Hyster D024 Operating instructions

Hyster D024 (S135FT S155FT) Forklift Service
Repair Manual

GM 4.3L V-6 ENGINES
S4.0-5.5FT, S5.5FTS (S80-120FT;
S80-100FTBCS; S120FTS; S120FTPRS)
[G004, H004];
H4.0FT5/FT6; H4.5FTS5, H4.5FT6; H5.0-5.5FT
(H80-120FT) [N005, P005, R005, S005, U005];
H6.0-H7.0FT; (H135-155FT)
[H006, J006, K006, L006];
S6.0-7.0FT; (S135-155FT)
[D024, E024, F024, G024]
PART NO. 1627339 0600 SRM 1251

SAFETY PRECAUTIONS
MAINTENANCE AND REPAIR
• The Service Manuals are updated on a regular basis, but may not reflect recent design changes to the
product. Updated technical service information may be available from your local authorized Hyster®
dealer. Service Manuals provide general guidelines for maintenance and service and are intended for
use by trained and experienced technicians. Failure to properly maintain equipment or to follow in-
structions contained in the Service Manual could result in damage to the products, personal injury,
property damage or death.
• 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.
• Do not lift heavy parts by hand, use a lifting mechanism.
• 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 ex-
ceed 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 flamma-
ble. 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.

©2015 HYSTER COMPANY
TABLE OF CONTENTS
General .....................................................................................................................................................................1
Engine Removal and Installation ...........................................................................................................................1
Cylinder Head Repair ............................................................................................................................................. 2
Remove and Disassemble ................................................................................................................................... 2
Clean and Inspect ............................................................................................................................................... 4
Valve Oil Seals .................................................................................................................................................... 6
Remove and Disassemble ...............................................................................................................................6
Cylinder Leak Down Test .......................................................................................................................... 7
Clean and Inspect ........................................................................................................................................... 7
Assemble and Install ...................................................................................................................................... 8
Valve Guides and Seats, Repairs ..................................................................................................................... 10
Valves, Repair ................................................................................................................................................... 11
Valve Seats, Repair ...........................................................................................................................................11
Valve Springs .................................................................................................................................................... 12
Assemble and Install ........................................................................................................................................ 13
Engine Block Cleaning and Inspection ................................................................................................................ 18
Clean and Inspect ............................................................................................................................................. 18
Piston Bore Preparation ........................................................................................................................................20
Engine Mounts Installation ..................................................................................................................................21
Remove .............................................................................................................................................................. 21
Clean and Inspect ............................................................................................................................................. 21
Install .................................................................................................................................................................21
Lubrication System Repair ...................................................................................................................................22
Oil Pump, Remove and Disassemble ............................................................................................................... 22
Clean and Inspect ............................................................................................................................................. 23
Oil Pump, Assemble and Install .......................................................................................................................24
Oil Pan, Install ..................................................................................................................................................26
Timing Cover, Timing Sprockets, Camshaft, and Valve Lifters .........................................................................28
Timing Cover .....................................................................................................................................................28
Remove .......................................................................................................................................................... 28
Install ............................................................................................................................................................ 30
Timing Sprockets .............................................................................................................................................. 30
Remove .......................................................................................................................................................... 30
Install ............................................................................................................................................................ 30
Camshaft ........................................................................................................................................................... 30
Remove .......................................................................................................................................................... 30
Inspect ........................................................................................................................................................... 31
Install ............................................................................................................................................................ 31
Balance Shaft .................................................................................................................................................... 32
Remove .......................................................................................................................................................... 32
Install ............................................................................................................................................................ 33
Valve Lifters ......................................................................................................................................................34
Remove .......................................................................................................................................................... 34
Clean and Inspect ......................................................................................................................................... 34
Install ............................................................................................................................................................ 35
Crankshaft Repair .................................................................................................................................................36
Remove .............................................................................................................................................................. 36
Inspect and Repair ............................................................................................................................................36
How to Check Clearance Between Main Bearings and Their Journals .........................................................37
Install .................................................................................................................................................................38
Table of Contents
i

