Braking New Ground
In addition to the pacey performance of its 360hp engine on our Scottish test route, DAF’s CF75 was also equipped with a powerful extra deceleration system. John Henderson, a man who’s rarely stopped in his tracks, reports on a retardation revolution. THESE DAYS there’s no such thing as a truck with mediocre brakes and most commercial vehicle models produced now have an additional complementary system such as an exhaust or engine brake. Last October I tested DAF’s CF75.360 tipper on our Scottish test route, which was equipped with the latest version of ZF’s hydrodynamic intarder. In my four years as tester for Transport News, I’ve never driven anything like this 6x4 rigid. It is literally a truck which stops equally as well as it goes! Naturally I’ll cover the polished forward moving performance of the CF75 in the following paragraphs, but this time around it’s a truck’s stopping power that makes the headlines. The latest version of ZF’s intarder generates 25% more braking efficiency, weighs less and operates quieter than its predecessor model. Coupled to the rear section of the gearbox and taking up little extra in overall dimensions, the new intarder can be connected to manual as well as automatic transmission systems in a much easier way and is optimally integrated into the vehicle’s brake management system and cruise control function. Operated by a three position stalk located on the right of the CF’s steering column, the ZF intarder capably handled around 90% plus of my braking requirements through the entire day’s trial. This left the main service units cool and ready for action at all times and for the last 20 miles or so I was forced to give them some use just to report back on their performance! Having formed such a trusted partnership with the intarder throughout the day, I wondered about the result of my continual usage on gearbox oil temperatures and mechanical friction levels. Thankfully the answer was ‘absolutely no effect at all’, as the ZF unit is in charge of both transmission cooling and heating functions and the hydrodynamics ensure wear free operation. Despite costing £4,400 as an optional extra, the ZF intarder is well worth the expense, as what price do you put on safety? Further savings are delivered with this kit, as brake applications are reduced by up to 90%, thereby increasing the life span of the attendant discs or drum between two to five times, depending of course on a particular motor’s application. The gearbox and its internal parts should also last longer, as even when not in use the intarder reduces the average oil temperature slightly, which prolongs associated component life. I used the intarder on virtually every approach to junctions or hazards and also on the three biggest downhill sections of the route. Two of these descents run into busy roundabouts, whilst the other is a curved motorway junction over bridge and for the first time ever on a test, I safely traversed this tricky trio without touching the service brake pedal. Our yellow steed for testing was fitted with the top option power output of 360hp/265kw and operators who require slightly less grunt will appreciate the other 250hp/183kw choice. Paccar’s PR 9.2 litre engine is a six in-line unit with after treatment courtesy of selective catalytic reduction (SCR). Maximum power on the 360 is at 2,200rpm and 1,450nm of torque is delivered between 1,200 to 1,700rpm. Running fully loaded at 26 tonnes with a full load of aggregate, the engine felt lively and responsive, as if it was well within its capabilities. The smart fuel injection technology provides smooth acceleration and response levels and I suspect the vertical exhaust stack behind the driver’s seat delivered slightly more in the way of noise feedback than is usual with an under-chassis silencer. Unless there’s a radical design change in future years, a tipper truck of any type will probably never set any diesel consumption records, however the 75.360 did deliver some respectable figures which averaged out at 10.03mpg over the three different sectors. Not a bad effort considering the altitude variations and the amount of wet surface conditions on the day. The CF posted respectable hill climb times on the brace of Perthshire ascents and the engine was happy to lug down to just a shade under 1,000rpm before requiring the next cog down. DAF’s ASTronic automated gear change system has matured well over the last few years and nowadays it’s just as capable as anything else on the market. The 12 speeds in this model were well spaced and complemented by a neatly mapped control programme. Gear changes were always slick besides being well timed and my occasional manual interventions, usually nudging the ‘box up to 12th a bit early, were in fact only about half a second in front of the CF’s intended actions. While there’s no arguing that these automated change systems will never ‘see’ the road ahead like we do, after spending a day with DAF’s ASTronic system you begin to wonder how on earth it can be improved. Perhaps installing detailed satellite tracking and real time road information such as altitude above sea level, traffic levels or current weather monitoring