ROG:
Virtually all driving advice has caveats
General advice is given for what is termed as normal driving conditions
I personally would like to see far more about the use of retarders in training, I driven with several newish drivers, who have followed me down long descents, only to have screaming hot brakes at the bottom, it’s not good or safe for them to believe that retarders and gears should not be used at part of the control of speed of a truck. Especially as the bit about using more fuel is completely false, as all the manufacturers will tell you modern engine injection systems, cars or trucks, don’t put fuel in when moving with your foot off the pedal.
Good posts from Muckles.
DAF currently have (I believe) a version of the engine brake he describes, or an option of the intarder/retarder system.
The intarders work directly off the prop shaft and are most effective at high road speeds. The exhausters and engine brakes work through the engine speed and are most effective at high revs, and in lower gears.
The combination of the different systems can be very effective, and reduce the need for using the service brakes. A bit of care and you will always have cool and efficient brakes available, even with heavy loads on difficult roads.
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There is passing the test, and learning to drive professionally in all conditions. Two different things.
Im not knocking younger, inexperienced drivers, nor trainers. The training/testing system isnt designed well.
There is always be a difference between real world driving and test driving for the want of a better term. I just hope that my lessons cover the retarder etc etc as it seams to be something that could get you into serious trouble very quickly if not used correctly.
as I said somewhere (I cant remember if it was this thread or else where) I recently had an opertunity to go out as a drivers mate for a couple of hours. the lorry was a brand new daf auto that had a rotary switch on the centre console to select drive etc. next to this was a rocker switch with + and - I assumed this was for forcing the box into a higher or lower gear but im now wondering if it was a retarder. The driver used it when approaching roundabouts or traffic lights. it appeared to drop a cog as the revs would go up. I did ask him about it and the exhaust brake and he said yeah the company like us to use overrun when slowing down so I dunno
coop
cooper1203:
There is always be a difference between real world driving and test driving for the want of a better term. I just hope that my lessons cover the retarder etc etc as it seams to be something that could get you into serious trouble very quickly if not used correctly.
as I said somewhere (I cant remember if it was this thread or else where) I recently had an opertunity to go out as a drivers mate for a couple of hours. the lorry was a brand new daf auto that had a rotary switch on the centre console to select drive etc. next to this was a rocker switch with + and - I assumed this was for forcing the box into a higher or lower gear but im now wondering if it was a retarder. The driver used it when approaching roundabouts or traffic lights. it appeared to drop a cog as the revs would go up. I did ask him about it and the exhaust brake and he said yeah the company like us to use overrun when slowing down so I dunno
coop
On a newish DAF the + or - rocker switch might be to select the distance on the adaptive cruise control (ACC), but always check, never assume.
When you get behind the wheel “in anger” never be shy about asking questions. No one comes here with encyclopedic knowledge. If any trainer/instructor gets peed off by you asking questions, its because they are unsuited to their job, it aint you at fault!
cooper1203:
There is always be a difference between real world driving and test driving for the want of a better term. I just hope that my lessons cover the retarder etc etc as it seams to be something that could get you into serious trouble very quickly if not used correctly.
as I said somewhere (I cant remember if it was this thread or else where) I recently had an opertunity to go out as a drivers mate for a couple of hours. the lorry was a brand new daf auto that had a rotary switch on the centre console to select drive etc. next to this was a rocker switch with + and - I assumed this was for forcing the box into a higher or lower gear but im now wondering if it was a retarder. The driver used it when approaching roundabouts or traffic lights. it appeared to drop a cog as the revs would go up. I did ask him about it and the exhaust brake and he said yeah the company like us to use overrun when slowing down so I dunno
coop
The +/- rocker switch next to the gear selector on a Daf has nothing to do with the exhaust brake - It is, as you observed, used to manually change up/down (either to temporarily over-ride the automatic box, or when using it in manual mode). The exhaust brake on most automatic Dafs is controlled via buttons on the steering wheel.
youtube.com/watch?v=8wtdHnvLui0
Check 1min 40secs.
Is that it?
cooper1203:
daf auto that had a rotary switch on the centre console to select drive etc. next to this was a rocker switch with + and - I assumed this was for forcing the box into a higher or lower gear
Or
youtube.com/watch?v=fQSuJomyzq0
this?
it looked like this… greenhousdafbirmingham.co.u … /interior/
bad pic I know but the switch I was on about is next to the cup holders
Brakes to slow gears to go should not feature anywhere in lorry world.
Makers still go to great lengths to design retarding systems that automatically change down the gears when the retarder is switched on, to ■■■■■■ the vehicle obviously, they don’t do this because they have a few spare million euros burning a hole in their arse pocket, its for good reason.
BTSGTG is not how a professional lorry driver goes about, the proper method was explained well by Peter Smythe.
My addition to his description would be to manually select the gears as the vehicle slows using the retarder to keep it in the correct section of the rev counter for efficient retarding, this is not a one size fits all solution, each vehicle and its specific retarder should be used regularly and the best use of it learned.
Most drivers can’t be arsed or maybe have never been shown how to drive a lorry, having been taught BTSGTG police car driving techniques, you can see how they drive lorries by the inches thick brake dust on the front wheels, the difference can be hundreds of thousands of kms difference in brake wear, as well as smooth planned observed progress being both faster/efficient and more economical overall.
Driven properly harsh brakes on the open road should be rare events, you can’t count London and other big cites because idiots everywhere, so the odd sudden brake will happen if you are unfortunate enough to have to drive in hell.
Sure scares me what I hear in yards 45 year old blokes driving tippers and not knowing about the retarder or the button on automatics that set the drive system up for off road use. Most vehicles have their handbook somewhere in the cab.
Completely different thread put your seat belt on well for DAFs with auto breaking that pick up stationary trucks in lay bys you are passing or cars that are stopped to turn right. Ive had the radar turned right down and still made an automatic emergency stop