TABLE OF CONTENTS (Continued)
Piston and Connecting Rod Assemblies Repair ...................................................................................................40
Connecting Rod Bearings, Replace .................................................................................................................. 40
Piston and Connecting Rod Assemblies, Remove ............................................................................................41
Disassemble .......................................................................................................................................................41
Piston, Clean and Inspect .................................................................................................................................42
Cylinder Bores, Inspect and Repair ................................................................................................................. 42
Piston Rings ...................................................................................................................................................... 43
Assemble ............................................................................................................................................................44
Piston and Connecting Rod Assemblies, Install ..............................................................................................44
Flywheel and Flywheel Housing Repair .............................................................................................................. 45
Flywheel, Remove ............................................................................................................................................. 45
Clean ..................................................................................................................................................................45
Inspect ............................................................................................................................................................... 45
Flywheel, Install ............................................................................................................................................... 46
Coolant Pump Repair ............................................................................................................................................46
Remove .............................................................................................................................................................. 46
Clean and Inspect ............................................................................................................................................. 47
Install .................................................................................................................................................................47
Thermostat Replacement ......................................................................................................................................48
Remove .............................................................................................................................................................. 48
Thermostat Operation Check ...........................................................................................................................48
Install .................................................................................................................................................................48
Starter Replacement ............................................................................................................................................. 49
Remove .......................................................................................................................................................... 49
Install ............................................................................................................................................................ 52
Fan Assembly Replacement ..................................................................................................................................53
Remove .............................................................................................................................................................. 53
Inspect ............................................................................................................................................................... 55
Install .................................................................................................................................................................55
Drive Belt Installation .......................................................................................................................................... 56
Remove .............................................................................................................................................................. 56
Clean ..................................................................................................................................................................56
Inspect ............................................................................................................................................................... 56
Installation ........................................................................................................................................................ 56
Compression Check ............................................................................................................................................... 57
Engine Specifications ............................................................................................................................................ 58
Engine Data .......................................................................................................................................................58
Cylinder Head ................................................................................................................................................... 58
Hydraulic Valve Lifter ......................................................................................................................................58
Camshaft ........................................................................................................................................................... 58
Pistons ............................................................................................................................................................... 59
Crankshaft .........................................................................................................................................................59
Connecting Rods ................................................................................................................................................60
Balance Shaft .................................................................................................................................................... 60
Cooling System ..................................................................................................................................................60
Lubrication System ...........................................................................................................................................60
Torque Specifications ............................................................................................................................................ 60
Table of Contents
ii

This section is for the following models:
S4.0-5.5FT, S5.5FTS (S80-120FT; S80-100FTBCS; S120FTS; S120FTPRS) [G004,
H004];
H4.0FT5/FT6; H4.5FTS5, H4.5FT6; H5.0-5.5FT (H80-120FT) [N005, P005, R005,
S005, U005];
H6.0-H7.0FT; (H135-155FT) [H006, J006, K006, L006];
S6.0-7.0FT; (S135-155FT) [D024, E024, F024, G024]
Table of Contents
iii

"THE
QUALITY
KEEPERS"
HYSTER
APPROVED
PARTS

General
CAUTION
Disconnect the battery cables before doing any
disassembly and repair of the engine or parts of
the electrical system.
The diodes and resistors in the electrical system
can be damaged if the following cautions are not
followed:
• DO NOT disconnect the battery when the
engine is running. The voltage surge can
damage the diodes and resistors.
• DO NOT disconnect an electric wire before
the engine is stopped and the switches are
OFF.
• DO NOT cause a short circuit by connection
of the electric wires to the wrong terminals.
Make sure a correct identification of the
wire is made before it is connected.
• Make sure a battery is the correct voltage
and polarity before it is connected.
• DO NOT check for current flow by making a
spark because the electronic components
can be damaged.
This SRM has repair instructions for GM 4.3 liter,
V-6 engine. Checks and Adjustments and
Specifications are also included.
Engine Removal and Installation
The Removal and Installation procedures for the engine are in the Frame section for each model of lift
truck. If engine and transmission were removed from lift truck as a unit, see Transmission sections to sep-
arate transmission from engine.
The Removal and Installation procedures for the gasoline and LPG components of the engine are covered in
the Gasoline Fuel System and LPG Fuel System sections for each model of lift truck.
0600 SRM 1251 General
1

