PDA

View Full Version : How I use my exhaust brake


roadglide
10-27-2016, 07:08 PM
I use it in city driving and keep plenty of distance. this is how it works tap the brake and let the engine do the work. I,m wondering if that is a good idea but it works excellent for slowing the rig down better then using the brakes. the mountain in Oregon using the exhaust will slow the rig down where I need to accelerate , using it is more stable and consistence stopping power.

chuckster57
10-27-2016, 07:58 PM
If it works for you, then keep on!! I don't have one, and can't put an aftermarket one on since I have hydraulic lifters. Your not causing any harm to the engine that I'm aware of.

bsmith0404
10-27-2016, 08:00 PM
It doesn't hurt anything to use your exhaust brake around town. The one advantage of using it is that it exercises the variable turbo vanes.

chuckster57
10-27-2016, 08:18 PM
it is that it exercises the variable turbo vanes.

When did the Duramax start using variable vane turbos?

xcntrk
10-28-2016, 07:43 AM
I absolutely love my exhaust brake. I turn it on whenever I hook up along with the tow-haul button. Turn it on and leave it on, city and highway. You hit a down-grade on the highway, even with cruise on, and it just works wonders rev'ing up the turbo to provide the exhaust back pressure. Works great in combination with the Tow/Haul to drop the transmission down a gear or two, which revs up the RPM's giving enough "breath" to the turbo to work. It's interesting to watch the boost gauge ramp up as the exhaust brake kicks in.

Desert185
10-28-2016, 04:56 PM
I absolutely love my exhaust brake. I turn it on whenever I hook up along with the tow-haul button. Turn it on and leave it on, city and highway. You hit a down-grade on the highway, even with cruise on, and it just works wonders rev'ing up the turbo to provide the exhaust back pressure. Works great in combination with the Tow/Haul to drop the transmission down a gear or two, which revs up the RPM's giving enough "breath" to the turbo to work. It's interesting to watch the boost gauge ramp up as the exhaust brake kicks in.

There was a discussion awhile back on a thread about not using the exhaust brake under slippery road conditions. What you describe makes sense considering what was said that exhaust brakes shouldn't be used during those conditions.

I have a PacBrake and a stick, so the use of the brake is perhaps not as aggressive as what you describe, and why I disagreed with what was said. Given what you said, I might have to agree with the cautions described in that previous thread. I also am glad for the combination I have.

gearhead
10-28-2016, 05:58 PM
I turn mine on just to hear it.
If I can remember, I'll turn it on at start-up in mornings to help warm the engine. These Houston area fall temps can get brutal. I had to put on long pants to go fishing this morning.

roadglide
10-28-2016, 06:16 PM
I agree about the aggressive engine braking and transmission down shifting with poor road condition. I turn the traction control and stabilizer on when towing has to help . I suppose with the stabilizer and traction control it will shift out of the aggressive stopping situation if it gos to pushing the TV.

bsmith0404
10-28-2016, 06:27 PM
When did the Duramax start using variable vane turbos?

They initially started with variable vanes on the LLY in 2004. Every now and then I'll put the vane position gauge up on my Edge CTS and watch how much they change and the associated boost that correlates with the different positions. It's pretty interesting to watch.

chuckster57
10-29-2016, 04:47 AM
Thanks for the info. I knew the 6.0 in Fords had it.

xcntrk
10-29-2016, 05:34 AM
There was a discussion awhile back on a thread about not using the exhaust brake under slippery road conditions. What you describe makes sense considering what was said that exhaust brakes shouldn't be used during those conditions.
Makes total sense. Same caution with riding the brakes on a grade in poor traction conditions. Only with the brake you can let off, with the exhaust/engine brake it's not so easy to get turned off and come down off the pressure at a rapid pace should things get squirrely..

bartbill
10-29-2016, 08:39 AM
Makes total sense. Same caution with riding the brakes on a grade in poor traction conditions. Only with the brake you can let off, with the exhaust/engine brake it's not so easy to get turned off and come down off the pressure at a rapid pace should things get squirrely..

Slightly different; but related question. Got a 2015 Ram 2500 Diesel. Going down a pass (say Monarch Pass in Colorado) with the engine brake on. Sometimes I want to get out of the engine brake but it seems the only to do this is to rapidly increase the rpms - by a lot - then kick it out of tow/haul. Aside from the obvious question of "why would you want to do that", is there another way to do it?

