1990–2002 Valtra Valmet Tractors Mega Mezzo Hi-Tec Workshop Service Manual (P/N 39 210 211)

• Coverage and document identity: A 1,361-page English PDF of the Valtra Inc. Service Manual, Order no. 39 210 211, incorporating the listed update supplements through September 1, 2002.
• Engine repair: Covers 320, 420, 620, and 634 engine families in three-, four-, and six-cylinder form, including E low-emission builds, internal overhaul work, turbocharger service, engine removal and installation, and Bosch in-line and Stanadyne fuel-system procedures.
• Transmission and PTO work: Details tractor splitting, dry-clutch and Hi-Trol service, gearbox disassembly and setup, two-step quick-shift and Delta Powershift repair, mechanical and HiTech shuttles, 4WD clutch work, and rear/front PTO overhaul.
• Hydraulic, steering, brake, and axle service: Includes low- and high-pressure circuit testing, hydraulic pump and power-lift repair, steering leakage and valve checks, wet-brake service and bleeding, trailer air brakes, front-axle air suspension, and Sige and Carraro axle repair.
• Electronic controls and diagnosis: Addresses Autocontrol II, 2.1, 2.2/2.3, III, IV, 5, and 5.2; AC/ACB/ACD power lifts; self-diagnostics; fault codes; sensor, switch, and proportional-valve tests; and pedal, shuttle, DPS, PTO, and 4WD settings.
• Workshop reference material: Provides model- and serial-specific wiring diagrams, connector references, hydraulic schematics, fault-tracing charts, component views, numbered special tools, torque data, pressure-test specifications, capacities, tolerances, inspection limits, and adjustment data.

The title-page coverage includes 6000/6100/6200, 6250/6300/6350, 6400/6550/6600, 6650/6800/6850, 6900/8000/8100, 8200/8400/8050, 8150/8450/8550, 8750/8950, and 6600E-8750E tractors; later technical tables also identify 6750Hi and 8350Hi configurations. The manual covers Mega, Mezzo, E-model, and HiTech systems rather than treating the range as one mechanically identical tractor.

The source manual describes itself as a practical workshop reference and bases its repair instructions on normal workshop methods, with Valmet special tools where specified. It is therefore suited to professional tractor technicians and experienced repairers who can safely split a tractor, handle heavy assemblies, perform pressure and electrical tests, and select procedures by model and serial number.

Configuration and Diagnostic Detail

Serial and production breaks are built into the repair coverage. The clutch section separates Hi-Trol TD-VA units through serial 658205, Transfluid units from 658206 through 666065, and TD-FVA1 units from 666066. It also distinguishes the cable release mechanism from serial 659478 and the hydraulic release design from 668103. AC 5.2/HiTech 2.0 begins at K41107, while the Carraro 20.29 powered front axle replaced the earlier Sige industrial axle from production week 32/99.

Electrical coverage goes well beyond a basic schematic set. Main tractor wiring diagrams are separated for machines through serial 660070, 660071-662342, 662343-668102, and 668103 onward, with later HiTech diagrams broken out by build. E-model Autocontrol III and IV chapters include manual fault isolation and the original PC-based Service Program workflow; the Autocontrol IV procedure identifies RS-232C service cable 32668200. AC 5 and 5.2 use onboard test and setting modes for switches, temperature and speed sensors, proportional valves, clutch indexes, and prefill settings; AC 5.2 adds fault-code memory.

Schematics, Tools, and Repair Data

Named illustrations include the FieldMaster wiring diagram, AC 5.2 wiring and control diagrams, hydraulic diagrams for early, later, and HiTech circuits, the steering hydraulic diagram and fault-tracing chart, and the front PTO hydraulic circuit and wiring diagram. The drivetrain chapters add power-transmission servo/lubrication circuits and clutch, shuttle, differential, PTO, and axle section views.

Tool references are equally specific. Examples include clutch-disc centering tool ETV 893 790, Carraro bevel-pinion position tool set ETV 893 450, Carraro pinion-shaft nut socket ETV 893 490, and steering-valve seal tool ETV 893 100. A separate tools group also covers locally fabricated splitting supports and hydraulic pressure-measuring equipment.

Scope and Workshop Cautions

The Carraro section notes that earlier front wheel discs do not interchange with the 20.29 axle because its wheel-fixing studs differ. The electrical chapter warns that welding without isolating both battery cables and the alternator wiring can damage SigmaPower, CareTel, Agrodata, and Autocontrol electronics.

Maintenance schedules, lubricant and capacity tables, and service specifications are included, but the manual directs the reader to the separate Operator's Manual for detailed routine-maintenance instructions. The AC 5.2 section documents only the material that differs substantially from AC 5 and must be used with the referenced AC 5 pages.

Many procedures involve tractor splitting, heavy lifting, pressurized hydraulic or brake circuits, and refrigerant service. Follow the manual's support, pressure-test, electrical-isolation, and air-conditioning safety instructions and use equipment appropriate to the repair.