Cylinder Head Repair
REMOVE AND DISASSEMBLE
WARNING
Disconnect the battery cables before making re-
pairs to the engine.
1. Drain cooling system.
2. Loosen hose clamp and remove coolant hose
from thermostat housing.
NOTE: Prior to removing distributor, mark loca-
tion of distributor on distributor and engine to aid
in proper installation. For more information re-
garding removal and installation of distributor, see
High Voltage Switch (HVS) Ignition; GM4.3L
EPA Compliant Engines and GM5.7L LPG
EPA Complicant Engine 2200SRM1097.
3. Remove air cleaner, distributor, intake mani-
fold, and exhaust manifolds. Remove drive
belt(s) and remove brackets for drive belt ten-
sioner and alternator.
4. Remove spark plugs and spark plug wire
shields.
5. Remove valve rocker arm cover bolts and grom-
mets. Discard grommets.
6. Remove rocker arm cover. See Figure 1.
7. Remove valve rocker arms. Organize rocker
arms so they can be installed in their original
positions. See Figure 2.
1. ROCKER COVER BOLTS
2. ROCKER COVER
3. CYLINDER HEAD
Figure 1. Rocker Cover Removal
Cylinder Head Repair 0600 SRM 1251
2

8. Remove valve rocker arm supports.
9. Remove valve push rods.
1. VALVE ROCKER ARM
2. VALVE ROCKER ARM SUPPORT
3. PUSH ROD
Figure 2. Remove Valve Rocker Arm and Push
Rod
10. Remove capscrews that hold cylinder head to
block in the sequence shown in Figure 3. Re-
move cylinder head and gasket. Discard cylin-
der head gasket.
A. FAN END
Figure 3. Cylinder Head Capscrew Removal
Sequence
11. Using a valve spring compressor, remove valve
stem keys, caps, springs, and oil seals. Discard
oil seals. Remove valves. Organize valves and
springs so they can be installed in their original
positions. See Figure 4.
0600 SRM 1251 Cylinder Head Repair
3

1. VALVE STEM KEYS
2. VALVE SPRING CAP
3. VALVE SPRING
4. VALVE
5. VALVE STEM OIL SEAL
6. CYLINDER HEAD
Figure 4. Valve Removal
CLEAN AND INSPECT
1. Clean carbon from valve ports and combustion
chambers in cylinder head. Use care not to scuff
the combustion chambers.
WARNING
Cleaning solvents can be flammable and toxic and
can cause skin irritation. When using cleaning
solvents, always follow the solvent manufactur-
er's recommended safety procedures.
WARNING
Compressed air can move particles so they cause
injury to the user or to other personnel. Make sure
the path of the compressed air is away from all
personnel. Wear protective goggles or a face
shield to prevent injury to the eyes.
2. Using cleaning solvent, clean following items:
• Valve stem keys
• Valve spring cap
• Valve spring
• Valve
• Cylinder head
When cleaning is complete, dry components with
compressed air. See Figure 5.
1. VALVE STEM KEYS
2. VALVE SPRING CAP
3. VALVE SPRING
4. VALVE
5. VALVE STEM OIL SEAL
6. CYLINDER HEAD
Figure 5. Valve Component Cleaning
Cylinder Head Repair 0600 SRM 1251
4