and data linking them to the gearbox programme? Who knows, anything’s possible. Back at the business end, a brace of type SR1132 driven axles worked away quietly and competently without any unexpected events or unacceptable noise. This pair of single reduction units were equipped with mechanical cross axle and inter axle differential locks and a maximum combined carrying capacity of 15,563kg. Staying with axles for second, the 156N type front bar has a 20mm vertical offset and is attached to parabolic leaf springs dampened by shock absorbers and stabilisers. In general the complete suspension set up was superb and the quote from my notes said ‘well up to the job’. Fully loaded tippers sometimes produce sharp momentum surges on camber changes and hill descents, but I must admit to being surprised at the lack of these encountered with the DAF CF75. Returning to the service brakes, our tipper came with the usual front disc/rear drum set up, all controlled by ABS. The parking brake is well located on the angled dashboard, just above the ASTronic selector and well out of the way from wayward feet, when crossing over internally to the passenger side. As I noted earlier, the highly effective intarder reduced service brake pedal applications substantially, but when used the left hand pedal delivered stable and trust installing stopping which was constantly easy to measure. Our test truck was fitted with a Wilcox Wilcolite 13.6 cubic metre aggregate body. At the front of this, Edbro’s CX13 gear was installed for tipping whilst an air operated tailgate and Dawbarn ‘Wraptor’ automatic sheeting kept the load space well covered. Builders Wilcox are to be applauded for the placing and accessibility of the nearside steps which give access to the load space. Unladen this body and chassis tipped the scales at 9,850kg, thereby offering a potential 16,180kg maximum payload, so there’s absolutely no concerns about this Dutchman’s profitability levels. A respite from the regular onslaught of showers was enjoyed in the eastern parts of Fife and the numerous roundabouts within the region lend themselves to a good measure of a truck’s steering and general handling abilities. On paper a 4.5 metre wheelbase chassis, with a 15.27 metre turning circle between kerbs, should offer little in the way of directional movement challenges and sure enough the CF proved to be a six wheeler that could be negotiated in the tightest of spots, whether off road or on. The 75.360 has a chunky and comfortable, soft grip steering wheel which is standard across the DAF trucks range and it delivers good feedback besides a predictable gauge. All round vision from the day cab was excellent and its slightly narrower width ensures that there’s plenty of fresh air around the rear view mirror arms, therefore minimising blind spots nicely. The four main back facing lenses proved superb and stayed clear of road spray and these were complemented by a well designed front camera system. Replacing the now compulsory ‘cleavage’ mirror, this unit is mounted nearside on the sun visor and a built in monitor screen on the angled part of the dash gave a clear picture quality. The video picture stays on at slow speeds or is activated by use of the left indicator and its safety potential grows on the driver, as you get into a viewing habit with it. DAF cabs always exude a well built feel and this is in part down to the build quality, insulation and standard fixtures and fittings. The ever popular CF range comes with three cab choices; day as tested, sleeper or space and I found plenty available room for a day’s work even in our basic two seat version. Good storage abounds above and below the windscreen area and there’s a useful lockable box on the engine cover which comes equipped with a hinged door behind two large bottle holders. I’ve got a thing about coat hanger locations and the CF scored top marks for the sturdy pair which allows jackets to hang full length in the gap behind the seats. The main dashboard is a clever mixture of six circular dials and an electronic display panel that’s easy to read in quick glances. This permits good placing of all the other ancillary switches on the angled and central dash panels and my only gripe was the position of the hazard warning switch. I think it’s too far away from the driver, particularly on a tipper motor that’ll do plenty of reversing. The £820 optional driver’s luxury air seat is a great piece of kit and if properly adjusted, will keep you fresh and free of aches all day long. Once you’re ready to depart or in fact climb back on board the CF, generous grab rails make the process of traversing the two non slip steps a easy process. At the time of writing DAF and its predecessor, Leyland DAF had led the UK truck market for 15 straight years and the CF range has undoubtedly played a major part in this success. Don’t be put off by the £120,180 price tag for this 75.360 model, as DAF has a habit of fully loading its demonstrators with every conceivable bell and whistle, to show us commercial vehicle journalists how well they all work. There’s no doubt this CF 6x4 tipper is a top quality package which offers excellent payload and earning capacity.