Hyster H3.50–5.50XM (H70–120XM) Forklift Service Manual Set, 2003–2005 (P/N 1559545)

The Powershift operating descriptions explain the oil circuits used by the corresponding repair and pressure-test sections. Together, they let technicians relate transmission symptoms to circuit operation and component checks.

Coverage limits: Selected shared chapters also list S3.50-5.50XM (S70-120XM) [E004, F004]; this collection is not a complete S-series manual set. Internal Perkins engine repair is for the L005 1104 (RE). The separate K005 1004-42 engine repair section, 600 SRM 705, and Hydrostatic Transmission Troubleshooting and Repairs, 1300 SRM 801, are not included.

Hydrostatic configurations receive maintenance procedures, wiring, hydraulic schematics, pressure/capacity data and indicator information. Lift and tilt cylinder repair is covered; mast disassembly is referred to the applicable mast manual.

Searchable Text and Diagram Access

Search and drawing detail: The PDFs contain searchable text, but many labels inside schematic images cannot be searched. Section bookmarks are usable in 26 files; the bookmarks in Diagrams.pdf all lead to its cover. Small wiring labels require zooming.

The ZIP contains 27 printable PDFs totaling 1,166 pages, including 27 covers, 47 contents pages, 16 notes pages, 27 blank pages and one publisher back cover.

Engine, Powershift and Hydraulic Service

The following is a selection of covered work, rather than a complete contents list. Additional topics include operator-password management and European SIT tire replacement.

• Engine repair: GM V-6 and Perkins 1104 (RE) disassembly, internal inspection, timing, lubrication, valve-train work, compression diagnosis and cooling-system checks.

• Powershift drivetrain: Single- and two-speed clutch-pack, differential, MONOTROL® and control-valve repair; stall/pressure tests, inching/brake adjustment, neutral-start testing and two-speed shift diagnosis.

• Hydraulics and cylinders: Gear-pump overhaul, output and aeration checks, main control-valve repair, relief-valve adjustment, lift/tilt cylinder service, leak checks and mast-tilt adjustment.

• Brakes and steering: Brake-shoe, booster/master-cylinder and parking-brake service; steering-column, control-unit, axle, hub, spindle and steering-cylinder repair, with bleeding procedures and switch tests.

• ECM and electrical diagnosis: Spectrum fault-code charts, live data and actuator tests, LPG/gasoline component diagnosis, HVS ignition service, harness repair, Operator Presence System checks and alternator testing.

• Drawings and service data: Electrical/hydraulic schematics, sectional views, oil-flow diagrams, troubleshooting charts, torque data, pressure-test specifications, capacities, wear limits, clearances and adjustment values.

• Frame, cab and maintenance: Frame and cab component repair, power-unit removal, scheduled inspection and lubrication, lift-chain adjustment, leak checks, and wheel/tire service.

The depth of the internal engine and transmission procedures, along with the required lifting, hydraulic-test, electrical-test, and diagnostic equipment, makes this set best suited to trained lift-truck technicians and properly equipped repair shops.

GM and Perkins Engine Work

The engine sections provide step-by-step instructions for cylinder-head and block inspection, piston and connecting-rod service, and crankshaft repair. GM coverage includes timing components, lubrication and compression checks, with separate treatment of adjustable early valve trains and later zero-lash hydraulic lifters.

Perkins coverage extends to the timing case and gears, coolant pump, alternator and starter. Bosch EPVE injection-pump removal, installation and timing are covered; internal pump repairs are referred to an authorized repair station.

Specified tools include the Perkins PD.1D valve-guide tool, PD.170 timing-cover seal tool and PD.6118B valve-spring compressor. The Perkins section warns that leaving timing pins installed when refitting the timing cover can damage the engine.

Fuel Controls, Spectrum Diagnostics and Ignition

The shared fuel and ECM sections distinguish 3.0L throttle-body injection from 4.3L multi-point injection. For the H3.50-5.50XM models, the relevant GM application is the 4.3L; the 3.0L material applies to other trucks listed in those sections.

Component-replacement and diagnostic coverage includes the low-pressure lock-off and regulator, pressure- and fuel-trim valves, TMAP sensor, throttle body, mixer, fuel rail and injectors, supported by leak tests and symptom charts.

Spectrum procedures cover DTC reading and clearing through the malfunction indicator lamp or diagnostic software, sensor/actuator monitoring, ignition and injector tests, and throttle tests. Graphing and data logging support intermittent-fault diagnosis. Laptop procedures use separately sourced Diagnostic Software P/N 2067944 and Spectrum Special Tools Kit P/N 2067935.

HVS coverage includes distributor, crankshaft/camshaft sensor, ignition-coil and ignition-control-module service, plus connector and harness repair. Named tools include the OTC 7230 spark tester and KMJ35616A connector test adapter. The alternator section adds disassembly and reassembly, with brush, diode, rotor, stator and voltage-regulator checks.

Powershift Variants and Installation

The two-speed material distinguishes Exedy and non-Exedy clutch assemblies, older and newer pressure-plate arrangements, and differential setup with or without the original shim pack. Oil-flow diagrams trace neutral, forward, reverse, inching and range operation.

The Powershift sections specifically warn that incorrect torque-converter engagement during installation can damage the transmission oil pump.

Frame, Cab and Cooling Components

Frame procedures cover the counterweight, hood, overhead guard, operator restraint, radiator, exhaust, power-unit removal, and fuel/hydraulic tank repair. Cab work includes switch and fuse panels, wipers, heater and windows.

Cooling-system material includes radiator and exhaust-gas leak checks, thermostat testing, coolant draining/filling, and fan, belt and drive-shaft service.

Wiring Variants and Circuit References

The dedicated diagram section contains 16 numbered electrical and hydraulic references. Engine drawings include the Perkins Diesel Engine Electrical Schematic (1004-42), Perkins Diesel Engine Electrical Schematic (1104-44), and GM V-6 Gas and LPG Engine Electrical Schematic (L005).

L005 Powershift Operator Compartment Electrical Schematics are split before and after November 2005, helping technicians select the matching circuit before tracing a fault. The Hydraulic System Schematic and Hydrostatic Transmission Hydraulic Schematic cover the corresponding fluid circuits.

Follow the manual's blocking, lifting, hydraulic-pressure, brake, fuel-system, and electrical-isolation precautions before beginning service.

Valve-Clearance and Transmission-Pressure Examples

Perkins 1104 (RE) valve-adjustment data specify cold clearances of 0.20 mm (0.008 in.) at the inlet and 0.45 mm (0.018 in.) at the exhaust, measured between the valve stem and rocker arm.

For single-speed Powershift pump checks, test port 1 is specified at 1310–1476 kPa (190–214 psi), with the engine at 2000 rpm and transmission oil at 65–70°C (150–160°F). The same section provides test-port identification and pressure-fault charts.