3. Clean valve guides.
CAUTION
To prevent possible gouging of the cylinder head
surfaces, use care when removing gasket mate-
rial.
4. Remove all gasket material from surfaces of
cylinder head.
5. Inspect cylinder head for following defects:
• Damage to gasket surfaces
• Damage to threaded bolt holes
• Burnt or eroded areas in combustion
chamber
• Cracks in exhaust ports and combustion
chambers
• External cracks in water chamber
• Restrictions in intake or exhaust pas-
sages
• Restrictions in cooling system passages
• Rusted, damaged, or leaking core plugs
6. Measure cylinder head for warpage with a
straight edge and feeler gauge. See Figure 6.
• A cylinder head block deck with warpage
in excess of 0.10 mm (0.004 in.) within a
152.4 mm (6.0 in.) area must be repaired
or replaced.
• A cylinder head exhaust manifold mount-
ing surface with a warpage in excess of
0.05 mm (0.002 in.) within a
152.4 mm (6.0 in.) area must be repaired
or replaced.
• A cylinder head intake manifold mount-
ing surface with a warpage in excess of
0.10 mm (0.004 in.) within a
152.4 mm (6.0 in.) area must be repaired
or replaced.
Figure 6. Cylinder Head Warpage Inspection
7. Inspect valves for:
• Burnt or damaged areas
• Undersized margin
• Bent stem
• Scoring or other damage to stem
• Worn key groove
• Worn stem tip
See Figure 7.
0600 SRM 1251 Cylinder Head Repair
5

1. BURNT OR DAMAGED AREAS
2. UNDERSIZED MARGIN
3. BENT STEM
4. SCORING/DAMAGE TO THE STEM
5. WORN KEY GROOVE
6. WORN STEM TIP
Figure 7. Valve Inspection
Valve stems with excessive guide clearance must
be repaired or replaced. Refer to Engine Specifi-
cations.
8. Inspect valve contact surface for the following:
• Undersized margin
• Pitted surface
• Burnt or eroded areas
• Acceptable edge margin
See Figure 8.
Valves with excessive damage must be replaced.
Minor imperfections of valve or valve seat may
be repaired. Refer to Valve Guides and Seats,
Repairs or Valves, Repair.
VALVE OIL SEALS
The following procedure addresses replacement of
valve oil seals. If ONLY valve oil seals are being re-
placed, it is not necessary to remove the cylinder
head.
1. UNDERSIZED MARGIN
2. PITTED SURFACE
3. BURNT OR ERODED AREAS
4. ACCEPTABLE EDGE MARGIN
Figure 8. Valve Contact Surface Inspection
Remove and Disassemble
1. Remove spark plug wires from spark plugs and
position spark plug wires out of way.
2. Remove each spark plug and spark plug wire
shield.
NOTE: If spark plugs are not being replaced label
each spark plug to its corresponding cylinder.
3. Remove rocker cover bolts and grommets. Dis-
card grommets. Repeat for other rocker cover.
4. Remove rocker covers. Disconnect the Positive
Crankcase Ventilation valve from the air inlet
hose.
5. Perform cylinder leak down test for each cylin-
der. See Cylinder Leak Down Test.
6. Remove valve rocker arms. Organize rocker
arms so they can be installed in their original
positions. Repeat for other side.
Cylinder Head Repair 0600 SRM 1251
6

7. Using a valve spring compressor, remove valve
stem keys, caps, springs, and oil seals. Discard
oil seals. Organize springs so they can be in-
stalled in their original positions. Repeat for
other each cylinder.
Cylinder Leak Down Test
NOTE: Rotate crankshaft to place piston in cylin-
der being tested at top dead center (TDC) of the
compression stroke, with both valves closed. Lock
crankshaft balancer in place to prevent piston
movement.
1. Install the J 35667-A Cylinder Head Leakdown
Tester (Hyster P/N 4060759) tester in the spark
plug port on cylinder to be tested.
2. Apply shop air pressure to J 35667-A Cylinder
Head Leakdown Tester (Hyster P/N 4060759)
tester and adjust according to manufactures in-
structions.
3. Record cylinder leakage value. Cylinder leak-
age exceeding 25 percent is considered exces-
sive and may require component service.
Air leakage from intake or exhaust system may
indicate a worn or burnt valve or a broken valve
spring.
• Ensure that both valves are closed.
• Inspect cylinder head for a broken valve
spring.
• Remove and inspect suspect cylinder head.
See Cylinder Head Repair, Remove and
Disassemble.
Air leakage from crankcase, oil level indicator, or
oil fill tube may indicate worn piston rings, a
damaged piston, a worn or scored cylinder bore,
a damaged engine block or a damage cylinder
head.
• Remove piston from the suspect cylinder.
See Piston and Connecting Rod Assem-
blies, Remove.
• Inspect piston and connecting rod assem-
bly. See Piston, Clean and Inspect.
• Inspect engine block. See Engine Block,
Clean and Inspect.
• Inspect cylinder head. See Cylinder Head
Repair, Clean and Inspect.
Air bubbles in cooling system may indicate a
damaged cylinder head or a damaged cylinder
head gasket.
• Remove both cylinder heads. See Cylinder
Head Repair, Remove and Disassemble.
• Inspect engine block. See Engine Block,
Clean and Inspect.
• Inspect cylinder head. See Cylinder Head
Repair, Clean and Inspect.
Clean and Inspect
WARNING
Cleaning solvents can be flammable and toxic and
can cause skin irritation. When using cleaning
solvents, always follow the solvent manufac-
turer’s recommended safety procedures.
WARNING
Compressed air can move particles so they cause
injury to the user or to other personnel. Make sure
the path of the compressed air is away from all
personnel. Wear protective goggles or a face
shield to prevent injury to the eyes.
1. Using cleaning solvent, clean the following
items:
• Valve stem keys
• Valve spring cap
• Valve spring
2. When cleaning is complete, dry components
with compressed air. See Figure 9.
0600 SRM 1251 Cylinder Head Repair
7

