
Lift Relay Group - Full Free Lift ...........................11
Lift Relay Group - Full Free Triple Lift..................12
Lift & Tilt Mounting Group....................................13
Steering Wheel...................................................14
Steering Gear.....................................................15
Steer Axle and Wheel .........................................16
Steer Wheel Mounting.........................................17
Shoe Brake.........................................................17
System Operation ....................... 18
Hydraulic System................................................18
Basic Schematic - Standard.........................18
Optional Schematic with hyd. locking system ...20
Hydraulic Control Valve................................22
Steering System.................................................27
Steering Cylinder .........................................27
Steering Gear..............................................28
Brake System.....................................................30
Master Cylinder............................................30
Shoe Type Brake.........................................31
Automatic Adjustment..................................31
Parking Brake..............................................31
Testing and Adjusting................ 32
Troubleshooting ..................................................32
Visual Checks ..............................................32
Performance Tests.......................................32
Hydraulic Oil Temperature (Too Hot)............32
Hydraulic System and Mast..........................33
Hydraulic Pump............................................36
Hydraulic Control Valve................................37
Steering System...........................................38
Brake System...............................................39
Parking Brake...............................................40
Hydraulic System................................................41
Relief Valve Pressure Check........................41
Lift Cylinder Air Removal (Only FFT & FFL
Mast)............................................................43
Delayed Engine Shutdown System......................44
Operation.....................................................44
Diagram of Delayed Engine Shutdown System
....................................................................45
Trouble shooting of Delayed Engine Shutdown
System.........................................................46
Diagnostic Fault Codes ................................46
Delayed Engine Shutdown System Schematic
....................................................................47
Delayed Engine Shutdown System Schematic
....................................................................47
Delayed Engine Shutdown System Schematic
....................................................................48
OSS (Operator Sensing System).........................49
Operation.....................................................49
Symbols of OSS...........................................49
Operator Sensing System Schematic ...........50
Trouble shooting of Operator Sensing System
....................................................................51
Mast and Carriage...............................................53
Mast Adjustment...........................................53
Carriage Adjustment.....................................58
Chain Adjustment.........................................59
Chain Wear Test..........................................60
Carriage and Mast Height Adjustment ..........61
Forks Parallel Check....................................61

Vehicle System Index4
Tilt Cylinder Alignment........................................62
Drift Test.............................................................63
Steering System.................................................64
Steer Wheel Bearing Adjustment..................64
Steering Axle Stop Adjustment.....................65
Steering Knuckle Bearing Preload Adjustment
....................................................................65
Steering System Pressure Check.................66
....................................................................66
Brake System.....................................................67
Brake System Air Removal ..........................67
Brake Adjustment.........................................67
Parking Brake Test ......................................71
Parking Brake Adjustment............................71

Vehicle System Specification5
Specification
Hydraulic Control Valve
(1) Torque for bolts that hold control valve sections
together .....................40 ± 3 N·m (360±24 lb·in)
(2) Adjust main system relief valve pressure for lift
and tilt as shown above. See “Relief valve
pressure check” in Testing &Adjusting.
(3) Adjust auxiliary relief value pressure for the
attachment as shown above. See “Relief valve
pressure check” in Testing &Adjusting.
(4) Torque for screws..........6 ± 2 N·m (53±20 lb·in)
CONTROL VALVE
ITEM psi kPa bar Kgf/㎠
EU
USA LIFT TILT (2,630±35) 18,100±250
(181±2.5) (185±2.5)
2.0t NON - EU
NON - USA LIFT TILT (3,130±35) 21,550±250
(216±2.5) (220±2.5)
EU
USA LIFT TILT (2,840±35) 19,500±250
(195±2.5) (199±2.5)
2.5t NON - EU
NON - USA LIFT TILT (3,130±35) 21,550±250
(216±2.5) (220±2.5)
EU
USA LIFT TILT (3,130±35) 21,550±250
(216±2.5) (220±2.5)
3.0t NON - EU
NON - USA LIFT TILT (3,130±35) 21,550±250
(216±2.5) (220±2.5)
ALL ALL Aux (2,040±35) 14,000±250 (140±2.5) (143±2.5)

