Doosan GC15S-9 GC18S-9 GC20SC-9 Forklift Service Manual SB4483E00

Description

Doosan GC15S-9 GC18S-9 GC20SC-9 Forklift Service Manual – SB4483E00

This is the full Doosan service manual published for the GC15S-9, GC18S-9 and GC20SC-9 LP-gas forklift trucks. Document number SB4483E00, released March 2019 by Doosan Corporation Industrial Vehicle. It is the workshop-level reference used for disassembly, assembly, inspection, adjustment, pressure testing and troubleshooting across every major system on these three lift trucks.

If you maintain, rebuild or repair a GC15S-9, GC18S-9 or GC20SC-9, this Doosan service manual gives you the actual procedures and the actual numbers – not generic advice. Every chapter is built around the way the truck is assembled, so you can pull a component apart in the correct order, measure what matters, and put it back together to specification.

File Details

• Manual type: Vehicle Service Manual (workshop / repair)
• Brand: Doosan
• Manufacturer: Doosan Corporation Industrial Vehicle
• Models covered: GC15S-9, GC18S-9, GC20SC-9
• Document number: SB4483E00
• Publication date: March 2019
• Language: English
• Page count: 347 pages
• File format: PDF

Chapters Covered in This Doosan Forklift Service Manual

• 1 General – How to use this manual, warning label definitions, major units in use, glossary, exterior and specifications, safety precautions, maintenance intervals, lubricants (LP fuel specifications, recommended viscosities and capacities, lubricant specifications), disassembly/assembly instructions, standard torques for bolts, nuts and fittings
• 2 Transmission – Powertrain components, transmission components and specifications, hydraulic operations, oil and filter change, converter stall test, transmission pressure testing, inching adjustment, transmission removal/installation, engine removal/installation, transmission body disassembly/assembly, transmission housing, stator hub assembly, charge PTO driven gear, main PTO driven gear, main output gear, clutch assemblies, transmission case assembly, control valve assembly, troubleshooting
• 3 Drive Axle – Axle components and specifications, oil and filter change, drive wheel removal/installation, drive axle removal/installation, wheel hub and propeller shaft removal/installation, axle housing assembly, differential carrier assembly, differential assembly, brake piston assembly, brake block assembly, wheel hub assembly, wheel hub sub-assembly, carrier No. 2 assembly, troubleshooting
• 4 Hydraulic System – Components and oil flow, main hydraulic pump exterior, specifications, operation, removal and installation, priority valve exterior, specifications, operation, removal and installation, hydraulic tank and filter, suction strainer, return filter and air breather replacement, troubleshooting
• 5 Lift / Tilt / Auxiliary System – Components and oil flow, control valve exterior and specifications, control valve operation, relief valve adjustment, needle valve for emergent lowering, control valve removal/installation and disassembly/assembly, mast assembly exterior and specifications, mast operation, forks service, sideshifter service, chains service, tilt cylinders service, primary lift cylinders service, standard/secondary cylinders service, carriage service, mast service, troubleshooting
• 6 Steering System – Components and oil flow, steering control group, steering system air removal, steering system pressure check, steering wheel removal/installation, steering column assembly, steering unit, steering operation group, rear wheel turning angle adjustments, rear wheel and hub removal/installation/adjustment, steer axle, link assembly and steering cylinder, steering cylinder disassembly/assembly, steering knuckle, king pin and bearing, troubleshooting
• 7 Brake System – Components, hydraulic and mechanical operations, pedal group exterior and specifications, brake pedal group adjustments, removal and installation, disassembly and assembly, master cylinder exterior and specifications, air bleeding, removal and installation, brake block exterior and specifications, parking brake test, manual release of parking brake, removal and installation, service brake and parking brake troubleshooting
• 8 Frame / Miscellaneous – Hood removal/installation, floor plate removal/installation, FCU cover removal/installation, side cover, radiator cover and step cover, overhead guard, counterweight, instrument panel exterior and specifications, function descriptions, automatic shift controller (ASC) exterior, specifications, operation, settings, diagnostic function, removal and installation
• 9 Schematics – Powertrain hydraulic schematic, vehicle hydraulic schematic, electrical schematic

What makes this manual genuinely useful is the level at which the Doosan GC15S-9 GC18S-9 GC20SC-9 service manual operates. It does not stop at describing what a component does – it walks through the sequence for getting it out of the truck, lists the sealants and thread lockers used at each joint, states the tightening torque for the fasteners, and gives the measurement or pressure value that tells you whether the part is still serviceable. The transmission chapter alone covers converter stall testing, pressure testing at each port, and inching pedal adjustment against a stroke-versus-pressure graph. The drive axle chapter covers shimming calculations for axle shaft clearance and brake clearance checks. The mast chapter covers chain wear percentage measurement, carriage roller shimming with undersize/standard/oversize bearing options, and drift test limits for both tilt and lift cylinders.

