900 Series (1955-1957)

Sadly, this model has often been quoted as David Brown’s worst tractor, and it is true that it did earn itself quite a reputation. Yet, from the outset, it had been intended that the 900 should only be a stop-gap measure, an interim tractor, before the firm began producing a tractor which would be suited to fast-advancing mechanisation in the agricultural world. Simultaneous with the introduction of the David Brown 900, came the time when the company began a new way in designating its various models.

David Brown 900

As we mentioned earlier, the DB25 & DB30 delivered that level of horsepower, and a bit more, but some manufacturers were not as scrupulous and their model numbers were marginally higher than the actual horse-power which the tractors delivered. David Browns were not prepared to indulge in this practice, even though it obviously influenced customers to buy certain types of tractor. The outcry which came about when tractors failed to deliver the purported horse-power, subsequently led to the establishment of National Tractor Testing. The Marketing Department at Meltham Mills came up with the idea that they should use a designation which in no way could be construed as horse-power, and because of this they devised the 900 numbering series.

In 1954 David Browns began experimenting with a new prototype, in which it intended to embody all the features needed to up-date the Cropmaster and its stripped down 25 and 30 successors. This was to be a completely new tractor, and it was known as the VAD5. Herbert Ashfield drew once more on his recollections when I asked him how this came about; ‘From around 1954-5, there was pressure for an entirely new design of tractor as the Cropmaster was supposed to be a bit dated. It must have been when it was a bit flat at the works, as I was commissioned to design a basically new tractor.

DB 900

One of the things we had trouble with was the cast iron frame, which was originally cast in just one piece; and, as there were only two foundries in the country that could cast it, we had real trouble in getting supplies at times. I talked this problem through with our Chief Designer, and we decided that the frame could be chopped in half and made in two pieces, which would (in turn) make it easier for small foundries to cast it. But this was only a temporary measure, and the idea which someone put forward was to copy the Fordson Major and have a steel sub-frame on which we could easily mount the engine and gain more flexibility in manufacture. However, as things turned out, it never worked out that way, but we did make various prototypes to test the idea. Another thing we wanted to do was get rid of the type of steering rod which we had used since the early days, so we made up a model with the steering over the top. It looked very American when it was finished, and it too never went into production.

However, a lot of the ideas behind the VAD5 were ultimately incorporated in production of the 900. For example, we found that we could get the same features as we had in the existing line, by using the same castings and engine mounts etc. When we came to the actual prototype of the 900, we also had a large number of new features which we wanted to incorporate, including: An adjustable heavy duty front axle which would give better steering geometry on the wider track widths; Live power take off shaft and power lift pump able to keep running when the tractor was stopped; Weight transfer from implement to tractor rear wheels. namely traction control, which would prevent wheel spin under heavy loads; Differential lock; Hydraulic depth control for use with mounted implements lacking depth wheels; Comfort seat (instead of the pan seat fitted to 25 and 30 series); Revised styling and a dual colour scheme; Batteries positioned each side of the seat or in front of radiator; A repositioned air cleaner in front of radiator (inside the bonnet) instead of allowing it to hang externally on the side of the engine; and last, but by no means least, a distributor injection pump on diesel engines which was intended to be cheaper, smaller and give smoother running. Not all these features were incorporated in the 900, and due to its short life, some of the improvements were actually carried over into the 950 or 990.’

1954 David Brown 900

During its launch at the Smithfield Show Mr. David Brown junior, said ‘Our policy must always be to give value for money that is something about which we, as Yorkshiremen, are very particular and we are convinced that the 900 tractor upholds that tradition. With its twin range gear box giving 6 forward and 2 reverse gears, a 2-Speed PTO and pulley, improved one-piece bonnet styling, overload release, independent foot brakes and Traction Control Unit it seemed to give really good value for money. This was particularly pleasing when it was revealed that its ex-works price was just £593 10s (£593.50p), a snip at £42 10s (£42.50p) less than the 30D. Providing extra output with greater economy, it should have been the tractor for the mid-50s, but it was sadly not to be.

Unfortunately, the 40hp 900 got off to a very bad start due to its new distributor injection pump, made by CAV, that was fitted to all diesel models. Although prototypes had been thoroughly tested, production pumps were prone to seizure. This was ultimately found to be due to the use of a different (probably cheaper) steel for the pump plungers and body. Tom Lazenby recalls how the matter gave his sales department a major headache until it was finally resolved. ‘The fuel pump on the 900 frightened us to death because of all the troubles it gave but we couldn’t revert back to the in-line pump, because this couldn’t work on the 900 and although we still had the 25s and 30s in production, all we were building at the time were 900s.

