theres a video here telling you how to operate the volvo retarder
interactiveoverview.volvotrucks. … lama=en-gb
in the daf, the needle should be in the blue band for the ehaust brake to be silightly beter than pish 
Sir +:
■■■■■■00:
Always wondered that when you use the exhaust/retarde brake, do your rear brake lights come on. stupid question you may think but its an answer to a question i have often wondered.No stupid questions,only stupid answers.I hope this isn’t one
No brake lights with an exhaust brake.Hydraulic retarders AFAIK don’t have that option.Telma electric retarders I think may have had that as an option.
On an Actros the exhaust/engine brake puts the brake lights on, also ABS disengages both if its triggered, just a shame the exhaust brake ain’t that brilliant at slowing the truck down when fully laden 
Wheel Nut:
Sam Millar:
It alters valve timing.How does it do that Sam, it would bend the valves
Ah wait, I’m getting mixed up with engine braking mate sorry.
Wheel Nut:
How does it do that Sam, it would bend the valves
Sams right, on engine brakes the exhaust valve opens just after TDC so the air that been squashed on the compression stroke is allowed to escape instead of pushing the piston away again.
Mikey D:
Ive got a Jake brake on my cat engined, Foden . Great soundand really effective too
. and now thanks to trucknet i know how it works
Me too. A better system than any on our Dafs and Volvos, and great fun when going through towns as it startles kids, coffin dodgers, animals etc…
Do any manufacturers still offer the Jake now Fodens have finished?
Big Joe:
Wheel Nut:
How does it do that Sam, it would bend the valvesSams right, on engine brakes the exhaust valve opens just after TDC so the air that been squashed on the compression stroke is allowed to escape instead of pushing the piston away again.
and it wont bend the valves cos it desinged that way
Big Joe:
Sir +:
■■■■■■00:
Always wondered that when you use the exhaust/retarde brake, do your rear brake lights come on. stupid question you may think but its an answer to a question i have often wondered.No stupid questions,only stupid answers.I hope this isn’t one
On an Actros the exhaust/engine brake puts the brake lights on, also ABS disengages both if its triggered, just a shame the exhaust brake ain’t that brilliant at slowing the truck down when fully laden
DAF also puts brake lights on using the useless noise changer that should be an exhaust brake.
Seen the brake lights reflecting off signs behind me, so it is a silly question if you’re incapable of using your mirrors
Enlightening, from this info i would assume that the MAN trucks also have a jake brake, as they also have a good exhaust/engine brake, those Volvos are grate fun bobtail in the wet, had the real wheels lock with it set to max, (i forgot to adjust it) as i was fully freighted on the outward part of my trip,
I can remember a few years ago some of the lads used to rev the engine with exhaust brake on , it would make a muffled sound and upon release of the brake it would emit a plume of thick black sooty smoke,lol
they would brag about smoking out the French whilst stopped at traffic lights , I’m thinking they where lucky that the gendarme’s didn’t clock them doing it,
Sir +:
■■■■■■00:
Always wondered that when you use the exhaust/retarde brake, do your rear brake lights come on. stupid question you may think but its an answer to a question i have often wondered.No stupid questions,only stupid answers.I hope this isn’t one
My 08 plate r420 scania does. When I press the exhaust brake button in the middle of the floor (which you need to be disabled with odd legs to use comfortably!) it activates the brake lights, and the 09 plate fh480 Volvo also set the brake lights off when I used the excellent exhaust brake.
Muckaway:
Mikey D:
Ive got a Jake brake on my cat engined, Foden . Great soundMe too. A better system than any on our Dafs and Volvos, and great fun when going through towns as it startles kids, coffin dodgers, animals etc…
Do any manufacturers still offer the Jake now Fodens have finished?
As I said above, the Jacobs or Jake brake is named after its manufacturer.
It does exactly the same as the engine brake fitted to Volvo and DAF engines and they all work the same way,ie releasing the engine compression at the top of the compression stroke.
