Exhaust Brake - When to Turn On

[1ciderdog]

Originally Posted by MSHappyCampers

I leave my exhaust brake on all the time. It is activated when I press the brake pedal for a second or two. It turns off when I press the throttle.

That's the way my Winnebago 39K was set up. Worked well that way.

[Ray,IN]

Originally Posted by NevadaNick

Only turn it on when needed, otherwise you will burn more fuel.

That's my thinking also, leaving it on eliminates coasting.

[Dav L]

So, for the folks that leave the ebrake on all the time...what's the normal driving?

Cruise down i80...car in front is slowing down. Lift accelerator...eBrake engages. Tap the accel to coast. Car speeds back up, push the accel again?

That seems more busy more of the time then just lift the accel and coast. It's On or Brake. No On / Coast / Brake option.

[Fred Cooper]

A lot of good information and differing opinions...which is all good.


I think use of the exhaust brake is a personal decision based on your preference along with how your coach manufacturer programmed the exhaust brake. I prefer to have it off unless I am headed down a significant incline.



Several of the posts imply that having the exhaust brake on provides shorter stopping distance in a panic stop. I do not believe this actually helps.



I asked this question at a Freightliner Technical workshop, and got the answer that for a panic stop, the coach service brakes provide the maximum stopping power (antilock brakes) and the exhaust brake will not help.



The coach that we had, (2000 HR Endeavor Freightliner chassis) if I had the exhaust brake on while cruising down the highway, and encountered a sudden panic stop, the system brakes would be near lockup one or two seconds before the exhaust brake would engage, and the exhaust brake would contribute nothing to the panic stop.


As far a saving the brake lining by using the exhaust brake, our coach at 112,000 miles still had significant brake lining left.



Your opinion may differ.


Fred

[Poppy01]

This article refers to the use of a Jake Brake, not an exhaust brake. Using an exhaust brake used the same amount on fuel as coasting. My accelerator on my coach has just enough 'play' that I can just touch it and it releases the exhaust brake. I can coast all the way down the hill if I want, engage the exhaust brake off and on without touching the switch.

I leave mine on except when the cruise control is set.

Originally Posted by NevadaNick

I’m not telling anyone how to use it, i’m just saying you will use more fuel.
https://www.teamrunsmart.com/article...kes-waste-fuel

[NevadaNick]

Exhaust brake and a Jake do the same thing, they are both engine brakes. The Jake is more efficient at braking in my mind. Regardless of which type you have when you lift from the accelerator you start engine braking. I have said all i am going to now. Enjoy your travels which ever way you use the engine brake.

[LarryJB]

Originally Posted by Dav L

So, for the folks that leave the ebrake on all the time...what's the normal driving?

Cruise down i80...car in front is slowing down. Lift accelerator...eBrake engages. Tap the accel to coast. Car speeds back up, push the accel again?

That seems more busy more of the time then just lift the accel and coast. It's On or Brake. No On / Coast / Brake option.

First, I want to say that I do not encounter your scenario very often because most times on the interstate I set the cruise on about 62 and drive in the right lane. I can drive there for literally hours without once taking it off cruise. On the rare occasion when this does happen, I will tap on the brake to cancel cruise which will in turn engage the ebrake, slowing me down. When I am ready to resume my speed, I re-engage the cruise and I am back to 62mph again. All the while I may never even touch the accelerator. Easy peasy.

Like I have repeatedly said, you should drive the way that makes sense to you, and I should do the same. This discussion is good though, to point out alternative ways of doing things.

[Dav L]

Originally Posted by LarryJB

First, I want to say that I do not encounter your scenario very often because most time on the interstate I set the cruise on about 62 and drive in the right lane.

I too (like most) use the cruise a lot. But when I get to busier driving, I drive manually. Cities, road construction, narrow lanes, tight traffic, etc where I don't trust the cruise control single mindlessness. Or for hilly areas that the cruise doesn't have any anticipation for a steep climb ahead.

I also sometimes just like to Drive Keeps my head in the game.

I would say 20% is non Cruise. For those times, only 2% do I find I use engine braking at all (steep descents that aren't good for mechanical brake overheating). Heck, I don't use the foot brakes much when RVing due to the more laid back vacation mode of not having to beat every other driver to the next corner

The brake shoes are going to last till the RV is sold / scrapped.

The numbers are guesses but just to generalize. Going down the Rockies with car trailer in tow without having to touch the mechanical brakes is nice to know the brakes are ready for a sudden stop.

[Busskipper]

Originally Posted by Shutterbug57

I am new to large diesels. My new to me rig has an exhaust brake with an in/off switch. I understand basically what the exhaust brake does. My question is when should I turn it on or off? I have seen some folks that basically leave it on and others that use it only for going down big hills. Is there a downside to just leaving it on and using it to slow down at lights?

Simple, turn it on before you hit the brake pedal.

JMHO,

[anotherone]

and in the forum of incredible misinformation that clears up all the questions. 5 pages of every totally factual answer known to mankind.

[BobGed]

Originally Posted by LarryJB

First, I want to say that I do not encounter your scenario very often because most times on the interstate I set the cruise on about 62 and drive in the right lane. I can drive there for literally hours without once taking it off cruise. On the rare occasion when this does happen, I will tap on the brake to cancel cruise which will in turn engage the ebrake, slowing me down. When I am ready to resume my speed, I re-engage the cruise and I am back to 62mph again. All the while I may never even touch the accelerator. Easy peasy.

Like I have repeatedly said, you should drive the way that makes sense to you, and I should do the same. This discussion is good though, to point out alternative ways of doing things.

Certainly nothing wrong with the way you're engaging your EB when your cruise control is active, but in the vein off alternative ways of doing things, pressing your cruise control Cancel button will also activate your EB.

[Poppy01]

Wrong! They accomplish the same thing...using the engine back pressure to slow the vehicle. That is where similarity ends. Jake brake disables a number of exhaust valves depending on the level you choose.

An exhaust brake used a butterfly valve, just past the turbo. It does not have a hi/low setting.

The Jake brake does create additional heat to build up in the engine because the hot air from compression is not exhausted, which is the premise presented in the article posted.

The exhaust brake can produce additional heat in the exhaust system, but lower increase in the engine.

Both have pluses and minuses. Jake brakes are more efficient at slowing a vehicle, but are more complicated, therefore more expensive. Exhaust brakes are less complicated and less expensive, but less effective with heavy loads and put additional strain on the exhaust system.

Bottom line...they are not the same!

Originally Posted by NevadaNick

Exhaust brake and a Jake do the same thing, they are both engine brakes. The Jake is more efficient at braking in my mind. Regardless of which type you have when you lift from the accelerator you start engine braking. I have said all i am going to now. Enjoy your travels which ever way you use the engine brake.

[NevadaNick]

Read what i said, I did not say they were the same, i said they do the same thing, they use the engine to slow you down. By the way not all exhaust brakes are a butterfly valve in the exhaust, some use the variable vanes in the turbo to restrict exhaust. All i tried to do when i first posted is add some info to the equation, not start an argument about using it. I do it my way and you can do it your way, simple as that.

[twinboat]

Jacobson makes both " Engine " and " Exhaust " brakes.

Saying you have a " Jake " brake doesn't ID what kind you have.