1. VALVE STEM KEYS
2. VALVE SPRING CAP
3. VALVE SPRING
4. VALVE
5. VALVE STEM OIL SEAL
6. CYLINDER HEAD
Figure 9. Valve Component Cleaning
3. Clean valve guides.
Assemble and Install
1. Using GM tool J-42073 (Hyster P/N 4622265),
install oil seal in lower groove. Install shim,
damper, spring, shield, and cap or rotator. Us-
ing a spring compressor, compress assembly
and install retainers. Measure height of valve
spring as shown in Figure 13. Measure from top
of shim to top of retainer cap. Install shims to
get correct height shown in Figure 10. The in-
stalled height of valve spring must not be less
than minimum height.
NOTE: THIS LIST IS FOR 4.3L GASOLINE EN-
GINES.
A. VARIATION FROM VERTICAL: LESS THAN
1.6 mm (0.063 in.)
B. FREE LENGTH: 51.3 mm (2.02 in.)
C. SPRING COMPRESSED TO 338 TO 374 N (76
TO 84 lbf) AT 43.2 mm (1.70 in.) CLOSED
SPRING COMPRESSED TO 832 TO 903 N (187
TO 203 lbf) AT 32.3 mm (1.27 in.) OPEN
D. INSTALLED HEIGHT INTAKE: 42.92 TO
43.43 mm (1.670 TO 1.700 in.) EXHAUST: 42.92
TO 43.43 mm (1.670 TO 1.700 in.)
NOTE: THIS LIST IS FOR 4.3L LPG ENGINES.
A. VARIATION FROM VERTICAL: LESS THAN
1.6 mm (0.063 in.)
B. FREE LENGTH: 50 mm (2.0 in.)
C. SPRING COMPRESSED TO 265 N (59.5 lbf) AT
43.2 mm (1.70 in.) CLOSED SPRING COM-
PRESSED TO 718 N (161.5 lbf) AT
32.3 mm (1.27 in.) OPEN
D. INSTALLED HEIGHT INTAKE: 42.92 TO
43.43 mm (1.670 TO 1.700 in.) EXHAUST: 42.92
TO 43.43 mm (1.670 TO 1.700 in.)
Figure 10. Valve Spring Specifications
Cylinder Head Repair 0600 SRM 1251
8

2. Apply a molybdenum grease or equivalent to
following valve rocker arm contact surfaces:
• Valve push rod socket
• Roller pivot
• Valve stem tip
See Figure 11.
1. VALVE PUSH ROD SOCKET
2. ROLLER PIVOT
3. VALVE STEM TIP
4. ROCKER ARM BOLT
Figure 11. Lubricate Valve Rocker Arm Surfaces
3. Install valve rocker arm assemblies as follows:
a. Finger start rocker arm bolt at location 1
in Figure 12.
b. Finger start rocker arm bolt at location 2
in Figure 12.
c. Finger start rocker arm bolt at location 3
in Figure 12.
d. Finger start remaining three valve
rocker arm bolts.
Repeat for other side.
1. BOLT AT LOCATION 1
2. BOLT AT LOCATION 2
3. BOLT AT LOCATION 3
Figure 12. Install Valve Rocker Arm Assemblies
4. Rotate crankshaft balancer to position crank-
shaft balancer alignment mark 57 to 63 degrees
clockwise or counterclockwise from engine front
cover alignment tab. See Figure 13.
0600 SRM 1251 Cylinder Head Repair
9