Vehicle System Specification 6
Hydraulic Pump
(1) Tighten mounting bolts to a torque of
.................................55 ±10 N·m (440±90 lb·in)
(2) Apply Loctite #262.
A372287 for D20/25/30G with B3.3 engine.
Nominal displacement...............................32mL/rev
Rated pressure..............................................25Mpa
Rotation is counter clockwise when seen from drive
end.
Type of pump : Gear
D514289 for D20/25/30G with 4TNE98 Engine.
Displacement..........................................26.5㎤/rev
Rotation is counter clockwise when seen from drive
end.
Type of pump : Gear
A601502 for G20/25/30G
Rotation is counter clockwise when seen from drive
end.
Type of pump : Gear
Displacement.............................................29ml/rev
Lift Cylinder
Flow rate of flow protector
FFL and FFT Mast
D700495....................................45 to 53 liter/min
A215044..................................90 to 106 liter/min
STD Mast
A371156....................................85 to 90 liter/min
Standard
(1) Put pipe sealant on the last three threads of cap.
(2) Torque for setscrew ........6 ±1 N·m ( 53 ±9 lb·in)
NOTE : All seals to be lubricated with hydraulic oil.

Vehicle System Specification7
Full Free Triple Lift and Full Free Lift
Primary
(1) Put pipe sealant on the last three threads of cap.
NOTE : All seals to be lubricated with hydraulic oil.
Full Free Triple Lift And Full Free Lift
Secondary
(1) Put pipe sealant on the last three threads of cap.
NOTE : All seals to be lubricated with hydraulic oil.

Vehicle System Specification 8
Tilt Cylinder
TILT CYLINDER
Model Tilt Gp
Part No.
Forward Tilt
Angle*
Backward
Tilt Angle*
Cyl. Stroke (X)
mm (in)
Cyl. Closed (Z)
mm (in)
A375282 6° 12° 167 (6.57) 514 (20.24)
A375322 6° 6° 110 (4.33) 571 (22.48)
A375324 6° 4° 92 (3.62) 589 (23.19)
D20G, G20G
D25G, G25G
D30G, G30G A375335 6° 10° 148 (5.83) 533 (20.98)
* Permissible tolerance of 1/2°
(1) Adjust pivot eye to dimension (Z) with cylinder
closed.
(2) Torque for bolt............ 95 ±15 N·m (70 ±10 lb·ft)
(3) Torque for head.............................270 ±30 N·m
(200 ±22 lb·ft)
(4) Torque for piston nut......................270 ±30 N·m
(200 ±22 lb·ft)

Vehicle System Specification9
Mast
(1) With mast at 475 mm (18.7 in) channel lap,
equally shim both sides until contact (A) is made
(zero clearance) between bearings and mast
uprights.
(2) With mast at full extension, shim behind pads
until there is clearance (B) between the mast
uprights and the pads of .........0.80 mm (.031 in)
(3) Select lower bearings from the chart to obtain
minimum clearance (C) between bearing and
channel leg for full channel length. Use same
bearing on left and right side.
(See Mast Adjustment in Testing & Adjusting).
MAST BEARING CHART
D581814 Undersize 108.60mm (4.276in)
D581815 Standard 109.60mm (4.315in)
D581816 Oversize 110.70mm (4.358in)
* Permissible tolerance of ±0.08 mm (.003 in).
Carriage
(1) Select bearings from the chart to obtain
minimum clearance (C) between bearings and
channel leg for full channel length. Use same
bearing at all six locations.
(2) Equally shim both sides until contact (A) is
made (zero clearance) between bearings and
inner mast at narrowest point.
(3) Shim bolt as needed to obtain a 6.0 to 9.0 mm
(.236 to .354 in) overlap (B) between bolt (3)
and the carriage stop on the inner upright.(See
Carriage Adjustment in Testing & Adjusting).
(4) Torque for screw.........34 ±7 N·m (360±24 lb·in)
CARRIAGE BEARING CHART
Part No. Bearing Size Bearing OD*
D581814 Undersize 108.60 mm (4.276 in)
D581815 Standard 109.60 mm (4.315 in)
D581816 Oversize 110.70 mm (4.358 in)
* Permissible tolerance of ±0.08 mm (.003 in).

