Target Audience:
Owners, mechanics, and technicians responsible for the maintenance and repair of David Brown 950, 990, 995, and 996 tractors.
Industry Context:
David Brown tractors were known for their robust build and reliability, competing with brands like Massey Ferguson, Fordson, and International Harvester in the agricultural sector.
Manual Value Proposition:
Provides essential, factory-authorized procedures to maintain and repair these classic tractors, extending their operational life and ensuring correct functionality.
Historical Significance:
Covers tractors that were instrumental in agricultural modernization during their production era.
Primary Coverage:
Comprehensive service, repair, and maintenance procedures for David Brown 950, 990, 995, and 996 agricultural tractors.
Secondary Coverage:
Troubleshooting, diagnostics, electrical systems, hydraulic systems, engine overhaul, transmission repair, and component rebuilding.
Estimated Pages:
Highly variable depending on specific edition, but typically 300-600+ pages for a complete factory service manual.
Type:
Factory Service Repair Manual
Engine:
Detailed breakdown of the AD/DA series diesel engines (e.g., AD4.248, AD6.354) including cylinder head, block, crankshaft, pistons, rings, lubrication, cooling, and fuel systems.
Transmission:
Coverage of the David Brown constant mesh, sliding mesh, and synchromesh transmissions, including gearbox overhaul, clutch assembly, PTO (Power Take-Off) operation, and final drives.
Hydraulics:
In-depth coverage of the David Brown 'Vari-Drive' or 'Haldex' hydraulic system, including hydraulic pump, lift cover, draft control, position control, hydraulic fluid specifications, and troubleshooting.
Electrical:
Wiring diagrams, component testing (alternator, starter motor, battery, lights), ignition system (if applicable to specific models/engine variations), and dashboard instrumentation.
Front Axle Steering:
Service and repair procedures for the front axle, steering knuckles, tie rods, and steering box, including lubrication and alignment.
Braking System:
Details on the drum brake system, brake pedal linkage, brake fluid, and adjustments.
Bodywork Chassis:
Information on chassis components, fenders, seat assembly, drawbar, and minor body panel repairs.
Engine Overhaul:
Complete engine rebuilding procedures, including piston and ring replacement, bearing replacement, valve servicing, and cylinder head gasket replacement.
Transmission Rebuild:
Step-by-step instructions for disassembling, inspecting, and reassembling the gearbox and associated components.
Hydraulic System Repair:
Troubleshooting and repair of hydraulic pump failures, cylinder leaks, and control valve issues.
Tune Up Maintenance:
Scheduled maintenance tasks, including oil changes, filter replacements, valve adjustments, and fuel system bleeding.
Troubleshooting Diagnostics:
Diagnostic charts and procedures for identifying and rectifying common problems across all major systems.
Electrical Diagnostics:
Troubleshooting electrical faults using wiring diagrams and component testing methods.
Depth Of Coverage:
Comprehensive, covering everything from basic operator maintenance to full mechanical overhauls and component rebuilding.
Diagnostic Capabilities:
Includes detailed diagnostic procedures, specifications, and tolerances for accurate fault finding.
Rebuild Instructions:
Provides detailed instructions for rebuilding major assemblies like engines, transmissions, and hydraulic pumps.
File Type:
PDF (Portable Document Format)
Searchable Text:
Likely yes, depending on the quality of the OCR during digitization, allowing for keyword searches.
Digital Rendering:
Dependent on the original source material and digitization quality. Typically clear text and legible diagrams.
Original Binding:
Not applicable for PDF format, but original manuals were typically bound with staples, perfect binding, or ring binders.
Original Paper Quality:
Typically printed on durable, uncoated paper suitable for workshop environments.
Engine Family:
David Brown AD/DA Series Diesel Engines
Common Engine Variants:
AD4.248 (4-cylinder), AD6.354 (6-cylinder)
Bore Stroke Ad4 248:
3.625" x 5.00" (92.1 mm x 127.0 mm)
Displacement Ad4 248:
248 cubic inches (4.07 Liters)
Bore Stroke Ad6 354:
3.875" x 5.00" (98.4 mm x 127.0 mm)
Displacement Ad6 354:
354 cubic inches (5.80 Liters)
Horsepower 950 Implements:
Approximately 50-60 PTO HP (Varies by model and engine)
Horsepower 990 Implements:
Approximately 60-70 PTO HP (Varies by model and engine)
Torque Specifications:
Specific torque figures for critical engine components (e.g., head bolts, main bearings) will be detailed within the manual.
