JCB 526, 526S, 528-70 & 528S Telehandler Service Manual, 2004–2010 (P/N 9803/3710-3)

JCB Service Manual, P/N 9803/3710-3, copyright 2004, covers the 526, 526S, 528-70, and 528S from machine SN 1182000.

Text Search, Bookmarks and Diagram Detail

Search and navigation: The section files contain searchable text, although some electrical diagram labels are not reliably searchable. Each PDF has two generic part bookmarks rather than topic-by-topic bookmarks. Small schematic labels require enlargement; some hydraulic drawings have light, fine lines at fit-to-page size.

The ZIP contains 610 pages across 12 printable PDFs: the two-page main cover/index file and 608 pages in Sections 1, 2, 3, A, B, C, E, F, G, H, and K. The total includes 12 main/section cover pages and 24 notes or otherwise blank pages, including two unused contents pages. Section files carry mixed revision markings. Section D—Controls appears in the front index but is not supplied.

Boom, Hydraulic and Drivetrain Service

The following is a selection of covered work. Other topics include attachment quick-release couplings and direct-glazed cab windows.

• Boom and framework: Two-stage boom removal, wear-pad renewal and shimming, cab removal, and separate combined fuel/hydraulic tank removal procedures for the machine families.

• Load Moment Indicator: Fault-code tables, display-box and axle-transducer tests, harness checks, calibration procedures, and dedicated calibration charts.

• Hydraulics: Dual-lever and single-lever circuits, pump flow and relief-valve tests, control-valve service, hydraulic ram resealing, and Smooth Ride System service.

• Drivetrain: SS600 Synchro Shuttle and PS750/PS750 Mk III operation, stall and pressure tests, SD70/SD55 axle service, and engine/gearbox separation.

• Electrical diagnosis: Transmission-specific schematics, fuse and relay data, starting and charging tests, harness repair, ground-point views, and alternator/starter removal and replacement.

• Brakes and steering: Leakage diagnosis, bleeding, park-brake adjustment and caliper repair, steering pressure tests, wheel re-phasing, proximity-switch setting, and steering-unit service.

• Engine and cooling: JCB 444 SA/SB specifications, cold-start electrical operation, cooling-pack removal, and complete engine removal and replacement.

JCB designed this publication for distributor service engineers receiving or having completed technical training. It assumes sound workshop practice, safety knowledge, and experience with hydraulic-equipment maintenance and repair, with suitable lifting, hydraulic-test, and electrical equipment available.

LMI Diagnosis and Cab Air Conditioning

The LMI chapter separates display-box, axle-transducer, and machine-harness faults through functional tests, continuity checks, and short-circuit tests. It documents test box 892/00905 and separate 526 and 528 calibration charts, allowing the calibration procedure to be matched to the machine family.

Optional R-134a air-conditioning coverage includes gauge-based diagnosis, leak testing, refrigerant recovery, evacuation and charging, binary pressure-switch testing, and HVAC component replacement.

Hydraulic Circuits and Component Repair

Circuit descriptions explain neutral flow, boom lift/lower, extension/retraction, hose-burst protection, parallel lift, relief valves, and SRS operation. The pump-flow test helps distinguish a pump supply fault from a steering- or service-circuit problem.

Step-by-step procedures cover control-valve dismantling and hydraulic ram sealing, with separate removal sections for the lift, displacement, extension, and tilt rams. Tool references include pressure-test kit 892/00253 and ram-seal fitting tool 892/00334.

Main-pump dismantling is for resealing a serviceable pump; inadequate output that cannot be corrected at the relief valve calls for complete pump replacement. The servo pilot pressure-reducing cartridge is limited to cleaning or complete replacement. SRS procedures cover accumulator charging, discharging, and replacement.

The dimpled control-valve tie rod has a specified assembly position; incorrect positioning can cause early valve-block failure.

Transmission, Axles and Brake Repair Limits

Transmission diagnosis covers clutch operation, solenoid identification, pressure and flow testing, clutch-leakage tests, and fault tables. Housing illustrations distinguish the PS750 from the PS750 Mk III.

SD70 front-axle and SD55 rear-axle procedures include seal work and machine removal/replacement. Internal axle and gearbox work, including service-brake axle dismantling, refers to the separate Transmissions Service Manual 9803/8610, which is not included.

Park-brake caliper dismantling, inspection, assembly, and repair are contained here. The brake master cylinder is replaced as a complete unit if faulty.

Torque-converter alignment tool 892/00893 is identified. An incorrectly seated converter can damage the gearbox oil pump at startup.

Electrical Drawings and Connector Data

Production drawings include Engine CAD 721/11835, Panel/Cab 721/11875 and 721/11877, and Chassis 721/11874 and 721/11876. Transmission drawings distinguish Synchro Shuttle 721/10929 from Powershift 721/11669; SRS drawings are 721/11117 and 721/11118.

Connector tables show wire connections and harness destinations. Ground-point views support fault tracing, while the starting and charging tests address circuit voltage, connections, and component performance.

Maintenance and Engine Service Scope

Routine-maintenance coverage includes service schedules, filtration, cooling and fuel-system care, fluid selections and capacities, and functional checks. Engine removal information identifies lifting-bracket kit 320/20050.

The engine section provides SA/SB specifications and complete engine installation work. Internal engine overhaul and alternator/starter dismantling refer to the separate Engine Service Manual 9806/3000, which is not included.

Reference data covers UNF Grade S and Metric Grades 8.8, 10.9, and 12.9 fasteners, Dacromet versus zinc-plated conditions, BSP/SAE and Torque Stop hydraulic connections, component torque tables, stall-speed data, wear limits, clearances, and electrical test values.

Workshop Safety

Safety coverage addresses raised-boom support, stored hydraulic pressure, heavy components, brake work, moving engine parts, electrical isolation, and pressurized R-134a refrigerant. Air-conditioning circuit work is reserved for appropriately trained personnel.

Selected Steering Pressure and Alignment Data

Steering specifications list a relief-valve operating pressure of 175 ± 3 bar at 1,500 rpm. The corresponding system-pressure test checks the reading at full steering lock.

For front- and rear-axle proximity-switch setup, the specified steering-ram reference dimension X is 129 mm with the wheels straight ahead.