That could be true as the new in-line engines in Mercs are Detroit Diesels. Over here in the colonies Jake Brake has become the generic word for an engine brake, I even refer to the engine brake on my Volvo as a Jake, so it could also be that the generic term is being used to describe the engine brake on the Merc/Detroit engine. The old Vee engined Mercs used a similar set up but it was known as the Konstantdrossel, which is German for constant throttle.
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Punchy Dan:
I’ve read somewhere that Jacobs have made a engine brake for Mercedes lorries .
Cool… I lurve their Cream Crackers! 
proper trucks have a telma 
Scania have put the button in the wrong place. If you switch it on it does come on with the footbrake though. I can get a good driver score like this, without ever using the floor control.
At one time the exhaust brake on Fodens with the Rolls engine worked on the first part of the footbrake pedal (this function could be turned off though if the driver didn’t want to use it) and therefore the brake lights did come on. However the system wasn’t a great success and a seperate button on the floor was fitted. The brake lights also worked with the parking brake.
Pete.
I reckon that there aint too many on here that remember the foot operated button on car floors to dip head lights, but here goes.
In the early 80s I knew a guy who drove a Dodge tractor unit that had no exhauster fitted, so he had never came across them until he got a Volvo 88 on demo.
He brought it back to the yard first day early morning, with a ‘fault’…‘‘Everytime he tried to dip the headlights, it made a noise and slowed down’’…I kid you not.
robroy:
I reckon that there aint too many on here that remember the foot operated button on car floors to dip head lights, but here goes.
In the early 80s I knew a guy who drove a Dodge tractor unit that had no exhauster fitted, so he had never came across them until he got a Volvo 88 on demo.
He brought it back to the yard first day early morning, with a ‘fault’…‘‘Everytime he tried to dip the headlights, it made a noise and slowed down’’…I kid you not.
Yes I for remember them and you’ve got to be joking ?
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My Hillman Minx had a foot operated dipswitch, i liked them, can’t remember where it was on me first car though, Volvo 122s Amazon.
Regarding brake lights coming on with exhausters, like everything one size doesn’t fit all/
Makes me laugh when you use the exhauster in a high mileage Scanny and all it does is makes a noise and thats it, yet the brake lights come on.
I like the fact the one in MAN’s doesn’t light 'em up.
As mentioned previously they should only come on when a certain rate of deceleration is reached, brake lights should mean business not coming on all the bloody time cos people get de-sensitised and then when all hell breaks loose and we’re all on a full panic stop people don’t respond till its too late.
My own view is that high level brake lights fitted to all vehicles should only work when high deceleration is detected, same reasoning.
htmldude:
Punchy Dan:
I’ve taken the exhaust brakes off both my lorries ,they’re like chocolate fire guards ,both have the jacobs engine brake instead on all 6 cylinders .Well a jake brake > exhaust brake, but one is more common than the other.
Sorry you’ll have to explain .
Bluey Circles:
A question on exhaust & Jakes: I’m thinking, Exhaust brakes work by holding the pressure in the manifold, Jakes work by holding the pressure in the cylinder by delaying the opening of the exhaust valve ? how do they delay the opening of the valves on the jake?
Beep - thought I would give this question another airing, just in case.
Bluey Circles:
Bluey Circles:
A question on exhaust & Jakes: I’m thinking, Exhaust brakes work by holding the pressure in the manifold, Jakes work by holding the pressure in the cylinder by delaying the opening of the exhaust valve ? how do they delay the opening of the valves on the jake?Beep - thought I would give this question another airing, just in case.
Hope this helps, haven’t watched all the way through myself yet.
Bluey Circles:
Bluey Circles:
A question on exhaust & Jakes: I’m thinking, Exhaust brakes work by holding the pressure in the manifold, Jakes work by holding the pressure in the cylinder by delaying the opening of the exhaust valve ? how do they delay the opening of the valves on the jake?Beep - thought I would give this question another airing, just in case.
If you ever had a 2 stroke motorbike like a villiers powered one with a decompressor on then that’s it ,on top of the engine cylinder heads are the rocker tops then another casting about 2/3 inches deep goes on again it has electric solenoids that when opened use engine oil pressure to hold the exhaust valves open other than on the exhaust stroke .
