John Deere 675 & 675B Skid Steer Loader 1987–1994 Technical Manual (P/N TM1374)

• Covers John Deere 675 and 675B skid steer loaders, including the single-switch 675 seat circuit, deluxe-seat 675B configuration, operator-presence variants, and serial-specific wire-harness layouts.
• The PDF contains the 267-page John Deere technical publication TM1374 (September 1994) for the Yanmar 4TN82ESP-powered loader, with component repair procedures, specifications, operational checkout, and system diagnosis.
• Covers engine and radiator removal and installation, throttle-linkage adjustment, fuel-transfer-pump testing, fuel shutoff and tank/sender repair, cooling-system testing, compression checks, oil-pressure testing, and injection-pump timing inspection.
• Details hydrostatic pump and motor teardown and assembly, back-plate and needle-bearing service, drive-chain, idler, axle, and spring-dampener repair, steering-neutralizer overhaul, park-brake adjustment, and pump/motor efficiency testing.
• Includes hydraulic charge-pump, main and auxiliary control-valve, cylinder, boom-lockout, relief-valve, and charge-check-valve repair, plus wiring diagrams, component locations, pressure and flow tests, cycle-time checks, and boom/bucket drift diagnosis.

Technical Content & Workshop Utility

TM1374 is organized as a machine-level workshop manual for the Yanmar 4TN82ESP four-cylinder diesel, hydrostatic drive, Cessna gear-type implement pump, final-drive chains, and loader hydraulic system used in the covered 675-series machines. Its repair sections are paired with separate operational-checkout and diagnosis sections, so the publication supports both component work and fault isolation instead of treating the loader as a collection of routine maintenance items.

The engine section covers removal and installation of the complete engine, inspection of the engine mounts, spring-dampener spline preparation, alignment with the hydrostatic pump, and radiator removal, inspection, and installation. Fuel and air coverage includes throttle-control linkage inspection and adjustment, fuel-transfer-pump pressure and delivery testing, fuel shutoff solenoid replacement, fuel-tank removal and inspection, fuel-gauge sending-unit service, and fuel-system bleeding. The engine/fuel diagnostic section adds cooling-system pressure testing, compression testing, engine-oil-pressure checks, injection-pump timing inspection, idle-speed adjustment, and structured diagnosis for starting, performance, temperature, and fuel-delivery complaints.

Power-train coverage goes well beyond external adjustments. The manual takes the tandem hydrostatic pumps through removal, separation, internal disassembly, back-plate service, component inspection, needle-bearing replacement, assembly, joining, installation, and the required start-up procedure after pump or motor repair. The hydrostatic motor receives comparable teardown, inspection, and assembly coverage. Final-drive work includes chain and idler removal, drive-gear and axle service, chain-case access, drive-chain installation and tension adjustment, post-repair start-up checks, and a winching procedure. Steering and brake sections address park-brake inspection and adjustment along with steering-neutralizer removal, overhaul, installation, and final adjustment.

Hydraulic repair procedures cover the charge pump, main control valve, diverter and auxiliary valves, lift-arm and bucket cylinders, oil cooler, boom-lockout solenoid valve, boom relief valve, charge check valve, lift arms, and mechanical stops. The related test section provides system and boom-relief pressure testing, hydraulic-pump flow testing, boom cycle-time measurement, and diagnostic checks for weak lift, bucket rollback or dump problems, float operation, boom lockout, cylinder drift, and the mechanical lift-arm lock.

Specification and Reference Data

The electrical coverage is divided by machine configuration rather than presented as one generic circuit. TM1374 identifies the single-switch 675 seat arrangement for S/N 380001–475000 and the deluxe-seat 675B arrangement beginning at S/N 475001. Later diagnostic material covers battery, starting, charging, preheat, fuel-shutoff, seat-lockout, boom-lockout, and operator-presence circuits. Separate 675B operator-presence schematics address rectangular- and round-connector systems, and serial-specific harness drawings help match the test path to the machine before wires or switches are replaced.

Useful visual references include the labeled throttle-control linkage drawing, hydrostatic-pump internal component view, chain-case cross section, electrical component-location drawing, 675 system and optional-equipment schematics, and 675B rectangular- and round-connector operator-presence diagrams. These are supported by checkout charts and symptom-based diagnostic sequences for engine, electrical, power-train, and hydraulic faults.

Factory tool callouts include the JDG-356 fuel-pump pressure test kit, JTO1674 compression test kit with JDG560 adapter, JDG282 hydraulic-oil temperature gauge, and John Deere pressure-gauge and Flowrater setups for charge-pressure, relief-pressure, pump-flow, and efficiency testing. Reference data includes component-specific torque tables, pressure and flow specifications, capacities and approved fluids, clearances, inspection limits, adjustment data, and electrical test values.

Several details matter during repair. The chain case also serves as the hydraulic reservoir, so metal debris or weld spatter left after chain-case damage can circulate into hydraulic components. The hydrostatic-motor back plate must not be forced onto the housing; failure to seat indicates internal misalignment. Main-control-valve spools are matched to the valve body, and paint or corrosion on an exposed spool can damage internal porting during removal.

Before service, lower attachments or support raised lift arms on the factory stops and relieve hydraulic pressure before opening any line. TM1374 covers machine-level engine removal, installation, testing, and diagnosis, but it is not a complete internal Yanmar engine overhaul manual. Internal engine work and starter, alternator, and voltage-regulator repair are referred to Yanmar component technical manual CTM-3.