1993–2004 JCB 520, 520S, 526, 526S, 520-55 & 526-55 Loadall Telehandler Service Manual (P/N 9803/3610)

This 10th-issue JCB Loadall service manual, publication 9803/3610, covers the 1993–2004 520, 520S, 526, 526S, 520-55, and 526-55 telehandlers, including the documented RS, AWS, Farm Special, and Construction configurations.

• Transmission repair: Syncro Shuttle dismantling and assembly, Powershift clutch-pack overhaul and end-float adjustment, torque converter stall tests, and transmission troubleshooting.

• Axles and brakes: SD55 and SD70 axle service, differential and hub repair, brake leakage and pressure tests, bleeding, and parking-brake adjustment.

• Hydraulics and steering: Main pump testing and resealing, valve-block and cylinder service, hose-burst valve checks, steering-unit repair, and steering-system bleeding.

• Electrical diagnosis: Serial-specific wiring diagrams, connector pinouts, charging and starter tests, and ECU harness, solenoid, and speed-sensor checks.

• Load and ride systems: Safe Load Indicator (SLI) and Load Moment Indicator (LMI) calibration, transducer testing, diagnostic fault-code charts, and Smooth Ride System (SRS) troubleshooting.

• Body and engine service: Cab removal, direct glazing, fuel/hydraulic tank removal, boom wear-pad replacement, radiator service, and engine/transmission removal and separation.

• Service references: Maintenance schedules, VIN and unit identification, engine-specific lubricant and capacity tables, fastener torque data, sealing compounds, and illustrated service-tool listings.

JCB wrote this manual for distributor service engineers who are receiving or have completed JCB training and already understand workshop safety and hydraulic equipment service.

Transmission Builds and Axle Repairs

Separate SS640, PS700, and PS750 section views accompany the transmission procedures. Powershift instructions distinguish reverser-shaft cover-plate and sealing-plug housings, with different clutch procedures for PS700 and PS750.

The Powershift assembly instructions warn that pulling a misaligned rear casing into place with its bolts can damage the clutch plates.

SD55 coverage includes splined-hub service, limited-slip differential inspection, pinion-depth setting, and crown wheel/pinion backlash adjustment. Tool references include Hub Service Kit 892/01092 and Solid Spacer Setting Kit 892/00918.

Brake instructions distinguish the different hydraulic systems and warn that incorrect fluid can damage seals and cause brake failure.

ECU Diagnosis and Load Indicators

The Simplified ECU Installation diagram and Mark II handheld test unit 892/00943 instructions support electrical checks. Matching the serial-specific wiring to the fitted controls helps isolate harness, switch, or solenoid faults before a transmission is dismantled.

The LMI Diagnostic Fault Codes chart accompanies display and transducer tests using test box 892/00905. SLI and LMI display boxes are not interchangeable; North American machines are described as normally lacking these systems.

Hydraulic Circuits and Boom Service

Hydraulic schematics distinguish single- and dual-lever controls. The SRS Hydraulic System Diagram, Electrical Circuit Diagram, and harness layouts connect the accumulator, solenoid, and wiring information. Fault charts address ram creep and parallel-lift problems.

Main pump instructions distinguish external-leak resealing from low-output wear that calls for pump or pump-section replacement.

Before service procedures or heavy component lifting, technicians must verify all load-bearing supports and follow the manual's workshop safety precautions, including those for a raised boom.

Engine Maintenance and Air-Conditioning Scope

Maintenance and fluid tables distinguish AA, AB, AR, AK, RE, and RG engine builds. Fuel priming and filter procedures account for engine-family differences. General torque tables cover UNF Grade S and metric grade 8.8 bolts, with dry-thread values and a reduction instruction for lubricated threads.

Section K concentrates on engine specifications and removal work. For further engine details and injection-system service, it refers to separate publications 9806/0100 for AA/AB, 9806/2140 for AR/AK, and 9806/2250 for RE/RG. Those engine manuals are not included.

Air-conditioning coverage includes wiring, fault finding, leak testing, and component replacement. Refrigerant charging and discharging procedures are expressly excluded.

A Preview of Hub Torque and Transmission Test Data

These examples are a small selection of the bearing and pressure data in the manual.

The wheel-hub tool reference specifies bearing rolling torque of 12–22 Nm (9–16 lbf ft), excluding seal drag, with a maximum of 40 Nm (29.5 lbf ft) including seal drag.

For the Syncro Shuttle, the main-line pressure table lists 9.3–10.3 bar (135–150 lbf/in²) in neutral at 1,000 rpm and an oil temperature of 50°C.

Text Search, Diagram Detail, and PDF Contents

Search and navigation: Main text and tables are searchable, but some wiring-label numbers are not searchable text. Two bookmarks provide broad navigation only, without a chapter-by-chapter bookmark index. Small wiring and connector labels require zooming.

Supplied as one printable 586-page PDF: 583 section pages plus one title page, one introduction page, and one machine-history page. These three opening pages are already included in the total.