# Exhaust brake.



## nedrawnep (May 9, 2008)

Has anyone retro fitted an exhaust brake. Have seen several for sale on Ebay. I know how to fit it in the exhaust system; but don't know how to make it operate? Any info would be appreciated.
Thanks
Nedrawnep


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## robert b (May 9, 2008)

type exhaustbrake into google and it takes you to a page which shows you


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## Tony Lee (May 9, 2008)

Only driven buses with them and they have two main types - Jacobs type which operates the engine as an air compressor by changing the timing of the exhaust valves - which do work very well, and the butterfly valve in the exhaust pipe type which seem to be very much more variable in their efficiency. Some are so bad that you can't tell any difference when you flick the switch. I imagine the second type would be the one fitted to smaller engines. The first can result in braking of more than the rated power of the engine, the second type considerably less.

Mode of operation varies. Can have it operate only when brake pedal is pressed, or when the accelerator pedal is fully off - or either. Sometimes operate only above a certain speed and of course must disengage when the throttle is opened.

Not ever recommended for use on icy or flooded roads.


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## Tony Lee (May 9, 2008)

***** said:


> It seems to me that we are all talking about different type of vehicles
> Never mind folks
> Off to Hayfield now



Perhaps, but it all adds to our store of knowledge doesn't it.


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## Deleted member 775 (May 9, 2008)

***** said:


> Didn't know you could get these for Fiat Ducato!
> Can you
> Then it depends if they are any good as some trucks such as Volvo have excellent exhaust (engine brakes) and then others are not worth a t**s


when i worked at superdrug they got a fleet of volvo units and they had exhaust brakes fitted according to form somehow not too shure how it worked but it worked well.  something to do with preventing the exhaust valves from opening fully thus stifling the engine useful on a 45 footer  but a bit useless on a van  i would have thought as the foot brakes work perfectly well  to my mind stopping a fully loaded 30 some ton artic at 40 mph and a van at the same speed  not even worth the expense  my old beddy with drum brakes are all you need to stop a m/ home unless your dolng 70 mph


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## cas (May 9, 2008)

Theres one on Matilda but dont knoe what type


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## t&s (May 9, 2008)

exaust brakes are only for slowing down not stopping and on vehicles say under 10 ton gross i dont feel would be of any benifit the braking systems on modern vans are quite suficent i would save my money ,
if talking heavy trucks the benifit is much higher ie saving on brake re lines
and down time


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## t&s (May 9, 2008)

***** said:


> It seems to me that we are all talking about different type of vehicles
> Never mind folks
> Off to Hayfield now


have a nice weekend 
we are off to devon tonight


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## Nosha (May 11, 2008)

The only ones I see on vehicles at work are air actuated, so unless you have a vehicle with an air compressor you won't be able to activate it on the overun. The ones of little Isuzu trucks really stop you in your tracks!!


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## t&s (May 12, 2008)

how times have changed i think i might be a little behind the times 
i think they used to work in the exaust system blocking the exaust and yes may be the valve was opperated by air 
before that i think they worked on lifting the valves 
i seem to rember they were called valve lifters 
correct me if i am wrong as i would be intrested to know


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## nedrawnep (May 13, 2008)

Thanks for the info, I have a compressor as I fitted a Cargo engine in my motorhome.


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## Deleted member 207 (May 13, 2008)

The Ford Cargoes had exhaust brakes available as an option, if my memory serves me right, so I'd expect a used one would be available from a lorry wreckers to suit your engine. You would need to get all the exhaust system, wiring and air piping as well - there are usually two solenoids to cut out the exhaust brake, on the clutch and throttle pedals. All exhaust brakes have some sort of on/off switch which keeps the valve open but is over ridden by the clutch and throttle peal switches. An air supply is the usual method of controlling the valve, with electrics opening and closing the air actuators. Any competent truck mechanic could fit one to your vehicle, as long as there is space to fit it - they bolt up to the exhaust manifold where the exhaust pipes start. Bear in mind that fitting this to a non tilt cab will be harder than fitting to a truck as all work has to be done from the underside or through the cab floor. I'd say about 20 hours of labour to fit, maybe another 2 hours to iron out problems. 

Buying an aftermarket exhaust brake and expecting it to work is going to be a bit hit and miss. Exhaust brakes are designed for a particular engine - ie the volume of exhaust gas flowing through the partially closed valve - how the engine performs with the valve open, etc etc. Just by putting in a restriction in the exhaust system can have major performance problems with loss of power and increased fuel consumption. An eBay exhaust brake may not be a bargain.

Exhaust brakes are great, they certainly drop the amount of service brake usage, especially on long downhills. Contrary to popular myth they are excellent to use on loose or slippery surfaces (4x4 fire trucks in Australia have them fitted since early 1980s) - they are not ideal on ice or where there is no traction - but brakes are useless anyway.

The Jcobs Brake is a completely different method of engine braking by controlling the opening of engine exhaust valves.


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## t&s (May 18, 2008)

Roger said:


> The Ford Cargoes had exhaust brakes available as an option, if my memory serves me right, so I'd expect a used one would be available from a lorry wreckers to suit your engine. You would need to get all the exhaust system, wiring and air piping as well - there are usually two solenoids to cut out the exhaust brake, on the clutch and throttle pedals. All exhaust brakes have some sort of on/off switch which keeps the valve open but is over ridden by the clutch and throttle peal switches. An air supply is the usual method of controlling the valve, with electrics opening and closing the air actuators. Any competent truck mechanic could fit one to your vehicle, as long as there is space to fit it - they bolt up to the exhaust manifold where the exhaust pipes start. Bear in mind that fitting this to a non tilt cab will be harder than fitting to a truck as all work has to be done from the underside or through the cab floor. I'd say about 20 hours of labour to fit, maybe another 2 hours to iron out problems.
> 
> Buying an aftermarket exhaust brake and expecting it to work is going to be a bit hit and miss. Exhaust brakes are designed for a particular engine - ie the volume of exhaust gas flowing through the partially closed valve - how the engine performs with the valve open, etc etc. Just by putting in a restriction in the exhaust system can have major performance problems with loss of power and increased fuel consumption. An eBay exhaust brake may not be a bargain.
> 
> ...



ah you joged my memory a jake brake all comming back now


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## Bigmerc (May 31, 2008)

cas said:


> Theres one on Matilda but dont knoe what type



Cas its a butterfly one on the exhaust .


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