Exhaust brake/Retarder

[juddian]

10 years without a lining… thats unheard of now, respect…

I had a 14 litre with a Jake, but being an early E320 they hadn’t sorted the plumbing for all 6 so it was only fitted to 4, still miles better than any exhaust brake and only really equalled by three stage jobbies like what Volvo fit.

Interestingly my MAN exhauster loses its edge (not as its anything to write home about) around every 12 months, i notice it no longer holds speed on certain hills in certain gears, but the lads at the dealer sort it every time even on an inspection so it can’t be a massive job…possibly a decoke of the flap area or adjustment?, must remember to ask 'em next time.

[punchy_dan]

Sorry I didn’t mean to say they lasted 10 yrs .but they were good for yrs .

[weeto]

All good info from others, but here a bit about when not to use it, on slippery, wet, icy, and snow covered roads especially when empty or partially loaded, more so with volvo/renault engine braking.

[punchy_dan]

Juddian:
10 years without a lining… thats unheard of now, respect…

I had a 14 litre with a Jake, but being an early E320 they hadn’t sorted the plumbing for all 6 so it was only fitted to 4, still miles better than any exhaust brake and only really equalled by three stage jobbies like what Volvo fit.

Interestingly my MAN exhauster loses its edge (not as its anything to write home about) around every 12 months, i notice it no longer holds speed on certain hills in certain gears, but the lads at the dealer sort it every time even on an inspection so it can’t be a massive job…possibly a decoke of the flap area or adjustment?, must remember to ask 'em next time.

The only reason I can think off for having 2 heads could be where the intetcooler pipe passes over the middle head there’s not much room .

[juddian]

Punchy Dan:
Sorry I didn’t mean to say they lasted 10 yrs .but they were good for yrs .

Ah right.
I had the 401 for 3 years and it never saw a lining despite being pre limiter days and me being a young tear arse.
and yes i believe it was pots 1256 that had Jake fittings so yes it probably was intercooler pipework.

As Weeto points out you have to use the things sensibly, same as hard acceleration in slippery conditions, its the same wheels decelerating so use thy noddle, luckily on Volvo you can dial it down a bit.

Don’t ask who might have taken a strange FM out one cold morning, and didn’t notice (being a limper at the time) that the retarder was on number 3…
Don’t ask him what happened when he got to the mini roundabout 1/2 a mile from the depot and the bloody thing changed down about 3 gears… and locked the drive axle solid…
Luckily the resulting sideways route round the roundabout on black ice, complete with empty trailer adding its own snaking input to the mix, must have been comical to see and luckily got it round without hitting anything

[muckaway]

The exhaust brake on our old 02 reg CF75 was crap, until the valve thingy jammed pretty much shut on me and that brought me to a halt pretty quick. A day after my boss had found a buyer for it too.
Our CF85 8ws’ exhaust brake is very good especially since it was remapped.
Most surprisingly is our MAN TGM 6w. Only a 6.summit litre engine rated at 290 but the exhaust brake is alright if you let the revs go a bit.
Re Windrush’ post on Foden ones, the ■■■■■■■ exhaust brakes I’ve used were just hopeless.

[jimbo47]

3 stage jake on a MACK e7 engine 460 on a 3 axle tipper (ex unit) 18sp eaton. only use the service brakes when hooking up to the spreader(chips) bit of a competition going on among us to see who can go the longest without using the service brakes

[newmercman]

Proper use of an exhaust brake, compression brake or retarder is in my mind an essential part of driving a lorry. Yes disc brakes and modern friction materials have made them better than ever, but they’re always at their best when cold,so I only use the foundation brakes to stop, all my slowing down is done by reading the road and using the engine brake.

I had a C15 CAT that had a ferocious Jake brake, it turned a million miles while I had it and was still on its original brake linings, now most of the miles were done on interstates and such, but a fair few mountains were descended too, so that’s pretty good going. I could hold it on the Jake a gear and a half down from top at 2200rpms and descend a long hill at 70 mph in complete safety, this would be a long drag with nothing but open road in front of me, it would also hold it back to 20mpg on a steep mountain road, a far cry from the exhaust brakes of old that would need 2nd gear and still require a dab on the brakes to stop it running away when dropping down off a mountain on the way to Italy.

You can see and hear my Jakes in full effect on YouTube, there are a number of videos titled “Looking up a duck’s arse” I’m coming down the Rocky Mountains in at least one of them with the Jakes howling away through a pair of 6" straight pipes.

