1976 Case 480C Backhoe Loader Service Manual (P/N 9-66025)

• Coverage: Case 480C loader/backhoe factory service material for the 188 and 207 diesel engine families, with chapter-level notes where coverage is limited to the 188 or to naturally aspirated machines.
• Document set: 761-page PDF — 753 pages of Case factory service-manual content, six digital cover/navigation pages, and a two-page 480 Construction King brochure. The base issue is C.E. Div. Form 9-66025, August 1976, with later factory revised sections retained.
• Engine and fuel repair: Diagnostic charts, tune-up and compression testing, cylinder-head and valve-train overhaul, 188 block/sleeve/piston work, crankshaft and bearing service, engine removal, cooling and lubrication, Roosa Master DB pump timing, injector testing, and fuel-system bleeding.
• Hydraulic repair: System troubleshooting, flowmeter and pressure checks, four hydraulic-pump makes, loader/backhoe/three-point valves, cylinders, extendable dipper, boom lock, relief valves, selector valve, and PTO motor.
• Powertrain and chassis: Shuttle controls, transaxle and differential lock, clutch and pressure plate, two-speed mechanical shuttle, drive shaft, steering system, front axle, and self-adjusting differential brakes.
• Electrical and mounted equipment: Charging/starting fault isolation, color-keyed wiring diagrams, instrument-cluster tests, starter and alternator repair, loader and backhoe removal/installation, three-point hitch, and ROPS, cab, and canopy inspection.

Factory Repair Coverage

Case organized this publication as a sectional shop manual. The engine scope changes by chapter: diagnosis, tune-up, cylinder head, valve train, camshaft, crankshaft, oil pump, cooling, lubrication, and engine removal address the 188 and 207 diesel families, while the cylinder block, sleeves, pistons, and rods section is specifically marked for the 188 diesel.

Engine diagnosis is arranged around actual complaints—hard starting or no-start, starts but will not run, misfire, knock, overheating, power loss, high oil consumption, and low oil pressure. The repair chapters cover compression checks, valve adjustment, head removal and reconditioning, and valve-guide and seat work. Separate procedures handle camshaft-bushing replacement, timing-gear setup, crankshaft and main-bearing inspection, oil-seal replacement, oil-pump service, engine and radiator removal, thermostat and water-pump work, and lubrication-system tracing.

Fuel-system coverage separates early and late filter arrangements and shows the related bleeding layouts. Roosa Master Model DB material covers pump removal, drive-gear backlash, installation and timing, governed-speed checks, injector identification, nozzle testing, adjustment, and servicing. The revised injector application chart distinguishes 188D, 207D, and 207DT nozzle applications.

Hydraulic, Drivetrain, and Equipment Systems

The main hydraulic section separates single-circuit faults from loader-only, backhoe/three-point, and all-circuit failures. It then provides flowmeter tests for pump output, main relief, loader and backhoe circuits, the PTO motor, secondary relief valves, boom-lock relief, and the pump-protection valve. Separate pump chapters cover Cessna, TRW, Dana, and Borg-Warner units through removal, disassembly, inspection, assembly, installation, break-in, and failure analysis.

Valve and cylinder repair is organized by machine configuration: loader, backhoe, and three-point-hitch control valves; dipper-extension and selector valves; two-stage main relief and pump-protection valves; boom lock; PTO motor; and loader, backhoe, swing, and stabilizer cylinders. Mounted-equipment chapters add loader-arm and bucket service, backhoe and swing-tower removal, dipper-extension components, boom-lock plumbing, and both hand-swing and foot-swing control layouts.

Powertrain coverage reaches into transaxle removal, final-drive and axle-housing work, and mainshaft and countershaft service. It also documents differential-center-wheel and side-gear rebuilding, backlash and bearing-preload setup, differential-lock repair, clutch and pressure-plate service, and two-speed mechanical-shuttle teardown and adjustment. Steering chapters include the hydraulic circuit, pressure checks, pump and control-valve repair, cylinders, front wheel bearings, king pins, and toe-in. Brake coverage includes pedals-to-transaxle linkage and the revised self-adjusting differential-brake assembly.

Schematics, Specifications, and Repair Notes

Named drawings include the Loader Hydraulic Diagram, Backhoe Hydraulic Diagram, Extendable Dipper Hydraulic Diagram, Power Steering Hydraulic Diagram, Cab Wiring Diagram, and PTO Tachometer Circuit. Factory photographs, sectional views, and exploded assembly drawings support the repair procedures. Electrical chapters add a wiring color key, charging- and starting-circuit troubleshooting, instrument-panel and cluster checks, battery service, starter/solenoid overhaul, alternator testing, and cab/canopy accessory installations.

Factory data covers maintenance intervals, approved fluids and capacities, general and component-specific torque tables, hydraulic fitting torques, and pressure and flow tests. Wear limits, clearances, injector specifications, electrical checks, and adjustment data are carried into the relevant component sections. Tool references include the M20322/Bacharach 65-934D test stand, M20520 compression-gauge adapter, A43278 injector removal tool, A43277 injector-bore cleaner, A43112 valve-guide reamer, and A40682 sleeve clamp bar, plus dimensions for shop-made tools.

Engine serial 2718490 separates the early and late diesel-filter layouts. Engine serial 2072089 changes rocker-arm oiling and rear camshaft-bushing details. Later Case inserts are retained, including December 1980 injector, transaxle/differential-lock, and self-adjusting-brake sections and a July 1980 two-speed-shuttle section; the revised drivetrain and brake material is marked for naturally aspirated machines.

The manual also flags repair traps that can ruin fresh work. After cylinder-head resurfacing, valve protrusion must be checked to prevent piston-to-valve contact. Incorrect placement of the rocker-arm oil-feed bolt or bushing can starve the shaft and rockers, while abrasive left after sleeve deglazing can score new parts and damage bearings.

Before lifting the engine or backhoe, working under a raised loader, opening hydraulic circuits, or testing diesel injectors, follow the factory support, pressure-release, and high-pressure fuel warnings. The appended brochure supplies period 480 Construction King specifications but remains separate from the repair procedures.