NOTE: ONCE THE VALVE ROCKER ARM ASSEM-
BLIES ARE INSTALLED AND PROPERLY TOR-
QUED, NO ADDITIONAL VALVE LASH ADJUST-
MENT IS REQUIRED.
1. CRANKSHAFT BALANCER ALIGNMENT MARK
2. ENGINE FRONT COVER ALIGNMENT TAB
Figure 13. Rotate Crankshaft Balancer
5. Tighten valve rocker arm bolts to 30 N•m (22
lbf ft). See Figure 19. Repeat for other side.
6. Use new gasket and install rocker covers. In-
stall new grommets on capscrews and install
capscrews into rocker covers. Tighten cap-
screws to 12 N•m (107 lbf in). See Figure 22.
Repeat for other side.
7. Install air inlet hose on PCV valve. Tighten
clamp.
8. Install each spark plug wire shield and spark
plugs.
9. Install spark plug wires to their appropriate
spark plugs.
VALVE GUIDES AND SEATS, REPAIRS
Measure clearance between valve stem and guide
as follows:
1. Clamp a dial indicator on exhaust port side
of the cylinder head. See Figure 14.
2. Position dial indicator so that movement of
valve stem from side to side, crosswise to cyl-
inder head, will cause a direct movement of
dial indicator stem.
The dial indicator stem must contact side of
valve stem just above valve guide.
3. Lower valve head about 1.6 mm (0.063 in.)
below valve seat.
4. Using light pressure, move valve stem from
side to side in order to obtain valve stem-to-
guide clearance reading.
See Engine Specifications for maximum clearances.
If clearance is more than maximum amount, over-
size valves or new valve guides must be installed.
Use a reamer of correct size when installing new
valve guides. Use normal service procedures when
grinding valve seats. See Engine Specifications for
dimensions.
1. VALVE STEM
2. DIAL INDICATOR
Figure 14. Valve Steam Clearance
Cylinder Head Repair 0600 SRM 1251
10

VALVES, REPAIR
NOTE: Before any work is performed on valve
faces and seats, make sure clearance of valve stems
in their valve guides is within specifications.
A correction for minimum wear and damage to
valve and seat can be done by a process called lap-
ping. When th valve seats are lapped, keep valve
faces and seats within the specifications. Make sure
all of the lapping compound is removed from the
valve and valve seat when the process is completed.
Valves with minor pits in valve faces can be ma-
chined to proper angle. There are many different
types of equipment for repairing valve faces. Follow
instructions of manufacturer of equipment that you
are using. Valves must be machined to proper spec-
ifications. See Figure 15.
NOTE: SEAT WIDTH DIMENSION APPLIES TO THE
46° FACE ONLY.
1. CYLINDER HEAD
Figure 15. Valve Seat Specifications for Inlet and
Exhaust Valves
Replace a valve if any of the following conditions
are present:
• Valve stem is worn below specifications.
• Valve stem is bent.
• Valve face is warped.
• Any part of valve is cracked.
• Any wear or damage to valve face that can-
not be removed by resurfacing and still meet
specifications shown in Figure 16.
Figure 16. Valve Head Measurements
VALVE SEATS, REPAIR
NOTE: Before any work is done on valve faces and
seats, make sure clearance of valve stems in their
valve guides is within specifications.
Damaged valve seats can be resurfaced with a tool
that is designed to repair valve seats. There are
many different types of equipment for repairing
valve seats. Follow the instructions of the manufac-
turer of the equipment that you are using.
The valve seats are ground at three different an-
gles: 30°, 46°, and 60°. This method makes a valve
seat that is proper width and produces the correct
contact line between the valve and valve seat. The
specifications for valve seats are shown in the En-
gine Specifications section and in Figure 15.
• If contact line is too high, it can be made
lower by using a 30° stone.
• If contact line is too low, it can be raised us-
ing the 46° stone.
• If seat is too narrow, it can be made wider
using a 46° stone.
• If seat is too wide, it can be made narrower
using a 60° stone.
The correct dimensions for the valve seat widths
and valve/valve seat overlap are shown in Fig-
ure 17. The valve seat widths are the dimensions of
46° face only. The valve/valve seat overlap is dis-
tance from the edge of the seat to outside edge of
valve.
0600 SRM 1251 Cylinder Head Repair
11

