EXHAUST BRAKE SWITCH (When to turn on)

[werni9]

Having trouble understanding "Exhaust" brake use. At 50 mph, I turned the switch on as I approached a town with slower speed. It slammed hard in the rear and started slowing. It took about 5 seconds from turning the switch on until it engaged. At the top of a downslope, what speed can I turn the switch on? Basically, how does this all work? Is tranny selection come first and then turn on "exhaust" brake? I almost wrecked and don't travel anywhere but flat lands. Would like to drive some hills knowing how?

[bbaker2001]

I checked the other posts, but did not get a good read why mine goes into coast at 30 mph. I would like it to keep lowing me down.

[jplante4]

Recently (last week) discussed thoroughly

Here

[Valkyriebush]

use mine on mountain downgrades and in town only when I think I need to slow quicker than normal. Otherwise off. I'm talking Allison trans compression brake?

[bbaker2001]

on my 2015 Ram 3500, I use it when coming down hill. never rally tried it in town. mine does not seem to stay on. when it gets to about 30, it kicks out. is this normal. makes it tough to use in town

[howdy35]

I do not run with the exhaust brake on. I use it as a helper when I want to stop or slow down. Ramping off the interstate or coming to a stop light. I prefer to use the exhaust brake instead of the service brakes as long as it is effective. Saves service brake pads.

In the mountains, I usually manually shift down to keep the RPMs up to keep the temp down. Many times when I get to the top, I leave her in the gear that got me to the top and go down the other side manually shifting up as the road permits.

I usually run with the cruise control on and the exhaust brake off. I find it irritating to have the exhaust brake on all the time since it will engage when I let off the accelerator. My theory is if I want to slow down or stop "hit the button" want to accelerate or travel "take it off".

Best of luck as you find what works for you.

[DSDP_Don]

It looks like you own a 2000 Winnebago Ultimate Advantage that comes with 300 HP Cat in a Freightliner chassis, with a Jacobs exhaust brake.

Your exhaust brake, when activated, basically blocks off the exhaust and causes the engine to build back pressure. At the same time, your Allison transmission will try to start downshifting, usually showing 2nd gear in your shift window. As the coach slows, the Allison will downshift until it reaches second gear. At some point, usually about 15 mph, your exhaust brake will disengage. (Some coaches are programmed to only downshift to 4th gear).

You can drive with the exhaust brake switch on and it WILL NOT engage as long as you are pushing, even lightly, on the throttle. Once you let off the throttle completely, the exhaust brake will engage.

Your exhaust brake performs better as your speed slows and you begin to downshift. You need to experiment with yours and see how well it works at different speeds. If you were to crest a hill at 60 mph and then start down the other side at that speed, your exhaust brake won't give you much help until you get your speed down to about 45 mph.

Some coaches, the cruise control won't engage when the exhaust brake switch is on. There are a lot of parameters that can be changed on newer coaches, so the exhaust brake will allow you coast when your foot is off the brake and some other changes. I don't think there are any adjustments on the older models.

Keep in mind in slippery conditions, you may want to limit your exhaust brake use. Applying it could cause you to spin out or lose traction. If you can, leave the switch on while driving, unless it cancels your cruise control. It's one less thing to worry about in a panic stop.

When in traffic or around town, you should leave the exhaust brake off and use your service brakes. Excessive use of the exhaust brake (lack of using the service brakes) can cause your brakes to burnish (glaze) and develop a squeal.

[slickest1]

You can run with it on or off, it is personal preference. It will not hurt anything or cause carbon buildup. When the switch is on and you take your foot off the throttle the e brake will engage. As you slow down the Allison will shift down once it is in the right rpm parameters. It will keep shifting down as you slow down. If you look at your shift pad it will probably show 2nd gear. It won't go directly to 2nd but will work it;s way down as you slow down.
On a long downhill that is fairly steep it is best to slow at the top of the hill and start down with the exhaust brake holding you back without having to use your brakes. This will save you from overheating your brakes and once they get really hot they will not hold you back. If you start down slow and it is too slow you can always go up a gear till you are comfortable. If you start down too fast you can overheat your brakes very quickly.

[MarkTwain]

kalynzoo wrote:
Your profile doesn't show what you're driving. Guess I am also a novice since I've only had the diesel for over a year. I was told not to bother turning the exhaust brake off. I always drive with it on, and I find that it decelerates the rig when I ease off the gas even before I press the brake. Makes my drive very comfortable. Out here we have lots of mountains and hills, and if I keep my speed around 45mph going down the mountains (truck speed posted at 30 to 35 mph) I seldom have to touch the brake peddle as the engine brake slows my speed nicely.
Happy Trails.

X1, run with my EB all the time since 2004, no problems yet:):)

[Kidoo]

I do not usualy have it on, i use it only when needed, like if I go down a hill or if I have to press the brake often like in town or in heavy traffic. On mine I can put it on at any speed but it does not engage if I travel like above 65 or 70. My exhaust brake is part of the turbo, VGT turbo type, it will engage only if I have the switch on and if I let go the pedal completly. If I only ease on the pedal it will not engage.

[Empty_Nest__Soo]

I don't leave mine on unless I'm in town, etc. In most other circumstances, I want to be able to coast with my foot off the accelerator when appropriate. When coasting down gentle hills, etc., the diesel uses zero fuel - I like that.

Wayne

[webslave]

I don't use mine all the time...have been told, right or wrong, that there can be carbon issues from running them all the time. I also, don't really want it to brake whenever I let off the throttle. When on roads that are gently rolling or flat, I want the vehicle to gain some speed in anticipation of the next uphill segment. A gain of 3 to 5 mph means I need less throttle going up. The ride is also smoother without the engine brake grabbing the coach every time I take my foot of the throttle.

I do use it in town, as it cuts brake usage when the speed limit starts dropping and between stops when in town. I also use it, to its primary purpose of going down steeper grades to let the engine slow the speed as opposed to riding the brakes.

That's the way I use mine, both in the coach and when I had a diesel pickup truck.

[kalynzoo]

Your profile doesn't show what you're driving. Guess I am also a novice since I've only had the diesel for over a year. I was told not to bother turning the exhaust brake off. I always drive with it on, and I find that it decelerates the rig when I ease off the gas even before I press the brake. Makes my drive very comfortable. Out here we have lots of mountains and hills, and if I keep my speed around 45mph going down the mountains (truck speed posted at 30 to 35 mph) I seldom have to touch the brake peddle as the engine brake slows my speed nicely.
Happy Trails.

[msturtz]

A make and model of coach would help.