I’ve driven modern lorries and application of the “retarder” (they no longer call it just an exhaust brake as it has an additional computer function over an exhaust that simultaneously drops gears for compression compared to the old rubber air button on the floor). I noticed the tail lights illuminated below 40 in deceleration on this unit.
The only reason fuel is lost in decelerating on modern vehicles (where fuel is cut off when engine braking) is that kintetic energy lost through heat and noise in braking has to be regained again by fuel burn to accelerate back up to speed. You brake and it’s more coals on the fire to get back to speed. The same with retarders. A lot of people don’t get the concept of harsh braking burning fuel, they incorrectly think it has something to do with actually burning fuel whilst braking. It’s energy management.
Do retarders still carry a hefty weight penalty? I remember reading Trucking mag years ago featuring Smiths of Gloucester with some Renault Maxters; It said the weight was the reason tippsr firms didn’t buy them. 250kg was the figure I think.
Punchy Dan:
Bluey Circles:
A question on exhaust & Jakes: I’m thinking, Exhaust brakes work by holding the pressure in the manifold, Jakes work by holding the pressure in the cylinder by delaying the opening of the exhaust valve ? how do they delay the opening of the valves on the jake?If you ever had a 2 stroke motorbike like a villiers powered one with a decompressor on then that’s it ,on top of the engine cylinder heads are the rocker tops then another casting about 2/3 inches deep goes on again it has electric solenoids that when opened use engine oil pressure to hold the exhaust valves open other than on the exhaust stroke .
So a Jake is not truly an exhaust brake, it simply opens the exhaust valve at the top of the compression stroke and wastes the compressed air that would have otherwise forced the piston back down. I had always thought the Jake withheld the gas on the exhaust stroke but somehow held it in the cylinder rather than the manifold as per the exhaust brake - learn something everyday in trucknet.
I thought this lad explained it quite well.
Freight Dog:
I’ve driven modern lorries and application of the “retarder” (they no longer call it just an exhaust brake as it has an additional computer function over an exhaust that simultaneously drops gears for compression compared to the old rubber air button on the floor).
a retarder is not an exhaust brake. don’t know too much about other makes, but the retarder on a scania is hydraulic and with a heavy load and high speed rolling donhill, it’s possible to get the oil in it to boil, it then shuts off
milodon:
Freight Dog:
I’ve driven modern lorries and application of the “retarder” (they no longer call it just an exhaust brake as it has an additional computer function over an exhaust that simultaneously drops gears for compression compared to the old rubber air button on the floor).a retarder is not an exhaust brake. don’t know too much about other makes, but the retarder on a scania is hydraulic and with a heavy load and high speed rolling donhill, it’s possible to get the oil in it to boil, it then shuts off
Yeah, just when you need it most.! Some have a cooling system, but I don’t know how well they work.
I see in F1 they are using electric generators as retarders, storing the energy in a battery then reusing it to power the vehicle. I am surprised no one is going down this route with trucks, may be store all that compressed air generated by the jake and then put it back into use.
Muckaway:
Do retarders still carry a hefty weight penalty? I remember reading Trucking mag years ago featuring Smiths of Gloucester with some Renault Maxters; It said the weight was the reason tippsr firms didn’t buy them. 250kg was the figure I think.
Not sure really Nathan, never had dealings with them but they were generally considered too heavy for most rigid tipper work as the figure you mention (about 1/4 ton in Old English!) ate into the payload drastically. They worked well though but an extra 1/4 ton every load would pay for a lot of brake linings!
Pete.
Bluey Circles:
I see in F1 they are using electric generators as retarders, storing the energy in a battery then reusing it to power the vehicle. I am surprised no one is going down this route with trucks, may be store all that compressed air generated by the jake and then put it back into use.
Stobarts are running some trailers with this built into the middle axle. During normal use the axle drives and helps the tractor thereby saving fuel - during coasting or braking the motors charge accumulators which in effect also brakes the trailer without the wear and tear of normal brakes - all F1 type technology. Saw one on display at the CV show - built by SDC.
Some retarders control the inlet and exhaust valves on the engine along with variable valve timing meaning the engine can be turned into a compressor to give enhanced engine braking. This in turn increases the combustion chamber temperature which means when fuel is reintroduced it burns better and therefore less is needed. Combined with a regular exhaust brake these complete systems can be very effective.