1979 John Deere JD500-C Backhoe Loader Technical Manual (P/N TM-1038)

John Deere technical manual TM-1038 covers service and repair of the 1979 JD500-C Loader Backhoe, including collar-shift and power-shift configurations. The October 1979 issue includes revised pages dated December 1980. Its eight sections cover predelivery checks, lubrication, diagnosis, and component repair.

• Engine and fuel system: Internal engine repair, engine balancer service, cooling and lubrication diagnosis, plus Roosa-Master JDB injection-pump removal, installation, and timing.

• Power train: Collar-shift and power-shift transmission repair, engine disconnect clutch service, both PTO types, planetary gear-pack overhaul, and differential adjustments.

• Hydraulic diagnosis: Master hydraulic system analyzer tests, pump checks, function and cylinder leakage tests, and pressure-control and differential-lock valve diagnosis.

• Steering and brakes: Serial-specific steering-valve repair, steering-system bleeding, power-brake service, and brake accumulator testing.

• Electrical system: Wiring diagrams, harness connector views, charging-circuit tests, and Delco-Remy and John Deere starting-motor repair.

• Loader and backhoe: 9500 and 9705 backhoe components, loader control valves, hydraulic cylinders, Drott 4-in-1 bucket, extendible dipperstick, and front axle pivot bracket repair.

John Deere wrote this manual for experienced service technicians; basic theory and training are covered in separate Fundamentals of Service manuals.

Engine Repair and Injection-Pump Coverage

Separation procedures cover removal and installation of the backhoe, loader, engine, clutch housing, and final drives. Internal engine coverage extends to liners, pistons, crankshaft components, and the balancer assembly, with the staged cylinder-head tightening sequence and subsequent run-in checks.

Roosa-Master JDB coverage includes on-engine diagnosis, drive-shaft inspection, static timing, and cam-advance adjustment. Internal injection-pump and nozzle service is referred to the separate SM-2045 manual, which is not included. The tool lists identify the JD259 timing window and JD256 drive-shaft seal compressing tool.

The pump-installation notes warn that forcing a drive-shaft seal backward can damage it.

Transmission Tests and Gear Setup

Power-shift pressure and drag tests help distinguish hydraulic control faults from excessive drag in clutch or brake packs. The Clutch and Brake Engagement chart shows which elements operate in each gear.

Repair coverage includes the oil pressure regulating valve. Reduction-gear setup combines backlash measurements with tooth bearing pattern illustrations, while differential adjustment specifies bearing preload.

Hydraulic Fault Isolation and Steering Variants

The analyzer section uses a symptom index to organize tests for pump supply, function leakage, cylinder leakage, and brake and differential-lock valves. These tests help separate inadequate pump output from internal leakage. A Circuit Flow Diagram shows how the hydraulic functions connect, and the JD-293 transmission pump tool kit has a dedicated test method.

Steering coverage separates earlier piston-type arrangements from later gerotor valves. The early system includes synchronizing-valve diagnosis. Hydraulic oil accumulator and brake accumulator service are treated separately.

Raised loader arms, heavy assemblies, and pressurized accumulators require the support and pressure-release precautions described in the manual.

Backhoe Cylinders and Attachment Repair

The 9500 backhoe has dedicated rotary swing-cylinder repair coverage and a Swing Cylinder Hydraulic Brake Operation diagram. The 9705 swing cylinder has its own assembly view.

Extendible-dipperstick procedures cover cylinder removal, inspection, and reassembly. A specific caution explains how pipe-wrench damage to the cylinder rod can also damage bearings and chevron packing.

Wiring Layouts and Connector Identification

Separate electrical schematics and wire-routing information cover the serial-number break at 255480. Instrument Harness Connector and Accessories Harness Connector views identify terminal positions, wire colors, and destinations, helping match the wiring to the machine before circuit testing.

Examples from the Pump and Cooling Specifications

These entries are a small sample of the manual's service specifications. The unit tune-up chart lists power-shift transmission-pump flow at 10 gpm at 1900 rpm; the dedicated diagnostic sections provide their individual test setups and conditions.

Cooling-system data include a 19-qt. capacity and a water-pump impeller-to-housing seat clearance of 0.015–0.035 in. Related tables provide component wear limits and torque specifications.

PDF Search, Bookmarks, and Page Breakdown

Text search and diagram detail: The PDF is partly searchable, with OCR errors and some technical pages without searchable text. Embedded bookmarks cover the main sections, subsections, and index. Small labels in the wiring diagrams require zooming.

Supplied as one printable 435-page PDF in English: 421 pages of manual content and front matter, two cover pages, and 12 blank pages, including pages bearing only headers and footers. All are included in the total.