Juddian, the lack of performance you describe and the subsequent improvement will be down to a valve train adjustment done by the “technicians” they need adjusting every now and again to keep them at their best, it was something I had done regularly when I was running in the mountains all the time,the difference between a well set up engine brake and one that’s out of adjustment is night and day.

Edited because… Samsung are dyslexic children of illegitimate relationships.
Sent from my SM-T805W using Tapatalk

[juddian]

newmercman:
Juddian, the lack of performance you describe and the subsequent improvement will be down to a valve train adjustment done by the “technicians” they need adjusting every now and again to keep them at their best, it was something I had done regularly when I was running in the mountains all the time,the difference between a well set up engine brake and one that’s out of adjustment is night and day.

Edited because… Samsung are dyslexic children of illegitimate relationships.
Sent from my SM-T805W using Tapatalk

Cheers NMM, didn’t think it was too drastic as it never delays the vehicle coming back.

[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?

[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.

[juddian]

The last part of Evil’s OP mentioned this not being part of training and testing.

TBH training is now concentrated into such a short period there really isn’t time to teach lorry driving finesse such as this.

My course was 10 days in '76, which was about normal though that was straight to class 1, there was time to teach lorry driving, and dare i say it there appeared to be lots of emphasis on the driver being in charge of the vehicle then.
Many lorries of the day didn’t have exhaust brakes or other retarders, and the training vehicles were no exception, but using the gears correctly for slowing, indeed being in the correct gear at all times, was very much instilled from the moment you climbed into the drivers seat.
I don’t see an answer to this in modern training in the timeframe, but have no doubt the pro trainers would love to have 10 days with each trainee and could cover lots more, including some intensive maneuvering so so many poor buggers wouldn’t dread having to get in places in their first few months out on their own.

On my first DCPC course (my company dropped them quickly, but not for this reason), the trainer who said he was a lorry instructor too, waxed on and on about brakes to slow gears to go and how good modern brakes were so appropriate gear braking no longer needed, after about the tenth time of hearing this claptrap i had to have a go about it pointing out the pitfalls etc…not great that newer drivers should be taught ■■■■■■■■ like that from someone who they would assume would know whats best practice.

Luckily we have this place where we can discuss things, its good for all of us, us old uns can learn new tricks and newer drivers can pick up tips if they, as shown here, have the nous to put them up for discussion.

Good thread.

[windrush]

I did my training in '76 the same as Juddian in a 1968 Foden eight wheeler (only a mundane class 2 though, sorry you class 1 lads ) and was taught the same way of braking using gears and engine. The truck would only do 38 mph in direct top so speeding wasn’t really a problem but you still had to stop it! I remember many years ago seeing an article by Mercedes Benz about the factories recommended way of driving for economy and smoothness in one of their trucks which was to get into top gear as soon as possible and approach road junctions by staying in top as long as possible and coasting up to the junction with the clutch depressed as gearchanges wasted fuel.

Another thing regarding brake fade etc was ignorance on the driver’s part, some assumed that when their service brakes were overheated and useless they still had a secondary system to stop them, they were not aware that both systems used the same brake linings and drums!

Pete.

[actrosman]

tommymanc:

merc0447:
I still use it but not the same extent as its good to show brake lights on approach to junctions.

I’ve always wondered this, so the Exhust brake will actually turn the lights on without touching the pedal?

We were told (by a ‘suit’ from MBUK) that by yanking on the retarder/engine/exhaust brake stalk on our Merc’s that it would indeed illuminate the brake lights…on ours, it doesn’t and has nearly come to a messy ending on a few occasions whilst holding back at 90km in stage 2, worse when stage 3 as it drops a gear to increase the revs and knobber behind is to close and isn’t paying attention. At least it works, unlike my old Scania!

[robroy]

Actrosman:

tommymanc:

merc0447:
I still use it but not the same extent as its good to show brake lights on approach to junctions.

I’ve always wondered this, so the Exhust brake will actually turn the lights on without touching the pedal?

We were told (by a ‘suit’ from MBUK) that by yanking on the retarder/engine/exhaust brake stalk on our Merc’s that it would indeed illuminate the brake lights…on ours, it doesn’t and has nearly come to a messy ending on a few occasions whilst holding back at 90km in stage 2, worse when stage 3 as it drops a gear to increase the revs and knobber behind is to close and isn’t paying attention. At least it works, unlike my old Scania!

As far as I know the exhauster has never activated brake lights.
I often use it to discourage tailgaters, especially the Billy Bigbollock type of supertrucker (usually in a tipper) trying to push me over the speed limit to save at least 2 seconds on his very tight schedule
Their reactions seem to prove this.

