The model was introduced in October 1961 and was the flagship of the Implematic range.

The 990 was powered by a four-cylinder diesel engine that produced 52.5hp. This was mated to a high/low gearbox that provided six forward and two reverse speeds. ‘Livedrive’ and a two-speed pto were fitted as standard, and the tractor had a stronger back-end and a larger clutch than the David Brown 950.

Like the other models in the range, the 990 Implematic was an attractively styled machine with a currant red and primrose yellow livery. The tractor came with a full lighting kit and 16” front and 32” rear wheels.

The Implematic hydraulic system fitted to the 990 incorporated a depth control mechanism, thereby allowing the tractor to cater for implements with and without a depth wheel.

The David Brown 990 Implematic was modified in August 1963. Later models can be identified by the position of their 12-volt battery behind the tractor’s front grille — earlier examples had two six-volt batteries located either side of the driver’s seat. As a result, later models have a slightly longer bonnet than their predecessors — something to be mindful of if sourcing a replacement bonnet for restoration.

Some 40,600 David Brown 990 Implematic tractors rolled off the production line before the orchid white and chocolate brown 990 Selectamatic was unveiled in October 1965. The new model had a red exhaust and red/gold front grilles; otherwise, it was very similar to its predecessor in design.

The main feature of the tractor was, of course, its Selectamatic hydraulic system which incorporated depth, height and traction control, initially operated by three taps but later controlled using a switch with a plate displaying the function selected. A single control lever, also located on the operator’s right-hand side, provided the adjustment required.

The 990 Selectamatic had a power-output of 55hp, and a new gearbox providing 12 forward and four reverse speeds was available.

A synchromesh transmission was introduced with the launch of the new David Brown line-up in 1971.

The new 990 could easily be distinguished from its predecessor by the location of the tractor’s headlights inside the front grille as opposed to being mounted either side of the nosecone. A new David Brown emblem was also introduced with the ‘D’ resembling the Greek letter Delta.

The 990 was now fitted with a ‘weather cab’ as standard. This consisted of a basic safety frame and roof — flexible or rigid doors and panels could be specified as optional extras.

The 990 model designation disappeared when the David Brown ‘90 Series’ models were launched in 1979. The 990’s earliest incarnation in Implematic form was a particular favourite among the farming community, earning a reputation both for reliability and versatility.

The flagship model of any tractor range is usually the most sought after for restoration today, and the 990 is certainly no exception. David Brown Implematic tractors are becoming scarce, so now is the time to find an example suitable for refurbishment!

*robertkierans@hotmail.com