| Manufacturer |
David Brown |
| Price |
- |
| Model |
990 |
| Equipment Type |
Utility Tractors |
| Factory |
Meltham Mills, Huddersfield, England |
NEBRASKA TRACTOR TEST 903 2
| Description |
3L diesel 6-speed 2WD June 11 - 19, 1965 Link: Nebraska Tractor Test 903 file PTO performance Drawbar performance Gear 3 used for power test Gear 1 used for pull test |
| Power at rated engine speed |
51.60hp / 38.5kW |
| Fuel use |
3.4gal/hour / 12.9l/hour |
| Power at rated PTO speed |
48.49hp / 36.2kW |
| Max power |
43.47hp / 32.4kW |
| Max pull |
6,039lbs / 2739kg |
DAVID BROWN 990 POWER
| Engine |
52hp / 38.8kW |
| Drawbar (claimed) |
43hp / 32.1kW |
| PTO (claimed) |
48hp / 35.8kW |
| Drawbar (tested) |
43.47hp / 32.4kW |
| PTO (tested) |
51.60hp / 38.5kW |
ENGINE DETAIL
The David Brown 990 tractor features a 4-cylinder liquid-cooled diesel engine with a displacement of 3.0L, offering 52hp at a rated RPM of 2200. Its oil bath air cleaner supports optimal filtration, while the 17:1 compression ratio ensures efficient combustion for better torque and power delivery through the operating RPM range of 700-2200. Key considerations include its relatively compact oil and coolant capacities, which could necessitate more frequent maintenance checks to avoid overheating and ensure proper lubrication during heavy-duty tasks.
| Description |
David Brown diesel 4-cylinder liquid-cooled |
| Displacement |
185.8ci / 3.0L |
| Bore/Stroke |
3.625x4.50inches / 92x 114mm |
| Power |
52hp / 38.8kW |
| Air cleaner |
oil bath |
| Compression |
17:1 |
| Rated RPM |
2200 |
| Operating RPM |
700-2200 |
| Starter volts |
12 |
| Oil capacity |
7.8qts / 7.4L |
| Coolant capacity |
14.4qts / 13.6L |
DAVID BROWN 990 ENGINE
The David Brown 990 features a 3.0L 4-cylinder diesel engine, providing a robust power output suitable for medium-duty agricultural tasks. Its 13.74-gallon (52.0L) fuel tank offers a decent operating range, which can enhance productivity during extended work sessions but may require frequent refueling for larger-scale operations. Consider the tractor's weight and torque characteristics when coupling with implements to ensure optimal performance without compromising traction or power delivery.
| Description |
David Brown 3.0L 4-cyl diesel |
| Fuel tank |
13.74gal / 52.0L |
TRANSMISSIONS OVERVIEW
The David Brown 990 tractor features a 6-speed gear system with a 12-speed partially synchronized transmission, allowing for improved gear selection and smoother operation under varying loads. Advantages include enhanced efficiency during field work and versatility for different terrain conditions; however, the complexity of the partially synchronized system may pose maintenance challenges for operators unfamiliar with advanced transmission systems. In scenarios where quick speed adjustments are necessary, such as in hilly terrains or diverse crop applications, the 990's transmission setup can significantly improve productivity.
| Description |
6-speed gear 12-speed partially synchronized |
TRANSMISSION 1
The David Brown 990 tractor features a 6 forward and 2 reverse gear system with a dry disc clutch measuring 279mm, facilitating effective torque transfer. This configuration offers enhanced versatility in both low and high ranges, making it suitable for various agricultural tasks. However, operators may need to adjust to the gear shifting patterns for optimal performance in different scenarios.
| Type |
gear |
| Gears |
6 forward and 2 reverse |
| Clutch |
279mm dry disc |
| Description |
Three gears (1-3) plus reverse (R) in low and high ranges. |
TRANSMISSION 2
The David Brown 990 features a partially synchronized 12-speed transmission, offering enhanced adaptability for varying conditions since its introduction in 1963. The transmission allows for efficient power management with a range of 12 forward and 4 reverse gears, facilitating better performance in diverse agricultural tasks. However, the partially synchronized design may pose a challenge during gear shifts, especially under load, requiring skilled operation to prevent wear.
