I’m still learning the ropes so to speak,
Do leave your exhaust brake on when pulling an empty trailer?
Do you just turn it off when driving unit only (bobtail)?
Also ? on tag axles and midlifts,
when trailer is empty and you are dropping or hooking axles up or down?
Am I right in always having axles down when dropping/hooking laden trailers?
Sorry about all the 
's
thanks for any help.
From my experience all makes of truck are different so your question re leaving exhast brake on is to go by the feel of it. Volvo one is very efficient, so may be best off.
most trucks with lifting axles have weight sensor built in, so when picking up a loaded trailer, the axle wil come down automatically, dependant on how high trailer has been dropped, ie how much of it’s weight is applied to unit before you start lowerring legs. Always prefer to run in with axles down, but that is personal. Sometimes with mid lift, and low profiles you might not be able to ‘lock’ onto trailer without raising mid axle, as can lift chasis a little which might help.
Hope this helps
Volvo’s n Scanies have a switch for the exhauster, normally I leave it on loaded, empty or solo. If its wet or slippery for some reason, then I knock it off when solo, so that the back axle won’t step out when the auto exhauster kicks in.
As for hooking up or dropping trailers, I normally have all the axles down, and then lift, or not, to suit the trailers load.
No probs with you asking for help, thats one of the things we’re here for. 
Some exhaust brakes are excellent, some are a waste of space, others lie in between. Try each one out on each motor as they can differ between even similar motors.
It would be nice if trucks actually had exhaust brakes that actually made a difference when fully loaded.
I thought you only turned the exhaust brake on when you want to slow down?? 
I only use mine when loaded, the noise gets on my ■■■■!
removalboy:
I thought you only turned the exhaust brake on when you want to slow down??
they can be switched on all the time because you never know when you might need them - it does no harm to do that.
HOWEVER - especially for C+Es - there are certain situations where the use of exhaust brakes is definitely not recommended such as going down a slippery hill - the exhaust brakes only slow down the unit and not the trailer so going down a slippery hill may cause the trailer to try and overtake the unit
PS - by Big Truck » Sat Nov 01, 2003 4:58 pm 
ROG:
removalboy:
I thought you only turned the exhaust brake on when you want to slow down??they can be switched on all the time because you never know when you might need them - it does no harm to do that.
But surely it slows you down when accelerating?
ROG:
removalboy:
I thought you only turned the exhaust brake on when you want to slow down??they can be switched on all the time because you never know when you might need them - it does no harm to do that.
HOWEVER - especially for C+Es - there are certain situations where the use of exhaust brakes is definitely not recommended such as going down a slippery hill - the exhaust brakes only slow down the unit and not the trailer so going down a slippery hill may cause the trailer to try and overtake the unit
PS - by Big Truck » Sat Nov 01, 2003 4:58 pm
Which means they only put all the retardation forces through the drive axle/s not any other axles on the unit because they work together with engine braking.Which is another reason why the yanks (rightly) like double drive/6x4 units because a jake brake is even more effective in magnifying engine braking forces.The reality of a trailer trying to overtake a unit in that situation of a locked/slipping drive axle would probably mean a jacknife.But having said that engine braking down hill is just as important as braking to avoid frying the brakes.But for some reason no one thinks of all that when they specify 6x2 or 4x2 tractor units.
Yeah, that’s some impressive digging to find this old thread!
With exhaust brakes, I find that it’s just a case of what you get comfortable with using. Having driven volvos the majority of the time, the automatic exhaust brake just becomes part of the driving style, and you feel something’s missing when you end up with a vehicle that doesn’t have it, or you get into your truck to find that someone else has used it and turned it off!! All the volvos I’ve driven, all the exhaust brakes have been effective but quite subtle in their operation, but it definitely depends on the engine (the 12 litre is definitely way better than the 7 or 6)
i used to drive a scania 6x2 4series and i kepy my axle up all the time unless it dropped on its own !!
ie; if i pick up a load an axle doesnt drop then i leave it up as i feel i get alot more traction,
also i left the exhaust brake on as the brakes never felt great to me even though it passed mot etc etc numerous valves later an full re-line they stil felt the same so the exhaust brake helped me, although it made a very loud whistling noise it still worked
What can I say, I’m trying to win the comprtition Cruise Control started 
removalboy:
ROG:
removalboy:
I thought you only turned the exhaust brake on when you want to slow down??they can be switched on all the time because you never know when you might need them - it does no harm to do that.
But surely it slows you down when accelerating?
