Do You Keep Your Cummins Exhaust Brake Set At Full?

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Goose55

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Some time ago, a member here whom I forgot his user name, strongly recommended keeping the exhaust brake set at full in order to help keep the turbo charger and actuator free of getting gunked up with soot. How many here also do the same?
 

crash68

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You don't need to use on full all the time, just as long as you use it.
 

06 Dodge

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I set my EB to Auto but then I'm not towing max weight, but if I was it would be on full
 

nlambert182

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It was probably me and yes, I run mine on full all the time. Always have, for the reason you mentioned above.

The actuator arm needs to move to prevent soot buildup and potentially causing the actuator to stick. Either auto or full is fine. You really don't have to run it all the time but an additional positive side effect of always turning it on is your brakes will last longer. :)
 

star_deceiver

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I always had mine on full. The actuator still **** the bed at 164000kms.

You think an $800 driveline fluid change is expensive? Wait until you see how much a dealer charges for a turbo actuator. They wanted $4k just for the part.
 

jejb

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I don't drive my truck much w/o a trailer behind it. But when I do, I don't use the EB much. Just bigger descents here in the Ozarks. When towing, I pretty much always have it on full.
 
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Choupique

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I'm not a fan of leaving the EB on when it isn't needed. It hurts fuel economy by limiting coasting. It drives the duty cycle on the actuator up. It increases wear on the transmission and driveline. I dont think vanes coking up is really a thing anymore. I believe all of the VGT diesels on the market fully cycle the actuator as part of the start sequence to validate the available travel and the position feedback.

Also, it seems that the people complaining on the internet of actuator failures always say "I even leave the exhaust brake on all the time and it still failed." It's probably the high cycle count driving that.
 

WY-Dave

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I can't remember the names but 1st press and 2nd press. I used to first press soon as I started up the truck. Then I realized that on the highway when I would let off the accelerator, for timing of other vehicles, I would be having to accelerate to get back to speed more than just letting it "idle" down. The one thing that might be a side effect of using it all the time is that my brakes lasted to just below 90k miles.

Now, if I am on the highway, I use the 2nd press for only when I hit the brake pedal. In town I put it on the 1st press. I did an experiment with the 30 mile trip going to work. 1 Day did 1 press and then the next day 2nd press, same direction/same speed/same weather conditions and seen barely 2 mpg difference. If it was an actual 2-300 mile trip I would think that I would get better results.

In either mode, sometimes the trans hits hard when decelerating and hits 30mph. I used alphaolb to show what was going on and either 3rd or 4th is skipped. IIRC 6-5-3-2-1. (tow mode or not) . On icy and even just a dirt road, the 30mph hit will actually lock up the wheels fir a split second.
 

nlambert182

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I haven't noticed a mpg difference between running it or not running it on full. I average 18.5 mpg in any of the 3 modes on my 24 mile commute to work. I can't imagine how it is putting more stress on the transmission or driveline. It's built to function exactly as it does. Once you are down to ~ 1500 rpms everything releases and it coasts, so it doesn't completely bring the truck to a stop. If you want to coast a bit longer, the lightest of pressure on the throttle will disengage the EB until you're ready for it and it will still coast.

If you pay attention when it's really cold out and you crank the truck to let it idle, the EB sets itself automatically (no light on the dash) because it brings the engine to operating temp faster. It turns itself off at 168 degrees. (Before anyone challenges this, you can ask Cummins and they will confirm).

I can't speak to what everyone is saying about failures while using it. I haven't seen a lot of complaints mention that but I'm sure there are some. At the end of the day I am mitigating risk as best I can and so far across 3 of these trucks I've been lucky enough not to experience the failure.
 

OLEJOE

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I don’t run mine all of the time but I do try to run it some every time it’s driven. If the vanes in the turbo are getting that much carbon on them, you are probably going to have DPF issues shortly. I think the active regens help clean the turbo when it injects the extra fuel pre turbo. Towing, I run it on full all of the time on the highway. I run it on auto in town towing or not but not all of the time.
 

nlambert182

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I don’t run mine all of the time but I do try to run it some every time it’s driven. If the vanes in the turbo are getting that much carbon on them, you are probably going to have DPF issues shortly. I think the active regens help clean the turbo when it injects the extra fuel pre turbo. Towing, I run it on full all of the time on the highway. I run it on auto in town towing or not but not all of the time.
There's no fuel injected pre-turbo.

It's injected into the cylinder on the exhaust stroke and ignited in the NOX canister, which is on the exhaust side of the turbo between it and the DPF. Nothing happens between engine and turbo.
 

chaosh1

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I use mine on auto all the time, Even when towing. The only time I drop it to full is towing steep downhill.
 

OLEJOE

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There's no fuel injected pre-turbo.

It's injected into the cylinder on the exhaust stroke and ignited in the NOX canister, which is on the exhaust side of the turbo between it and the DPF. Nothing happens between engine and turbo.
I believe the cylinder is before the turbo on the exhaust side and the fuel is catalyzed in the DOC before it gets to the DPF.
 
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