Desert185
10-29-2016, 03:01 PM
My exhaust brake is a butterfly on the aft side of the turbo. Just hit the switch to off...nothing else required, and I have a stick, so I'm my own tow/haul mode. Its pretty gentle when it kicks in, yet effective when its actuated. No fear of losing control on slick surfaces. Perhaps, progress can at times be regressive...or maybe I'm just getting old. :)

CaptnJohn
10-29-2016, 03:33 PM
Hit the button today ~~ not pulling the 5er but running the back roads of the TN mountains. Twists & turns / up & down.... made the drive more pleasurable.

xcntrk
10-30-2016, 05:52 AM
Slightly different; but related question. Got a 2015 Ram 2500 Diesel. Going down a pass (say Monarch Pass in Colorado) with the engine brake on. Sometimes I want to get out of the engine brake but it seems the only to do this is to rapidly increase the rpms - by a lot - then kick it out of tow/haul. Aside from the obvious question of "why would you want to do that", is there another way to do it?
Keep in mind Tow/Haul and the Exhaust Brake are 2 different systems. If you turn-off the Exhaust Brake, the transmission is going to drop a gear every time you're on a downgrade regardless - when Tow/Haul is enabled.

But that said, I have experienced what you're describing. I turn my exhaust brake on and leave it on. If you're cruising along on a downgrade and don't want the exhaust brake to kick-on, say for run-up to an incline, I'll simply gently roll into the throttle. I'm not versed on how all the turbo vein stuff works, but have observed when you apply throttle this seems to reverse the engine brake function. Easy way to keep it from engaging when not wanted - short of turning the system off.

roadglide
10-30-2016, 08:24 AM
It must be the Allison transmission and duramax, going down steep winding roads I ease into acceleration the transmission shifts up. I use traction control and stabilizer wile towing. The question is wile using the traction and stabilizer will that soften the engine exhaust brake in poor road conditions ?

bsmith0404
10-30-2016, 10:29 AM
It must be the Allison transmission and duramax, going down steep winding roads I ease into acceleration the transmission shifts up. I use traction control and stabilizer wile towing. The question is wile using the traction and stabilizer will that soften the engine exhaust brake in poor road conditions ?

I doubt it. Part of the effect with the exhaust brake is due to transmission downshift as well. For the exhaust brake to work properly it needs exhaust volume, in order to achieve the volume the transmission downshifts to create more RPMs. It's that combination of downshift and exhaust brake kicking in that creates the harder braking and adds concern in poor road conditions.

Desert185
10-30-2016, 11:14 AM
I doubt it. Part of the effect with the exhaust brake is due to transmission downshift as well. For the exhaust brake to work properly it needs exhaust volume, in order to achieve the volume the transmission downshifts to create more RPMs. It's that combination of downshift and exhaust brake kicking in that creates the harder braking and adds concern in poor road conditions.

Does this downshift only happen in tow/haul mode or will deselecting tow/haul prevent the downshift yet allow the exhaust brake to activate?

roadglide
10-30-2016, 12:31 PM
They computerized and work together . My friend has older dodge Cummings diesal he installed after market exhaust manual brake . The way I got he has to flip a switch nothing automatic . I understand with crus control on its challenging .

Desert185
10-30-2016, 12:46 PM
They computerized and work together . My friend has older dodge Cummings diesal he installed after market exhaust manual brake . The way I got he has to flip a switch nothing automatic . I understand with crus control on its challenging .

Yep. Not automatic other than letting off on the right pedal or turning the cruise control off with the exhaust brake "armed/on". From the sounds of the newer systems, what you describe as "automatic" is something I wouldn't want, as my system seems like a better, driveable option, particularly when experiencing a slippery roadway. Automatic and computer controlled as you described it would be challenging.

I find it odd that a manufacturer would design a system that would induce a loss of control under certain circumstances. Perhaps another case of too much college and not enough high school? Automatic and computer controlled are not necessarily always the best option, it would seem.