No. Although it’s switched on all the time, when your foot is on the loud pedal the Ex brake switches to standby mode
Steve-o:
removalboy:
ROG:
removalboy:
I thought you only turned the exhaust brake on when you want to slow down??they can be switched on all the time because you never know when you might need them - it does no harm to do that.
But surely it slows you down when accelerating?
No. Although it’s switched on all the time, when your foot is on the loud pedal the Ex brake switches to standby mode
That’s true, the automatic exhaust brakes are all on fly-by-wire systems, so when your foot is on the accelerator it’s off, when the revs fall below a certain threshold they turn off (stops the engine from stalling. Stomped on the floor button on an old DAF a few weeks back whilst idling in the yard and the engine promptly died.) and when you’ve got your foot on the clutch, they’re off.
Steve-o:
removalboy:
ROG:
removalboy:
I thought you only turned the exhaust brake on when you want to slow down??they can be switched on all the time because you never know when you might need them - it does no harm to do that.
But surely it slows you down when accelerating?
No. Although it’s switched on all the time, when your foot is on the loud pedal the Ex brake switches to standby mode
Clever, should have known 
the man auto im driving at the moment has an automatic exhaust brake…it comes on when you brake,and if you are on cruise control and it rolls away on downhills it drops itself down a gear,sometimes 2 and puts the exhaust brake on to pull your speed back down.
it does have a switch to stop it working,the manual reccomends switching it off in slippery conditions(ice or snow)and of course the off switch is vital for all those who feel it is a sin not to roll down hills as fast as possible.
Different vehicles may have exhaust brakes that are good,bad or indifferent,but on all types,they are more effective at a higher engine speed.
There are many factors affecting the affectivenes of exhaust brakes.It can be that some manufacturers have not quite managed to design the best installation,which is why some marques are better than others for a similar engine size.
Then engine size has a big effect,that on a 12 litre will be far superior to that on a 7 litre.
Then there is how a driver uses what he’s got.
On most trucks,the rev counter has a green sector for the most economic,maximum torque situation,but may also have a yellow band before the red maximum rev indicator.
The exhaust brake will give its best performance in this yellow band.
On Volvos,the exhaust brake comes on at a low setting on the first movement of the footbrake,then there is the upper stalk on the right of the steering column that has three levels of effectiveness that can be used.
On many vehicles when running on cruise control,in the event of a couple of klicks overspeed,the exhaust brake comes on automatically,then drops out again when your speed drops.
On any vehicle that has the exhaust brake manually switched on all the time,it is overridden when the accelerator is pressed but comes in as soon as the accelerator is lifted,giving a degree of automatic braking.
On automatics,just using the exhaust brake you will find that the box changes down quickly to keep the engine speed in the yellow band of the rev counter.
Common sense is required when running light or bobtail in bad weather.
As stated,the exhaust brake has more braking effect at high revs but only on the drive axle(s). Therefore,if full retardation is used,although it may not stop the wheels of the drive axle(s) turning altogether,it may slow them down quickly enough to prompt a rear axle skid if solo,or a jack knife if you have a trailer on.
I think there is a lot of confusion when people are talking exhaust brakes. As Ian mentioned the yellow band is the best sector to use them in as this offers more retardation.
A true exhaust brake is a butterfly valve operated by a pneumatic cylinder across the exhaust manifold outlet. they restrict the gas flow and build up pressure in the engine. The reason the DAF stopped is that it was also designed as the Engine Stop button, previously we used a cable stop control until those clever buggers from ■■■■■■■ designed a diesel pump with an electric solenoid.
Carryfast mentioned a JAKE brake, now a generic term for a Compression Brake, designed by Jacobs. This is a mechanical brake working again on the engine but driven using the camshaft, instead of restricting the gas pressure in the exhaust manifold it releases the building pressure in the cylinders.
Another retarder is the gearbox retarder where they use either electro magnetic forces or steel bands that can slow the engine, then there are Telma types. Voith propshaft retarders
Older drivers will remember the Spanish trailers with a Diff on the back axle, this had a disc attached and slowed the truck using an extra set of brake pads, similar to an old TK Bedford handbrake No backlash please
They all do a similar thing, some do it much better, some are very noisy in operation, some make the lorry engine overheat as they use the engine radiator to cool them. Apart from the simple butterfly valve they are all heavy. Most have switches on clutch, and accelerator linkage to knock them off when either is used.
Most of these on modern vehicles can be coupled to the automatic gearbox & cruise control leaving the driver to steer the vehicle, put fuel in it and pick his nose. 
allikat:
Some exhaust brakes are excellent, some are a waste of space, others lie in between. Try each one out on each motor as they can differ between even similar motors.
had fun with mine last week (DAF) it got stuck ON - never knew it was that effective before