[shep532]

I have come across some exhaust brakes that operate the brake lights but can’t remember which trucks. It’d be a good idea if they all did.

I know there are devices you can buy that operate the brake lights if you decelerate by more than a given rate. Mainly intended for motorbikes where a rapid downchamge of gear can create very quick deceleration with no visible warning to those behind. With today’s technology can’t be hard to do.

I made a note this morning to watch brake lights on trucks in N/S lane. All those travelling too close together were regular brake lighters - brake lights on for a few seconds, then a few seconds later on again which then tended to send a ripple down the line. They clearly don’t have an exhaust brake or the ability to simply leave their foot off the throttle or even knock it down a gear for extra engine braking.

[robroy]

I have an Actros, I was told that less fuel is used if you regulate the speed on the button on the steering wheel rather than the throttle pedal.
Now I don’t know if this is true or b/s, and even if it is true, I would imagine the difference is minute bordering on negligible.

I tend to do all of the above techniques stated in this thread (never used to, I did not give a toss once over tbh)
My driving technique has changed considerably since getting the Actros with the fleetboard system. …Not because I am pandering to pressure, or trying to be a good boy for the teacher, more to prove a point to one or two of the smartarses on the fleet who THINK they are drivers.
I am deffo doing something right as I am in the top 2 of my depot of 30+ every month…in fact I’m just too ■■■■ good to be true. not to mention modest.

But seriously though , …I have changed my opinion on these driving performance monitoring systems.
The fitting of these do have the desired effect of saving fuel/wear and tear etc…albeit in my case for a different reason, but I suppose from the firm’s point of view the result justifies the means and motive.

Edit…What a knob I meant to put this on the fuel saving thread

[dipper_dave]

Tempted as I am to put this reply on the fuel saving thread to balance things out I aint that daft
Now I havent had chance to read all this thread so will just agree with everything Juddian has posted to be on the safe side.

Now for noobs like the evilnizzmaister one must first picture what the exhaust brake is doing in relation to your outfit, im talking bendys not class poos here, in fact our class ■■■ members may want to tackle indicating first before an advanced topic such as this…

Right so exhaust brakes and other engine retardation devices reduce the speed of the traction unit only well they dont this is a secondary feature but thats being pedantic, correct use will be down to the individual but as a rule of thumb to drive a large vehicle one must do so in a flowing gracefull manner, useing speed and forward planning to make progress. Saving brakes unless ■■■■■■■ go skyward by operation of the exhaust brake is a natural way to reduce speed and this helps with a plethora of road scenarios. But remember youve still got 3x your unit weight pushing you along so balancing exhaust brake use with service brakes can work wonders. Be wary of excessive ehaust brake use in slippery and icey conditions or at times of instability.

Now my little Renault has 3 settings on the exhaust brake.
Setting 1 kills cruise and is ideal for noshing a bit of speed off due to prevailing conditions, like a merging vehicle, slowing vehicle, creating a bit of space to the vehicle in front etc.
Although its very weak so opening both windows can have a similar affect.

Setting 2 is a bit more beefy and ideal to back her off on gradients to let a fellow sister pass who is bottling it or not quite as heavy.

Setting 3, Now were talking, the speed reduction affect of this is akin to deploying a pair of the wifes under crackers like she lends out for land speed tests. The truck if an auto will also downshift to give full reverse thrust (its not really reverse thrust but thats what I call it).

So in essence correct and appropriate use of of secondary raking devices comes with time and experience, to heavy on it in icy conditions and you could be in the poop.

Remember where safe to do so, save your brakes coz they will save you.

Oh and dont leave the bloody thing on as its a bit embarrasing on roundabouts.

Oh and dont be one of these nob jockeys who put the bloody thing on when manouvering coz it sounds cool.

[muckles]

robroy:

tommymanc:
I’ve always wondered this, so the Exhust brake will actually turn the lights on without touching the pedal?

As far as I know the exhauster has never activated brake lights.

The FH I drove would operate the brake lights, not sure if it only did it when the lever was at 3 (max braking), or at a certain rate of deceleration.

However I believe the Volvo system also works using the exhaust valve, I think similar to a Jake Brake. Which is probably why many people here have mentioned the Volvo and Renault systems power.
I’ve noticed the difference in my new job driving an Actros and that isn’t anywhere near as good on long descent or long climbs.

[punchy_dan]

I’ve read somewhere that Jacobs have made a engine brake for Mercedes lorries .