Vehicle System Specification 10
Lift Relay Group-Standard Lift
WARNING
Do not put a lift truck into service if the chain
wear indication is 2% or more. A reading of 2%
or more could cause damage or injury to
persons.
(1) Put LOCTITE NO. 242 Thread Lock on the
threads of the relay group locknuts after
adjustment of the lift chains is completed.
(2) Maximum chain wear....................Less than 2%
(See Chain Wear Test in TESTING &
ADJUSTING).
(3) Distance from bottom of inner mast to bottom of
lower bearing on carriage must be even (flush)
with the inner mast.

Vehicle System Specification11
Lift Relay Group - Full Free Lift
WARNING
Do not put a lift truck into service if the chain
wear indication is 2% or more. A reading of 2%
or more could cause damage or injury to
persons.
(1) Tighten bolts until contact is made with guard.
(2) Put LOCTITE NO. 242 Thread Lock on the
threads of the relay group locknuts after
adjustment of the lift chains is completed.
(3) Maximum chain wear....................Less than 2%
(See Chain Wear Test in TESTING &
ADJUSTING).
(4) Distance from bottom of inner mast to bottom of
lower bearing on carriage must be 41 ±1.5 mm
(1.61±0.6 in).
Bottom of inner mast must be even (flush) with
bottom of stationary mast. Adjust inner first.

Vehicle System Specification 12
Lift Relay Group - Full Free Triple
Lift
WARNING
Do not put a lift truck into service if the chain
wear indication is 2% or more. A reading of 2%
or more could cause damage or injury to
persons.
(1) Maximum chain wear....................Less than 2%
(See Chain Wear in TESTING & ADJUSTING).
(2) Put LOCTITE NO. 242 Thread Lock on the
threads of the relay group locknuts after
adjustment of the lift chains is completed.
(3) Tighten bolts until contact is made with guide
assembly.
(4) Distance from bottom of inner mast to bottom of
lower bearing on carriage must be 41±1.5 mm
(1.61±0.6 in). Bottom of inner mast be even
(flush) with bottom of stationary mast. Adjust
inner mast first.

Vehicle System Specification13
Lift & Tilt Mounting Group
(1) With chains adjusted for equal tension, run mast
to full lift. If mast does not kick (move) to one
side, no shims are needed. If mast does kick
(move) to one side, disconnect cylinder from the
bar on that side. Add shim, connect cylinder,
adjust chains and run mast to full lift to check for
kick. Repeat process if necessary. The total shim
pack must not be more than three shims maxi-
mum.
(2) Install bearing outer race to a depth of (F) .........
.............................. 4.5±0.8 mm (.177±.031 in).
(3) Tilt cylinder installation shown.
(4) Install bearing outer race to a depth of (G)
.............................. 4.5±0.8 mm (.177±.031 in).
(5) (Std Mast Only) Tighten the bolt, until the middle
plastic shim touches the cylinder slightly.
(6) (Std Mast Only) Tighten the nut, until the U-Bolt
touches the cylinder slightly. Repeat procedure
(5), (6), until the torque is to 20 N·m (15 lb·ft).
(7) (Std Mast Only) Tighten the nut, the torque is
55N·m (40lb·ft)
(8) (Std Mast Only) Tighten the nut, the torque is
100N·m (74 lb·ft).

