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

• Official JCB Service Manual, Publication No. 9803/3710-3, copyright 2004, supplied as a 610-page PDF set for the 526, 526S, 528-70, and 528S from machine SN 1182000.
• Covers two-stage boom removal, wear-pad renewal and shimming, cab and combined-tank removal, LMI fault diagnosis and calibration, and optional R-134a air-conditioning service.
• Details dual-lever and single-lever hydraulics through circuit schematics, pump flow and pressure tests, relief-valve checks, pump and control-valve repair, ram resealing, and SRS accumulator service.
• Breaks down the SS600 Synchro Shuttle and PS750/PS750 Mk III Powershift drivetrains, SD70 front and SD55 rear axles, clutch operation, diagnostic testing, fault tables, and engine/gearbox separation.
• Provides electrical fault-finding for both transmission types, plus fuse/relay data, harness repair, starting and charging tests, alternator and starter overhaul, earth-point views, and production wiring drawings.
• Treats service brakes, park brake, and hydrostatic steering with leakage diagnosis, bleeding, adjustment, caliper repair, pressure testing, road-wheel re-phasing, proximity-switch setting, and steer-unit service.

This is workshop-level material, not an operator's guide. JCB designed the publication for distributor service engineers who have received technical training and already understand workshop practice, safety procedures, and hydraulic-equipment repair. It is suited to technicians with comparable knowledge and the required lifting, hydraulic-test, and electrical equipment.

Machine Identification and Build Variants

Coverage begins at machine SN 1182000. The VIN/PIN pages decode the 526, 526 USA, 528-70, and 528S model identifiers, SA naturally aspirated, SB turbocharged, and SC turbo-intercooled JCB Dieselmax build codes, plus three-, four-, and five-speed gearbox codes. Identification locations are shown for the machine, engine, Synchro Shuttle gearbox, and both axles. The transmission data also separates the PS750 from the PS750 Mk III by housing features and its transmission serial range (449/1305/01/0001 through 449/1323/01/0001, inclusive).

Diagnostics, Drawings, and Shop Data

The LMI chapter supplies fault-code tables, display-box and axle-transducer tests, harness continuity and short-circuit checks, dedicated 526 and 528 calibration charts, and use of test box 892/00905. Hydraulic circuit descriptions cover neutral, boom lift/lower, extension/retraction, hose-burst protection, parallel lift, relief valves, and SRS before moving into contamination control, pressure/flow diagnosis, component disassembly, inspection, assembly, and sealing work.

Named production drawings include Engine CAD 721/11835, the Synchro/Powershift Panel/Cab pair 721/11875 and 721/11877, the 526/528 Chassis pair 721/11874 and 721/11876, Synchro Shuttle CAD 721/10929, Powershift CAD 721/11669, and SRS CAD 721/11117 and 721/11118. Connector tables and harness destinations support the schematics. Tool references identify hydraulic pressure-test kit 892/00253, torque-converter alignment tool 892/00893, ram-seal fitting tool 892/00334, and engine lifting-bracket kit 320/20050.

Routine-maintenance coverage spans service schedules, filtration, cooling and fuel-system care, fluid selections and capacities, and final functional checks. Shop data covers UNF Grade S and Metric Grades 8.8, 10.9, and 12.9, Dacromet versus zinc-plated conditions, BSP/SAE and Torque Stop hydraulic connections, component torque tables, pressure and flow specifications, stall-speed data, wear limits, clearances, and electrical test values.

Repair Cautions and Scope Limits

The manual flags two easy-to-miss assembly hazards: the dimpled control-valve tie rod has a specified position to prevent early valve-block failure, while an incorrectly seated torque converter can damage the gearbox oil pump at startup.

Section K covers JCB 444 SA/SB specifications, cold-start electrical operation, cooling-pack removal, and complete engine removal/replacement. Internal engine overhaul procedures are not in this set; JCB points to Engine Service Manual 9806/3000 for full engine data and further engine service information. The SD70/SD55 axle and SS600/PS750 chapters provide identification, operation, fault finding, tests, and machine removal/replacement; internal axle and gearbox work, along with service-brake axle dismantling, refers to separate Transmissions Service Manual 9803/8610. Park-brake caliper dismantling, inspection, assembly, and repair are contained in this set.

This 12-file PDF set contains the main cover plus Sections 1, 2, 3, A, B, C, E, F, G, H, and K. Although the front index lists Section D - Controls, no separate Section D PDF is included.

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.