1957 David Brown 900 & Ransome Planter

Things very nearly came to a full stop. The way things were going it could have ended in a spectacular law suit with CAV, and probably would have done if it hadn’t been for an incident which transpired on Huddersfield station. Obviously we were trying hard to find what was wrong and so were CAV. Pumps were going up and down between Meltham and the CAV factory, going by rail, by wagon, by everything just as they were coming back to us from overseas by air and by sea for re-servicing. We just couldn’t get the things to work, so we sent them back to the makers to see if they could. Oddly enough, CAV could get them to work again, but don’t ask me how: yet when they came back to us then they began to fail again. As the situation worsened, the Service Department were under so much pressure to get tractors moving right across Europe that they had to rob those coming in for the assembly line.

In fact, after a while they had got so many pumps out of the line. that there weren’t enough engines going through to keep production going. By this time the night shift was lucky if it ‘had half the pumps it needed to get it through to the morning. Well you can’t go on making engines without pumps because you can’t leave them to be fitted afterwards as the complete engine assemblies had to be tried on the test-bed. The strange thing was, the pumps that were being fitted would work on the engine test-bed, and they didn‘t fail when the finished tractor was tested up and down the Knowle, it was afterwards when they failed usually when they began their working lives. We couldn’t understand this, nor could CAV. Then, one night, we had an incident at Huddersfield station and it all became clear.

David Brown 900 & Disc Harrow

Because of the acute shortage of pumps, CAV were managing to make sufficient one day to meet our production needs the next, but because they were so urgently needed they had to send these up by passenger train. We used to send a van down to meet these trains coming in from the Birmingham area that were carrying a box full of pumps; almost invariably the train would have a box full of pumps on, sometimes two boxes of pumps or even more. I don’t know how big these boxes were, but one night, either the man in the train threw them out or they were dropped on the station platform with a quite a bang! Our driver suddenly guessed that this could be what was causing the problem, so he brought them directly round to the Engine Test Department, and we put them straight on to test.

None of them worked at all! So what was happening to make the pumps fail if they were dropped or banged? Well our engineers began to take a closer look at these pumps, and what they found was this. When they built the units CAV had used a component inside the pump and somehow, during the machining of it, it had built up stress. However, when you dropped them or put the pumps into regular service, it relieved the stress, the component jammed and the pump failed. Within days of making this revelation, we were out of trouble with that, but our reputation had taken an awful battering.’

Herbert Ashfield continues the story, ‘David Brown’s were relatively lucky, because on our engines the pump coupling key sheared and we only needed a new pump; on some other makes of engine, the timing gears stripped and the valves went through the piston crowns necessitating a new engine. CAV did a campaign change on all their pumps but this did nothing to increase the 900’s popularity.’

David Brown 900 Tractor

Another problem noted in the 900 was found with the steering, especially after the safety authorities introduced a limit on the amount of play at the steering wheel rim and applied it enthusiastically to tractors. Herbert Ashfield once again picks up the account: ‘The limit was about 2” I believe, but the 900 seemed to develop 2 1/2 and stay there, so several new steering relay lever bearings had to be fitted to maintain compliance with this requirement. The plan to install a comfort seat was dropped around this time and, while this no doubt kept the price down, it was not a feature that could be used by the salesman as a talking point.

Then, in late 1957 a live power take off and power lift pump were introduced and this kept sales going aided by the superior performance of the machine over the old “Cropmaster” range.’ In 1958 Brown’s decided to not make any further improvements to the 900, and instead they designed the other outstanding features into the new model it was proposing, thereby making a clean break with the past. Thus, while the 25s and 30s were still being produced, the 900 went out of production prematurely in the summer of 1958 and it was superseded by the 950 which was free of teething troubles and enjoyed a good reputation from the word go. With the Livedrive versions which became an option during production run, a total of 13,770 of the 900s were produced, including a small batch of tractors designated as 903 (a row-crop version for the Californian market) but still bearing a 900 badge. However, when the last of the blue-wheeled tractors was taken on a test run down Meltham Mills Road for the final time, there were more than a few people who were relieved to see the back of them.













VAD6 50D


900 Series


VAD12 2D


950 Series


850 Series


880 Series


990 Series