Franglais:
Plus here is a ZF clip for their “Intarder”.
youtube.com/watch?v=EKa97RYxE_Q
As an aside the best braked vehicle I had was a 2006 DAF, manual box, decent service brakes, exhaust brake and retarder.
At high road speed the intarder could drag 40ton back on a proper hill, as road speed dropped, dropping gears and using the exhauster became more effective. Service brakes stayed cool and in reserve.
A joy to drive on mountain roads and made brilliant time on the A75 over Millau.
My first MAN with a Retarder was an eye opener, it was a standalone unit driven off the back of the gearbox, but the predecessor of the Intarder, if you were too vicious in its use you could see the engine temperature rise and the warning lights would come on, it wasn’t so bad in this country but in summer in Europe it certainly warmed things up. I have seen drivers boil them up.
Wheel Nut:
Franglais:
Plus here is a ZF clip for their “Intarder”.
youtube.com/watch?v=EKa97RYxE_Q
As an aside the best braked vehicle I had was a 2006 DAF, manual box, decent service brakes, exhaust brake and retarder.
At high road speed the intarder could drag 40ton back on a proper hill, as road speed dropped, dropping gears and using the exhauster became more effective. Service brakes stayed cool and in reserve.
A joy to drive on mountain roads and made brilliant time on the A75 over Millau.
My first MAN with a Retarder was an eye opener, it was a standalone unit driven off the back of the gearbox, but the predecessor of the Intarder, if you were too vicious in its use you could see the engine temperature rise and the warning lights would come on, it wasn’t so bad in this country but in summer in Europe it certainly warmed things up. I have seen drivers boil them up.
Yes, it’s a bit weird when you have the fan coming on when you’re going downhill!!
There is a high volume of water circulating through the retarder heat exchanger in order to cool the oil, and the water temp in my old Scania will often be higher going down a steep hill than it is going up it.
I have found this post fascinating to say the very least, I am sure I am not alone when you read this thread of how it makes you realise that the older boys are actually very knowledgeable about trucks in general. I will admit in comparison I know very little about the workings of a truck with the exception of the refrigeration units. Thank you to the OP who started this thread off and the content that the real drivers have inputted. I feel like I am just a steering wheel jockey in comparison.
The Maggie dumpers used the floor button to stop engine and iirc. Ford cargo had the button on the floor as well , and from personal experience knocking an engine:exhaust on by accident a North American Volvo 07 reg going down a gravel road on snow on a mountain side is something you don’t do twice , freefalling trying to get it restarted . Still sticks in my mind , was about 10 seconds from bailing out door was open, the crew behind me thought I was gone! Luckiest I have been in 40yrs . Jimmy
Earlier in the thread I mentioned the F7/F10 butterfly exhaust brake, many will recall the reek of the engine when you fired it up in a morning and it was cold, pre night heater, most drivers fired them up and went off in search for a cup of tea. The white smoke filled the yard and our lungs, however Volvo and possibly others had thought about this problem, they fitted a switch on the dash which partially closed the butterfly enabling the engine to warm through quicker.
The switch was identical to the Diff Lock or PTO and had a safety guard to stop it being switched on by mistake. Modern thinking and speciality oils suggest we now start up and drive off immediately, older drivers would allow things to warm up and defrost the screen before driving off.
Wheel Nut:
older drivers would allow things to warm up and defrost the screen before driving off.
Some still do, and have no intention of changing 
If I really strain my brain I can imagine a piston being inhibited by compressed air, but for my purposes I am generally happy that operating the exhaust brake works quite well in slowing the vehicle down. The lovely automatics will even select an appropriate gear for me so that my day is more pleasant and I can enjoy the scenery as I proceed on my merry travels.
In all seriousness though, thinking about how they work helps us to use the auxiliary brakes more appropriately and I have learned something reading through the posts here.
Wheel Nut:
A middle aged driver may remember the exhaust brake on a Volvo F7 - F10. A button on the floor and a switch on the dash. It was orange and had a safety catch on it.
Can you explain what it was for?
White smoke limiter, this idea was also fitted to late F86 Volvos and it was a pull out round switch on the dash, if a driver wound up the mechanic it was a simple revenge, the driver struggled to get of the yard because of the lack of power, he would make his way back towards the workshop normally on foot to get one of the fitters to come and have a look, would already know what was wrong as he had been briefed, whilst the fitter jumped in to start the engine he would switch it off and ask the driver what the problem was, he would then be asked to take it for a road test and return to let him know if it was okay.
Some nasty fitters back then.
Dave 
dave docwra:
White smoke limiter, this idea was also fitted to late F86 Volvos and it was a pull out round switch on the dash, if a driver wound up the mechanic it was a simple revenge, the driver struggled to get of the yard because of the lack of power, he would make his way back towards the workshop normally on foot to get one of the fitters to come and have a look, would already know what was wrong as he had been briefed, whilst the fitter jumped in to start the engine he would switch it off and ask the driver what the problem was, he would then be asked to take it for a road test and return to let him know if it was okay.
Some nasty fitters back then.
Sounds as bad as being laughed at trying to work out how to start a V10 Merc. 
Punchy Dan:
https://www.youtube.com/watch?v=Hw13DrfR1i0
The noise gets you after a while plus it vibrates the exhaust manifold bolts loose and blows by the gaskets 
Too right very noisy but effective and banned from use in some areas of Germany through residential areas.