David Brown 990, 995 & 996

The David Brown 990, 995 and 996 are among the best-known tractors from the Meltham-built David Brown range. Strong four-cylinder diesels, compact dimensions and the distinctive Selectamatic hydraulic system made them popular working tractors, and many remain in use or restoration today.

Machine of the Month

This guide covers the 990, 995 and 996 family in general. Engines, transmissions, PTO arrangements, hydraulics, brakes, steering and electrical equipment vary with production period and specification. Use the correct model and serial-range workshop manual for exact settings.

1. The David Brown 990 Family

The 990 became one of David Brown’s most successful medium-sized tractors.

Later 995 and 996 models developed the same general design philosophy with changes to:

  • Engine specification
  • Transmission options
  • Hydraulic controls
  • Operator equipment
  • Electrical and cab equipment

2. David Brown 990

The 990 is commonly encountered as a four-cylinder diesel tractor with David Brown’s own transmission and hydraulic system.

It became particularly popular for:

  • General farm work
  • Hay and PTO work
  • Cultivation
  • Transport
  • Loader duties

3. David Brown 995

The 995 continued the medium-horsepower David Brown line with updated styling and detail changes.

Many parts look similar to the 990, but exact interchangeability should never be assumed without checking part numbers or the correct parts catalogue.

4. David Brown 996

The 996 is closely related to the 995 but was produced with specification differences that can affect:

  • Transmission
  • PTO
  • Hydraulics
  • Brakes
  • Operator controls

5. Identification Matters

Before ordering parts, record:

  • Tractor serial number
  • Engine number
  • Transmission type
  • Hydraulic-control layout
  • PTO arrangement
  • Cab or platform type
Do not rely on decals alone

David Brown tractors were often repaired with second-hand components. Bonnets, rear ends, engines and hydraulic parts may have been changed during decades of use.

6. Four-Cylinder Diesel Engine

The David Brown four-cylinder diesel is generally durable when properly maintained.

When assessing an engine, check:

  • Cold starting
  • Oil pressure
  • Blow-by
  • Exhaust smoke
  • Coolant condition
  • Oil and coolant leaks

7. Hard Starting

Before blaming the injection pump, check:

  • Battery condition
  • Starter speed
  • Compression
  • Fuel supply
  • Filters
  • Air in the fuel system
  • Cold-start equipment
  • Injection timing

8. Fuel Injection System

Mechanical injection systems depend heavily on clean fuel and correct timing.

Common age-related problems include:

  • Air leaks on suction side
  • Blocked filters
  • Injector wear
  • Leaking return pipes
  • Pump seals leaking

9. White Smoke During Starting

Possible causes include:

  • Low compression
  • Slow cranking
  • Incorrect injection timing
  • Poor injector spray
  • Cold engine

10. Black Smoke Under Load

Check:

  • Air cleaner restriction
  • Fuel setting
  • Injector condition
  • Engine load
  • Exhaust restriction

11. Engine Oil Pressure

Low pressure when hot can point to:

  • Bearing wear
  • Oil-pump wear
  • Incorrect oil
  • Relief-valve leakage

Confirm true pressure with the correct gauge and specification.

12. Cooling System

Check:

  • Radiator cleanliness
  • Water pump
  • Fan belt
  • Thermostat
  • Hoses
  • Coolant concentration

Internal scale and external chaff/dust blockage are both common on older tractors.

13. Transmission

David Brown gearboxes are generally strong but can suffer from age and contaminated oil.

Check for:

  • Gear noise
  • Bearing rumble
  • Jumping out of gear
  • Difficult selection
  • Water in oil

14. Clutch

Common clutch complaints include:

  • Slipping
  • Dragging
  • Release-bearing noise
  • Clutch stuck after storage

15. Dual or Multi-Stage Clutch Arrangements

Depending on specification, clutch and PTO arrangements can differ.

Before adjustment, identify the exact clutch system and use the correct pedal/free-play and internal setting procedure.

16. PTO System

The PTO may use different drive arrangements depending on model and specification.

Check:

  • Engagement lever
  • Clutch relationship
  • Shaft condition
  • Oil leaks
  • PTO brake or stop behaviour where fitted

17. PTO Will Not Engage

Possible causes include:

  • Clutch adjustment
  • Linkage fault
  • Internal selector wear
  • Damaged PTO clutch components

18. Selectamatic Hydraulics

The Selectamatic hydraulic system is one of the defining features of these tractors.

It allows the operator to select different control modes for:

  • Position control
  • Draft control
  • External hydraulic services

19. Selectamatic Control Selector

The selector system must be in the correct position for the intended function.

Incorrect lever or selector position can create symptoms that look like a hydraulic fault.

Learn the Selectamatic controls before dismantling

A surprising number of apparent faults are caused by control position, adjustment or contamination rather than a failed hydraulic pump.