A. EXHAUST VALVE B. INTAKE VALVE
1. CYLINDER HEAD 2. VALVE
Figure 17. Valve Seat Widths and Valve/Valve Seat Overlap
VALVE SPRINGS
Measure length of valve springs. The correct length
is 51.6 mm (2.03 in.).
WARNING
Be careful when testing the valve springs. These
springs can come loose with enough force to
cause an injury. Always use equipment that was
designed to test springs. Always wear eye and
face protection while testing valve springs.
Use a special tool to check tension of valve springs.
Compress the spring to correct height and check
tension. For correct specifications, see Figure 18.
Replace valve springs that are not within specifica-
tions.
Cylinder Head Repair 0600 SRM 1251
12

NOTE: THIS LIST IS FOR 4.3L GASOLINE EN-
GINES.
A. VARIATION FROM VERTICAL: LESS THAN
1.6 mm (0.063 in.)
B. FREE LENGTH: 51.3 mm (2.02 in.)
C. SPRING COMPRESSED TO 338 TO 374 N (76
TO 84 lbf) AT 43.2 mm (1.70 in.) CLOSED
SPRING COMPRESSED TO 832 TO 903 N (187
TO 203 lbf) AT 32.3 mm (1.27 in.) OPEN
D. INSTALLED HEIGHT INTAKE: 42.92 TO
43.43 mm (1.670 TO 1.700 in.) EXHAUST: 42.92
TO 43.43 mm (1.670 TO 1.700 in.)
NOTE: THIS LIST IS FOR 4.3L LPG ENGINES.
A. VARIATION FROM VERTICAL: LESS THAN
1.6 mm (0.063 in.)
B. FREE LENGTH: 50 mm (2.0 in.)
C. SPRING COMPRESSED TO 265 N (59.5 lbf) AT
43.2 mm (1.70 in.) CLOSED SPRING COM-
PRESSED TO 718 N (161.5 lbf) AT
32.3 mm (1.27 in.) OPEN
D. INSTALLED HEIGHT INTAKE: 42.92 TO
43.43 mm (1.670 TO 1.700 in.) EXHAUST: 42.92
TO 43.43 mm (1.670 TO 1.700 in.)
Figure 18. Valve Spring Specifications
ASSEMBLE AND INSTALL
1. Install each valve in correct port. Install oil seal
in lower groove. Install shim, damper, spring,
shield, and cap or rotator. Using a spring com-
pressor, compress assembly and install retain-
ers. Measure height of valve spring as shown in
Figure 18. Measure from top of shim to top of
retainer cap. Install shims to get correct height
shown in Figure 18. The installed height of
valve spring must not be less than minimum
height.
2. Clean surface of cylinder head and top of cylin-
der block. Make sure threads in block are clean.
If threads are not clean, use a thread chaser to
clean threads.
3. Install cylinder head gasket and cylinder head.
Make sure cylinder head is aligned with pins in
block.
4. Use sealant Hyster P/N 1451215 on threads of
capscrews for cylinder head. Install capscrews
as follows:
a. Tighten all capscrews to 30 N•m (22 lbf ft).
Use sequence shown in Figure 19.
b. Tighten capscrews 11, 7, 3, 2, 6, 10 an addi-
tional 55 degrees. Tighten capscrews 12 and
13 an additional 65 degrees. Tighten cap-
screws 1, 4, 8, 5, 9 an additional 75 degrees.
A. FAN END
Figure 19. Cylinder Head Tightening Sequence
0600 SRM 1251 Cylinder Head Repair
13