CLARK GTS 20 25 30 33 L PSI 4G64 Forklift Service Manual – Book SM 1024

Description

CLARK GTS 20/25/30/33 L (PSI 4G64) Forklift Service Manual — Book SM 1024

This is the full CLARK service manual for the GTS 20, GTS 25, GTS 30 and GTS 33 L series forklift trucks running the PSI 4G64 LPG engine. Published as Book No. SM 1024, Revision 1.8, dated March 2020, Part No. 8129703, it is the same group-by-group reference used to maintain, diagnose and overhaul these trucks from the 2,000 kg GTS 20 up to the 3,300 kg GTS 33 L. The manual runs roughly 780 pages of procedures, exploded views, wiring and hydraulic schematics, torque values and diagnostic trouble code charts, organised under CLARK’s own Group numbering system (Group SA, PS, 00, 01, 03, 07, 13, 21, 22, 23, 25, 26, 29, 30, 32, 34, 38 and 40).

File Details

• Manual type: CLARK workshop-level service manual
• Brand / manufacturer: CLARK Material Handling
• Models covered: GTS 20, GTS 25, GTS 30, GTS 33 L
• Engine covered: PSI 4G64 LPG (with reference data for the 4G63)
• Document number: Part No. 8129703 / Book No. SM 1024
• Revision / date: Rev 1.8 — March 2020
• Language: English
• Format: PDF, instant download, printable on any device
• Length: approximately 780 pages

Chapters Covered

• Group SA — Safe Maintenance: safety signs and messages, safe parking, lifting, jacking, blocking and towing procedures
• Group PS — Periodic Service: maintenance schedules, lubrication points, planned maintenance program
• Group 00 — Engine (LPG PSI 4G64): general information, timing belt, water pump, rocker arms and camshaft, cylinder head and valves, front case / silent shaft / oil pan, piston and connecting rod, crankshaft and cylinder block, compression test, maintenance, LPG fuel system, gasoline fuel system, emissions control, electrical section, diagnostic scan tool (DST), engine wire harness repair, diagnostic trouble codes, definitions
• Group 01 — Cooling System: specifications, troubleshooting, testing, belt service, radiator removal and replacement
• Group 03 — Intake and Exhaust System: air cleaner service, exhaust manifold and water pump removal
• Group 07 — Transmission: structure and functions, disassembly and assembly, maintenance, troubleshooting and repair
• Group 13 — Electrical System: circuit diagram and electrical parts arrangement, instrument panel, component specifications and operation
• Group 21 — Drive Axle: carrier assembly, differential, disassembly and assembly, lubrication, troubleshooting
• Group 22 — Wheels and Tires: pneumatic wheels and tires, tire maintenance, inflation, mounting procedures
• Group 23 — Brake System: braking and inching specifications, troubleshooting, pedal adjustment, brake bleeding, master cylinder service, parking brake
• Group 25 — Steering Column and Gear: specifications, troubleshooting, component removal, relief pressure check and adjustment, steering gear overhaul
• Group 26 — Steer Axle: wheel bearing adjustment, steer axle overhaul, steer cylinder removal and overhaul
• Group 29 — Hydraulic Pump, Sump and Filters: sump, filters, main hydraulic pump troubleshooting, removal, and Jinsung pump overhaul
• Group 30 — Hydraulic Control Valve / Lift Circuit: specifications, schematics, troubleshooting, pressure checks and adjustment, valve removal, valve overhaul
• Group 32 — Tilt Cylinders: specifications, racking and drift checks, removal, overhaul
• Group 34 — Upright: specifications, troubleshooting, inspection, roller shimming, cylinder removal and overhaul, chain inspection and replacement, fork and carriage removal, upright removal
• Group 38 — Counterweight and Chassis: counterweight removal and replacement, overhead guard, operator’s cell, floorboard, cowls, seat deck
• Group 40 — Specifications: nameplates and decals, general truck specifications, hydraulic fitting tightening procedures

The CLARK GTS service manual is laid out so a technician can move from a symptom straight to the system that produces it. Each Group opens with its own specifications, then troubleshooting, then the service procedures, then overhaul instructions for the assemblies that wear out. That sequencing is what makes the book usable in a working shop: diagnose against the symptom table, confirm against the pressure and clearance values, then rebuild to the torque figures listed in the same section. The Group SA safe maintenance section is included up front because these trucks carry loads up to 3,300 kg — the jacking, blocking and towing procedures are not optional extras, they are the first thing a technician needs before any major component comes off.

PSI 4G64 Engine and LPG Fuel System Coverage

The engine section is the deepest part of the CLARK GTS 20 25 30 33 L PSI 4G64 service manual. It goes well beyond a tune-up: cylinder head removal and valve servicing with the correct torque-and-angle sequence, camshaft and rocker arm inspection, timing belt replacement with the balance shaft belt, front case and silent shaft service, piston and connecting rod removal with the piston pin setting tool, crankshaft and cylinder block measurement, and the full compression test procedure. The LPG fuel system is documented from the schematic through to the Direct Electronic Pressure Regulator (DEPR), air valve mixer, light duty 2-stage vaporizer, electronic throttle control, three-way catalytic converter and the heated exhaust gas oxygen sensors. Diagnostic trouble codes are listed in full — sorted both by DTC number and by SPN:FMI — with conditions for setting the code and step-by-step diagnostic charts for the fault conditions a technician is most likely to hit. The Diagnostic Scan Tool (DST) section explains installation, connecting to the ECM, password entry, raw volts pages, service pages, tests page (spark kill, injector kill, DBW test), faults page, and the plot/log snapshot functions. There is also a blink code function documented for both the GCP and 4G controllers when a laptop is not available.

Hydraulics, Transmission, Brakes and Upright

The rest of the CLARK GTS 20 25 30 33 L PSI 4G64 manual is just as deep. Transmission coverage includes the torque converter, control valve, clutch shaft, power flow charts, disassembly and reassembly with the Loctite numbers and torque values, oil change cycle and clutch pressure specs. The drive axle section covers the carrier assembly, differential, planetary reduction gear, wet disc brakes, shimming the pinion, backlash adjustment and contact pattern checking. The upright section is one of the most detailed parts of the book — roller clearance charts, side clearance checks with the spanner tool, shim adjustment, carriage roller shimming, chain inspection (elongation, edge wear, turned pins, cracked plates), chain length adjustment for standard, TSU and Hi-Lo uprights, and full cylinder overhaul with the correct gland torque values. Hydraulic control valve coverage includes the flow control adjustments, main and auxiliary relief pressures, and the exploded view of the valve sections.

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Instant PDF Delivery — Why Technicians Keep It On Hand

This CLARK GTS 20/25/30/33 L (PSI 4G64) service manual gives a technician everything needed to run scheduled maintenance, diagnose a fault, or rebuild a major assembly on the GTS 20, GTS 25, GTS 30 and GTS 33 L trucks without guesswork. The correct torque sequences, clearance values, relief pressures, drift limits and DTC flow charts are all in one place — which is exactly why it matters when a truck is down and a wrong specification costs time and parts. Delivered as an instant PDF download after payment, no shipping, no waiting, printable from any device in the workshop.