Vehicle System Specification 14
(9) (Full Free Lift Mast Only) :
Tighten nuts until U-bolt is firm against cylinder,
do not apply standard torque.
(10) (Full Free Lift Mast Only):
With chains adjusted for equal tension run mast
to full lift. If mast does not kick (move) to one
side, no shims are needed. If mast does kick
(move) to one side, hold lift cylinder tube on that
side and loosen bearing 1/4 turn and check
mast again. Loosen bearing until kicking
(movement) stops or gap (H) reaches 3.0 mm
(.12 in) (approximately 1.5 turns), whichever is
less. Insert shims (11) under bearing (it may be
necessary to loosen bearing an additional
amount of turns to install shims). Tighten
bearing again.
(12) Tighten the bolt of mounting mast, the torque is
240±40 N·m (177±30 lb·ft).
Steering Wheel
(1) Torque for steering wheel nut......... 60 ~ 70 N·m
(44~52 lb·ft)

Vehicle System Specification15
Steering Gear
(1) Pin (1) in the body must be aligned with internal
pump gear (gerotor) (2) and drive (3) as shown.
(4) Tighten bolts in sequence shown. Tighten to a
first torque of ................................14.1±2.8 N·m
(125±25 lb·in)
Tighten to a final torque of ............28.2±2.8 N·m
(250±25 lb·in)
(5) Torque for plug....................11.3 N·m (100 lb·in)
Plug to be flush (even) with or below mounting
surface.

Vehicle System Specification 16
Steer Axle and Wheel
NOTE : Steer axles with tapered roller bearings
shown.
(1) Do the steps that follow for steer wheel bearing
adjustment.
a. Tighten nut (1) slowly to 135 N·m (100 lb·ft)
while turning the wheel.
b. Loosen nut (1) completely. Tighten it again to
.................................. 50 ±5 N·m (37 ± 4 lb·ft)
c. Insert the pin (2) into lock nut (1) and bend it
over nut.
(3) Torque for bolt that holds pin
..................................... 11 ±1 N·m (100 ±9 lb·ft)
(4), (6) Loosen nuts (5) on both sides. Adjust bolts
(4) to get steering knuckle turning angle (A) of
.......................................................76°to 77.5°
See Steering Axle Stop Adjustment in Testing
And Adjusting section.
(8) Tapered Roller Bearing Axles Only:
Torque for bolts that hold steer cylinder to axle
beam......................250 ± 40 N·m (220 ±30 lb·ft)

Vehicle System Specification17
Steer Wheel Mounting
(1) Torque for bolts and nuts that hold steer wheel
.................................. .120±20 N·m (90±15 lb·ft)
Shoe Brake
(1) Axle shaft bolt...............110±10N·m(81±7.4 lb·ft)
(2) Nut.............................200±10N·m(148±7.4 lb·ft)
(3) Torque for bolts that hold plate to final drive
cover.........................180±30N·m(133±22 lb·ft)
(4) Torque for nuts that hold brake drum to hub
.................................460±20N·m(339 ±15 lb·ft)

Vehicle System System Operation 18
System Operation
Hydraulic System
Basic Schematic - Standard
Basic Hydraulic Actuator System Schematic
(1) Lift Cylinder (2) Flow Protector-primary (3) Lift Cylinder-Primary (4) Flow Protector-Secondary (5) Side Shfit Cylinder
(6) Tilt Cylinder (7) Control Valve (8) Hydraulic Line (To Steering Unit) (9) Relief valve-Auxiliary (10) Relief Valve-Main
(11) Gear Pump (12) Suction Filter (13) Return Filter (14) Hydraulic Tank (15)-(21) Hydraulic Line (22) Flow Regulator Valve
FFT mast
12
Engine
1 6
5
3 1
2
4
STD mast
4
7
11
13 14
8
9
10
15
18
19
20
21
16
22