2001–2007 STILL R20 Electric Forklift Workshop Manual (P/N 171 085 - 01.06)

This STILL workshop manual covers service and repair of the 2001–2007 R20-15, R20-16, R20-17, and R20-20 electric forklifts. The English publication carries Ident. Nr. 171 085 - 01.06 [en], with a January 2006 revision date.

Text search, navigation, and diagram detail: Standard PDF text search is unavailable because of the document's character encoding, and there are no embedded bookmarks. Small schematic labels require zooming; some fine labels in the battery discharge indicator wiring diagram remain difficult to read.

• Drive unit repair: Motor and reduction-gear removal, bearing adjustments, brush inspection, commutator service, and motor insulation testing.

• Steering and brakes: Turntable and articulating steer axle service, Danfoss steering-unit checks, priority-valve cleaning, steering-cylinder rebuilding, and service and parking brake adjustments.

• Stilltronic electronics: SCR drive and pump controllers, thyodule testing, accelerator pedal transmitter adjustment, contactor servicing, and fail-safe circuit checks.

• Hydraulic service: Gear-pump replacement, control valve bank disassembly, pressure checks, return line filter maintenance, and anti-cavitation valve testing.

• Masts and fork carriage: Telescopic, Hi-Lo full free-lift, and Triple masts, with chain adjustment, roller clearance checks, and hoist and tilt cylinder repair.

• Diagnostic references: Drive and pump fault-isolation flowcharts, component resistance tables, electrical schematics, and illustrated test connections.

This manual is suited to forklift technicians familiar with electrical test equipment and equipped for press work and motor repair.

Drive Units, Steering Axles, and Brakes

The mechanical sections cover the chassis frame, overhead guard, and counterweight, followed by the twin drive motors and wheel reduction gears. Motor work extends to turning commutators on a lathe and undercutting mica; gearbox service includes pinion-bearing shim selection.

Motor tables distinguish the 24-volt GF 114-14/1.1 drive motor and GP 116-14/5.5 pump motor from the 48-volt GF 116-14/2.8 and GD 116-14/7.9 units.

Steering coverage separates the toothed-rack turntable from the articulating axle, including steering-cylinder mounting, turntable bearings, trail wheel hubs, and steering stops. The brake chapter distinguishes trucks with and without stop-light switches and describes brake-shoe relining.

Stilltronic Diagnostics and Electrical Variants

Both 24-volt and 48-volt systems are documented, including controller plug-in modules, current sensors, and main-circuit and control-circuit fuses. The R2007 configuration uses a shortened contactor panel and an Elektron battery discharge indicator with integrated electronics. Separate notes distinguish external and integrated pump-motor RPM sensors.

Drive and pump diagnostic flowcharts pair decision paths with illustrated test connections. Their component-specific readings help separate wiring, contactor, sensor, and power-stage faults before a circuit board is replaced.

Checks also address curve limit switches, thermal switches, and forced-ventilation fans. Test-equipment references include the STILL thyristor firing circuit 147803 and adapter cable 319806.

Contactor ventilation coverage distinguishes the serial breaks listed above and the long and shortened panel housings. Additional ventilation kit 383841 applies only to the long housing.

Uneven compression can crack a flat-pack thyristor. The mounting notes address this risk and explain why the pump-controller main thyristor cannot substitute for the drive-controller unit.

Hydraulic Control and Mast Repair

The steering sections identify the Danfoss OSPC 40 EL steering unit and OLSA 40 priority valve. Pressure checks and oil-flow descriptions explain how steering demand controls pump-motor operation.

Lift and tilt coverage includes mast-dependent restrictors, hoist-cylinder sealing, lowering valves, and line-failure safety devices. Fork-carriage support rollers, mast pivot shims, and tilt-cylinder reassembly receive separate treatment.

Incorrect clamping can distort a hoist-cylinder tube; the cylinder sections identify the vulnerable areas. Attachment pressure-regulator units I and II are covered, with attachment pressure limits governed by the attachment manufacturer's instructions.

Diagrams and Service Specifications

Illustrated references include Electrical Functions Inside the Power Unit, the Diagram Showing the Sequential Operation of Contactors, the Hydraulic Circuit Diagram, Oil Flow in Mast, and the Fork Arm Dimension Diagram. Exploded assemblies, component cross-sections, connector views, and terminal assignments support the repair material.

Reference data covers component-specific tightening torques, hydraulic pressure tests, lubrication and fluid capacities, brush wear limits, electrical resistance checks, and adjustment tolerances.

Follow the manual's precautions for battery isolation, stored capacitor energy, hydraulic pressure, and support of raised masts.

PDF Contents and Page Breakdown

One printable English PDF contains 246 pages: one cover page, 206 pages of workshop sections, and 39 pages of S-D test-equipment and diagnostic material. The cover and S-D section are already included in the total.