| Type |
partially synchronized |
| Gears |
12 forward and 4 reverse |
| Description |
Twelve-speed transmission introduced in 1963 |
MECHANICAL
The David Brown 990 tractor features a 4x2 2WD chassis, offering good traction for general utility tasks but limited off-road capability. The mechanical rear differential lock enhances traction in slippery conditions, while the optional manual hydrostatic steering adds maneuverability, albeit with potential fatigue for extended use. With a 6-speed gear or optional 12-speed partially synchronized transmission, operators can optimize engine power and speed for various tasks, though manual gear shifting may require skill and experience.
| Chassis |
4x2 2WD |
| Differential lock |
mechanical rear |
| Steering |
manual hydrostatic power (optional) |
| Brakes |
differential mechanical expanding shoe |
| Cab |
Open operator station |
| Transmissions |
6-speed gear 12-speed partially synchronized |
HYDRAULICS
| Type |
open center |
| Pressure |
2000psi / 137.9bar |
| Total flow |
7.4gpm / 28.0lpm |
TRACTOR HITCH
POWER TAKE-OFF (PTO)
| Rear PTO |
transmission/live (optional) |
| Clutch |
dry disc |
| Rear RPM |
540/1000 (1.375) |
| Engine RPM |
540@1800 (Low) / 540@1100 (High) / 1000@2000 |
DAVID BROWN 990 TIRES
The David Brown 990 tractor, equipped with standard agricultural tires (6.00-16 front and 11-32 rear), offers a balanced tire setup for enhanced stability and traction in fieldwork scenarios. The larger rear tires provide improved ground engagement and flotation, which is beneficial for plowing and tilling in various soil conditions. However, the front tire size may limit maneuverability in tight spaces, posing a challenge in certain farming applications where agility is required.
| Standard tires (ag) |
Front: 6.00-16. Rear: 11-32 |
DIMENSIONS
| Wheelbase |
76.75inches / 194cm |
| Length |
118inches / 299cm |
| Width |
67inches / 170cm |
| Height (hood) |
56inches / 142cm |
| Clearance (front axle) |
20inches / 50cm |
| Front tread |
52/56/60/64/68/72/76inches / 132/142/152/162/172/182/193cm |
| Rear tread |
52/56/60/64/68/72/76inches / 132/142/152/162/172/182/193cm |
DAVID BROWN 990 WEIGHT
| Operating |
4272lbs / 1937kg 4312lbs / 1955kg (live PTO) |
| Ballasted |
5880lbs / 2667kg |
DIMENSIONS & TIRES
The David Brown 990 tractor, with a wheelbase of 76.75 inches and a weight ranging from 4272 to 4312 pounds, offers a stable platform ideal for medium-duty agricultural tasks. The specified front tire size (6.00-16) provides good maneuverability, while the rear tires (11-32) deliver traction for heavier loads, making it suitable for implements like plows or cultivators. However, the relatively compact wheelbase may limit stability in steep terrain, presenting a challenge during operations on uneven ground.
| Wheelbase |
76.75inches / 194cm |
| Weight |
4272 to 4312 pounds |
| Front tire |
6.00-16 |
| Rear tire |
11-32 |
990 SERIAL NUMBERS
| Location |
Frame, right side |
| 1961 |
440001 |
| 1962 |
441323 |
| 1963 |
450376 |
| 1964 |
460376 |
| 1965 |
472273 |
| 1966 |
483768 |
| 1967 |
496283 |
| 1968 |
504690 |
| 1969 |
808150 |
| 1970 |
818301 |
| 1971 |
826009 |
| 1972 |
850600 |
| 1973 |
854403 |
| 1974 |
859367 |
| 1975 |
863900 |
| 1976 |
11070001 |
| 1977 |
11080236 |
| 1978 |
11089141 |
| 1979 |
11096828 |
| 1980 |
11104577 |
ELECTRICAL
| Charging system |
generator |
| Batteries |
2 |
| Battery volts |
6 |