Engine and Powerplant Coverage

The GC15S-9, GC18S-9 and GC20SC-9 are LP-gas trucks built around the PSI/4G63 engine – four cylinders, 1,997 cc displacement, rated 50.6 hp (37.7 kW) at 2,450 rpm with 110 ft lbs (148.7 Nm) of torque at 1,800 rpm. The manual covers the LP fuel system side of the powertrain through the lubrication and maintenance chapters, including LP fuel specifications and the recommended HD5/HD10 composition, LP regulator/converter inspection, mixer assembly, throttle assembly and fuel line checks at their scheduled intervals. The transmission and torque converter are treated in full, including the shared transmission/drive axle hydraulic circuit that circulates one oil supply through both components.

Specifications You Can Work From

The specification chapter of this Doosan forklift service manual covers the three models side by side, which matters because the capacity and weight figures differ between them. Load capacity runs 3,000 lb (1,340 kg) for the GC15S-9, 3,500 lb (1,560 kg) for the GC18S-9 and 4,000 lb (1,785 kg) for the GC20SC-9, with service weights of 6,038 lb (2,739 kg), 6,460 lb (2,930 kg) and 6,903 lb (3,131 kg) respectively. Lift height, free lift, mast lowered and extended heights, overall length, turning radius, travel speed, lift and lowering speeds, drawbar pull and gradeability are all tabulated per model. Tire sizes, tread widths, wheelbase, ground clearance and aisle width are included so you can work from the same figures Doosan published.

Standard torque tables cover metric and inch fasteners separately, plus taperlock studs, O-ring face seal fittings, 37 degree flared and straight thread O-ring fittings, 45 degree flared and inverted flare fittings, air conditioning fittings, tapered pipe thread fittings and hose clamp band types. That single chapter removes most of the guesswork from reassembly.

Lubricants, Capacities and Service Intervals

The manual lists recommended viscosities against ambient temperature ranges for the engine crankcase, hydraulic and power steering system, transmission and drive axle housing, and the brake reservoir. Refill capacities are given for the 4G63 LP-gas engine crankcase with filter, cooling system with coolant recovery bottle, hydraulic system, powershift transmission plus drive axle, and the OCDB brake reservoir. Lubricant specifications cover engine oil API ratings, hydraulic oil classifications against ISO, AFNOR, DIN, Hagglunds Denison and Cincinnati standards, DEXRON III for the transmission and drive axle, multipurpose molybdenum grease with NLGI grades, and approved brake fluid brands.

Maintenance scheduling is laid out by interval – inspection when required, first 50 to 100 service hours or a week, every 250 service hours or monthly, every 500 service hours or 3 months, every 1,000 service hours or 6 months, every 1,500 service hours or 6 months, every 2,000 service hours or yearly, every 2,500 service hours or 15 months, and every 8,000 service hours or 48 months. Each interval names the items to check and the criteria or method to check them by, including wheel bolt torque sequence, carriage roller extrusion heights for STD, FFL and FFT masts, belt deflection, overhead guard bolt torque, mast chain abrasion testing with the wear rate formula and 15.88 mm chain pitch, fork inspection limits and coolant hose condition.

What This Doosan Service Manual Lets You Do

With the Doosan GC15S-9 GC18S-9 GC20SC-9 service manual SB4483E00 in front of you, you can strip and rebuild the powershift transmission down to the clutch packs, measure clutch disc clearance against the 1.11 to 1.95 mm specification, and reassemble with the correct Loctite numbers and torques. You can pull the drive axle, reset differential backlash to 0.1 to 0.2 mm, read the gear contact pattern against marking ink, calculate axle shaft shim thickness from the measurement formula, and verify brake clearance. You can rebuild the mast assembly, adjust chain tension on both STD and FFL/FFT configurations, shim carriage and mast roller bearings to zero clearance, and test tilt and lift cylinder drift against the published limits. You can diagnose a transmission that will not shift, a mast that will not lower, steering that needs too much effort, or a parking brake that will not release, using the pressure charts, diagnostic code tables and probable-cause checklists in the troubleshooting chapters.

Working from the correct procedure and the correct specification is the difference between a repair that holds and a comeback. Transmission pressure readings taken at the right port at the right engine speed, torque values applied to the right fastener in the right sequence, and clearances set to the numbers Doosan published are what keep these trucks running safely. The electrical schematics, powertrain hydraulic schematic and vehicle hydraulic schematic at the back of the manual let you trace a circuit or a pressure path rather than replacing parts until something works.

IMAGES PREVIEW

Delivery is instant. The PDF downloads immediately after payment – no shipping, no waiting for a parcel, no CD to lose. Read it on a laptop, tablet or phone in the workshop, print the pages you need for the job in front of you, and keep the rest on file. Whether you are servicing one GC15S-9 or running a fleet of GC18S-9 and GC20SC-9 trucks, this manual stays usable.