Injection Type:
Direct Injection
Injection Pump Manufacturer:
Likely Simms, CAV, or Lucas (specifics in manual)
Gearbox Type 950:
8-Speed Constant Mesh (4 forward, 2 reverse, plus high/low range)
Gearbox Type 990 995 996:
8-Speed Constant Mesh (4 forward, 4 reverse) or 12-speed with Multi-Power option
Multi Power Transmission:
Available on some models (e.g., 990), offering a powershift capability for on-the-go gear changes in selected ranges.
Pto Options:
Standard 540 RPM PTO, some models may have optional 1000 RPM PTO.
Clutch Type:
Dual-stage clutch (for transmission and PTO operation).
Wheelbase Typical:
Approx. 75-80 inches (190-203 cm) - Varies by model and configuration.
Overall Length Typical:
Approx. 120-130 inches (305-330 cm) - Without implements.
Overall Width Typical:
Approx. 65-75 inches (165-190 cm) - At rear wheels, without extensions.
Operating Weight Typical:
Approx. 4,000 - 5,500 lbs (1,814 - 2,495 kg) - Varies significantly by model and ballast.
Drawbar Hitch Type:
Category 2, 3-point linkage, heavy-duty drawbar.
Historical Safety Standards:
Tractors from this era predated stringent modern safety regulations. Features like ROPS (Roll-Over Protective Structure) and seatbelts were often optional or not standard.
Braking System Performance:
Drum brakes providing adequate stopping power for agricultural use when properly maintained. Manual will detail adjustment procedures.
Operator Station:
Basic operator platform with fenders. Manual will cover seat adjustments and pedal placement for safe operation.
Engine Oil Change:
Typically every 100-150 operating hours or annually. Manual will specify exact interval and oil type.
Hydraulic Fluid Change:
Recommended every 500-1000 operating hours or annually. Manual will detail filter replacement and fluid checks.
Transmission Oil Change:
Typically every 800-1200 operating hours. Manual will provide capacity and grade.
Air Filter Service:
Frequent checking and cleaning, especially in dusty conditions. Replacement intervals will be specified.
Fuel Filter Replacement:
Recommended at regular intervals, often with oil changes or as per manual guidance.
Engine Oil Grade:
Typically SAE 30 or 15W-40 Heavy Duty Diesel Engine Oil. Manual will provide exact API service classification (e.g., CD, CE).
Hydraulic Fluid Type:
David Brown Hy-Trans or equivalent high-quality tractor hydraulic fluid (UTTO - Universal Tractor Transmission Oil). Manual will list specifications and alternatives.
Transmission Oil Grade:
Often the same as hydraulic fluid (Hy-Trans) or a specified gear oil. Capacity and grade detailed in manual.
Coolant Type:
Ethylene glycol-based antifreeze mixture. Manual will specify ratio and type.
Common Wear Points:
Hydraulic lift issues (pump wear, cylinder leaks), clutch wear, PTO engagement problems, and gearbox synchromesh wear.
Engine Considerations:
Potential for oil consumption with high hours, injection pump timing, and glow plug issues in colder climates.
Electrical Aging:
Aging wiring harnesses, corrosion on electrical connections, and starter/alternator wear are common in older vehicles.
David Brown Legacy:
David Brown Tractors Ltd. was a British manufacturer known for producing reliable and durable tractors from the post-war era until its acquisition by Tenneco (owner of J.I. Case) in 1971. The brand continued under the J.I. Case/CASE IH umbrella.
Series Development:
The 950, 990, 995, and 996 represent a progression of David Brown's popular medium-horsepower tractors, evolving from earlier models like the 25, 30, 50, 700, and 850 series. They were known for their versatile hydraulic systems and sturdy transmissions.
Manufacturing Locations:
Primarily Meltham, Yorkshire, England.
Production Period:
The 950/990 series began production in the early 1960s, with the 995/996 models introduced later in the decade and into the early 1970s.