20. Hydraulic Lift Will Not Raise

Check:

  • Oil level
  • Correct control position
  • Filter condition
  • Pump supply
  • Control valve
  • Internal leakage

21. Lift Works Cold but Weakens Hot

Possible causes include:

  • Pump wear
  • Internal valve leakage
  • Lift-cylinder leakage
  • Oil too thin or incorrect

22. Linkage Will Not Lower

Possible causes include:

  • Control valve sticking
  • Incorrect selector position
  • Mechanical linkage fault
  • Internal adjustment problem

23. Linkage Hunts Up and Down

Possible causes include:

  • Internal leakage
  • Incorrect adjustment
  • Control-valve problem
  • Draft-sensing linkage wear

24. Hydraulic Filters and Cleanliness

The Selectamatic system is sensitive to contamination.

Dirty oil can affect:

  • Small valves
  • Control passages
  • Pump performance
  • Lift response

25. Remote Hydraulics

External hydraulic services may be used for:

  • Trailer tipping
  • Loader valves
  • Remote cylinders

Many tractors have been modified, so trace the actual pipework rather than assuming it remains factory standard.

26. Steering

Depending on model and specification, tractors may use:

  • Manual steering
  • Power-assisted steering
  • Hydrostatic-type arrangements on later versions

Check the actual system fitted.

27. Common Steering Wear

  • Track-rod ends
  • Drag links
  • Kingpins
  • Front axle pivot
  • Steering box or valve wear

28. Front Axle and Loader Use

Loader tractors often show wear at:

  • Centre pivot
  • Kingpins
  • Wheel bearings
  • Steering joints

Greasing is essential.

29. Brakes

Brake arrangement varies by model and year.

Check:

  • Both sides balanced
  • Pedal travel
  • Linkage freedom
  • Oil contamination
  • Internal wear

30. Rear Axle and Final Drives

Listen for:

  • Bearing rumble
  • Gear whine
  • Knocking under load

Inspect for oil leaks around:

  • Half shafts
  • Final drives
  • Brake housings

31. Electrical System

Older tractors may have been altered with:

  • Alternator conversions
  • Replacement starter switches
  • Additional lighting
  • Non-original instrument wiring

Identify what is actually fitted before troubleshooting.

32. Long-Storage Problems

Common issues include:

  • Stuck clutch
  • Water in transmission/hydraulic oil
  • Seized brakes
  • Blocked fuel filters
  • Corroded electrical connections
  • Perished hoses and tyres

33. Water in Transmission/Hydraulic Oil

Milky oil can enter through:

  • Damaged gear-lever boots
  • Breathers
  • Condensation
  • Outdoor storage

Contamination can badly affect the Selectamatic system.

34. Before First Start After Storage

  1. Confirm engine turns freely.
  2. Check oil and coolant.
  3. Clean fuel supply.
  4. Inspect air intake.
  5. Check transmission/hydraulic oil.
  6. Check clutch and brakes.
  7. Inspect wiring and battery cables.
  8. Confirm throttle and stop controls operate.

35. Buying a David Brown 990 / 995 / 996

Check:

  • Serial/model identity
  • Cold starting
  • Oil pressure
  • Blow-by
  • Gearbox noise
  • Clutch operation
  • PTO operation
  • Selectamatic hydraulic performance
  • Steering play
  • Brake performance

36. Restoration Priorities

  1. Identify the exact model and major components.
  2. Make engine and cooling system reliable.
  3. Repair brakes and steering.
  4. Repair clutch, transmission and PTO.
  5. Clean and repair Selectamatic hydraulics.
  6. Tidy electrics.
  7. Finish with paint and cosmetics.

37. Workshop Checklist

System Check
Identification 990, 995 or 996 and serial range confirmed.
Engine Cold start, smoke, oil pressure and blow-by.
Transmission All gears select; no serious noise.
Clutch/PTO No slip/drag; PTO operates correctly.
Selectamatic hydraulics Correct control selection, lift and hold.
Oil/filter Clean, correct and water-free.
Steering No unsafe play.
Brakes Balanced and effective.
Electrics Charging/start circuits sound.

Related Agrimanual Manuals

Frequently Asked Questions

Are the 990, 995 and 996 basically the same tractor?

They belong to the same broad David Brown family, but engines, transmissions, hydraulics, brakes and equipment can differ. Use the correct manual for the exact model and serial range.

Why does the Selectamatic linkage not lift?

Check oil level, control positions, filter condition, pump supply, internal leakage and control-valve operation before dismantling major components.

Why does the linkage work when cold but fail when hot?

Oil thinning can expose pump wear or internal hydraulic leakage.

Can dirty oil cause Selectamatic problems?

Yes. Small hydraulic passages and valves can become contaminated, making cleanliness especially important.

Why is my David Brown hard to identify?

Many tractors have had engines, bonnets, rear ends or other components replaced. Use serial numbers and actual component details rather than decals alone.

Machine of the Month conclusion

The David Brown 990, 995 and 996 remain excellent working classics. Their engines and transmissions are straightforward, while the Selectamatic hydraulics reward careful diagnosis and clean, correctly specified oil.