Button on the floor you stand on.
Also there is a switch on the dash that looks like a circle in between a pair of brackets, turn this on and leave it on all the time.
If it has a retarder, I believe that should be on the Opticruise stalk, but I stand to be corrected on that.
Button on the floor ? Oo
I will have a look, cheers. And yes, the auto exhauster has already been identified 
thanks a lot 
One of these works just fine
Taxi
found the button, it actually is right in the middle of the floor. i initially thought it was there to hold the mat from sliding
thanks again 
I’ve driven these vehicles and never realised that. The first truck I drove with a floor button was a 7.5T Merc and the button was used to stall the truck so you could turn the ignition off - you couldn’t just turn the key. I’ve used that button on the dashboard and wondered why it didn’t ■■■■■■when you came off the gas, only when you pushed the brake pedal down.
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Yes I had an old Iveco Eurocargo with the floor mounted stall switch. The Scania exhaust brake is basically useless unless you get on it really early in practical terms. It does however greatly improve your driver score.
Yeah, at the moment i find the regular lever type exhaust break easier to use.
Stall swithc? Oo zb me, so there are trucks you ned to press ut to stop the eng8ne? 
Priest:
Yeah, at the moment i find the regular lever type exhaust break easier to use.Stall swithc? Oo zb me, so there are trucks you ned to press ut to stop the eng8ne?
Like anything it becomes second nature the more you do it.
As for stall switches, I haven’t seen one for a long time. Last truck I had with one fitted was registered in 1997
I always thought r series exhaust brake was on the first stage of the brake pedal