JRTJH
10-30-2016, 12:48 PM
I can't speak to how the GM or RAM systems work, but the Ford exhaust brake operates in conjunction with the cruise control and the transmission (either in tow/haul or regular) operation. When in normal operation with the exhaust brake activated, as the transmission downshifts, a "slight" braking will occur. in tow/haul a more aggressive downshift happens, and the exhaust brake action is also more aggressive, probably because of the increased engine RPM from the downshift. Tapping the brake pedal will cause the transmission to downshift, increasing exhaust braking action at the same time. Additional "brake pedal taps" will cause continued downshifting (one gear with each tap) until the vehicle is in 1st gear (higher vehicle speeds will delay the downshift until the transmission can downshift without "overspeeding" the engine). ie: The truck won't downshift into 1st gear at 70 MPH.

With the cruise control set, when descending a hill, the cruise will detect any speed increase and downshift the transmission to compensate and slow the vehicle, with the exhaust brake activated, there is a marked increase in braking action. I have not "heard" the exhaust brake, but do notice the engine sounds at higher RPM. There is no "jake brake noise" with the Ford system.

I can "visualize" how, on an icy or wet, slick road, tapping the brake pedal , even if it's just to deactivate the cruise control, and the "automatic downshift" that occurs causing the vehicle rear wheels to "lock up" causing loss of control. The exhaust brake can be deactivated by simply pushing the dash button, but once a slide has started, with the transmission in a lower gear causing deceleration, I don't know if pushing the button would do anything to help regain control of the slide.

With the ice and snow covered roads in northern Michigan, I'm not inclined to want to do much experimentation in traffic with the system. I'll probably do some "lonely back road" type trials this winter, but my current plans are to not even consider using tow/haul or exhaust brake systems on icy roadways.

Desert185
10-30-2016, 12:56 PM
I can't speak to how the GM or RAM systems work, but the Ford exhaust brake operates in conjunction with the cruise control and the transmission (either in tow/haul or regular) operation. When in normal operation with the exhaust brake activated, as the transmission downshifts, a "slight" braking will occur. in tow/haul a more aggressive downshift happens, and the exhaust brake action is also more aggressive, probably because of the increased engine RPM from the downshift. Tapping the brake pedal will cause the transmission to downshift, increasing exhaust braking action at the same time. Additional "brake pedal taps" will cause continued downshifting (one gear with each tap) until the vehicle is in 1st gear (higher vehicle speeds will delay the downshift until the transmission can downshift without "overspeeding" the engine). ie: The truck won't downshift into 1st gear at 70 MPH.

With the cruise control set, when descending a hill, the cruise will detect any speed increase and downshift the transmission to compensate and slow the vehicle, with the exhaust brake activated, there is a marked increase in braking action. I have not "heard" the exhaust brake, but do notice the engine sounds at higher RPM. There is no "jake brake noise" with the Ford system.

I can "visualize" how, on an icy or wet, slick road, tapping the brake pedal , even if it's just to deactivate the cruise control, and the "automatic downshift" that occurs causing the vehicle rear wheels to "lock up" causing loss of control. The exhaust brake can be deactivated by simply pushing the dash button, but once a slide has started, with the transmission in a lower gear causing deceleration, I don't know if pushing the button would do anything to help regain control of the slide.

With the ice and snow covered roads in northern Michigan, I'm not inclined to want to do much experimentation in traffic with the system. I'll probably do some "lonely back road" type trials this winter, but my current plans are to not even consider using tow/haul or exhaust brake systems on icy roadways.

I'm with you on that last sentence. Meanwhile, I'll continue to use what appears to be a more user friendly PacBrake and six-speed manual transmission combo, whether slick roads or not.

bsmith0404
10-30-2016, 01:10 PM
I have never had a wheel lock up from the combination of the downshift and exhaust brake. I believe the computer would also control that along with the ABS sensors, but the combination does work well to control 15k lbs while going down a mountain pass. The combination can feel aggressive, but to me it feels like a controlled aggressiveness. All three brands work on similar technology with just slight variations from what was described for the Ford.

With the exhaust brakes on pickups, you won't get a jake brake noise because it doesn't use that type of system. You can look up the difference between the two, but in basic terms, our trucks pump exhaust gasses back into the cylinders to create back pressure, a big truck jake brake system uses hydraulics to actually shut the valves and turn the motor into nothing more than an air pump.