Before anyone says the DAF exhaust brake is crap, yes it is, but you can specify the DAF engine brake as an extra, it works in the same way as the Volvo.
I once had a MAN/ERF horrible thing with a 385 ■■■■■■■■ this also had a very effective engine brake and a very ineffective exhaust brake.
They are all versions of engine brakes or compression release engine brakes.
EDIT. How effective they are is directly related to the size of the engine in relation to the weight of the truck, so if you have a six or eight wheel rigid with 12 or 13 litre engine, the effect will be much more than on a 44 tonne artic with the same sized engine.
Regards,
Nick.
Sir +:
■■■■■■00:
Always wondered that when you use the exhaust/retarde brake, do your rear brake lights come on. stupid question you may think but its an answer to a question i have often wondered.No stupid questions,only stupid answers.I hope this isn’t one
on my 4 series scanny the retarder puts the brake lights on, and if i pull the lever down to max it knocks the exhaust brake on aswell 
I don’t think my R420 uses brake lights with the retarder, I usually leave it set on auto level 1 and it works when you lift off the throttle. General tootling about it does most of the brake work. On max it’ll slow me down well even fully freighted barrelling down the M20 hills without touching the brakes.
I think the only Butterfly exhaust brake that did work was a DAF, at least it stopped the engine 
Wheel Nut:
I think the only Butterfly exhaust brake that did work was a DAF, at least it stopped the engine
It did that, but little else, you’d get more retardation by holding your hat out of the window
Exhaust brakes need lots of revs and then don’t do much, they’re better than nothing, but only just. on the other hand, engine brakes are much better, my Jake Brake does 90% of my braking and through straight pipes it sounds awesome 
cieranc:
manowar:
Intruiging, I didn’t realise Volvo’s had the engine brake which works by venting the cylinder after the compression stroke. I was told that design was too loud for road use. Perhaps I was hearing some drivers diesel fumesYeah that type is a Jakobs brake (Jake Brake). I didn’t think they were allowed here either, for the noise reason. Even in America theres some states where their use is not permitted.
I’ll ask my mate Barrel, he works at the dealers.
Jake brakes are prohibited in most residential areas of PA and other states such as VT. There are a few Interstate sections where they are banned also. My old Columbia had a Merc engine with a very quiet exhaust brake and even in such prohibited areas I used it without any trouble. My bew truck has a Detroit DD15 with a jake brake that is much more powerfull but almost as quiet as the merc.
Engine brake related and a little bit funny, posted before, but good enough to be repeated
Wheel Nut:
Sam Millar:
It alters valve timing.How does it do that Sam, it would bend the valves
205:
Big Joe:
Wheel Nut:
How does it do that Sam, it would bend the valvesSams right, on engine brakes the exhaust valve opens just after TDC so the air that been squashed on the compression stroke is allowed to escape instead of pushing the piston away again.
and it wont bend the valves cos it desinged that way
Quite so, its not a car engine with no tolerance between an open valve and a piston at TDC.
But they’re not being opened with pistons at TDC, so it wouldn’t anyway.
Wheel Nut:
I think the only Butterfly exhaust brake that did work was a DAF, at least it stopped the engine
… and so it did on an F88 that went over the side of the Blanc in the early 80’s. Driver broke his arm bailing out.
cieranc:
Just a flap in the exhaust pipe, that when closed, restricts the exhaust gas flow. If the exhaust can’t flow, the engine gets choked, resulting in more engine braking.Then there’s the Jake brake engine brake, which alters the valve timing to turn the engine into a huge compressor. Makes a sound like a machine gun.
Or the torque converter type retarder that just squishes oil between gears to create drag on the transmission.
Or the electric engine brake, which is in effect a huge motor on the propshaft. This causes drag on the prop to ■■■■■■ the transmission.
Since i read the header,2 hour ago i was thinking how to explain it without taking my Dictionary from anywhere it is.
well,You did it very well.Couldn’t have done it better.