Engine Brake While Towing
Actually, now that I think about it, mine did work down to idle because it was a manual. Auto's cut off at 1000rpm
Actually, now that I think about it, mine did work down to idle because it was a manual. Auto's cut off at 1000rpm
porthole- I had not thought to use the second 7-way connector port in the bed of my truck as a test point. – Thx
I think the secondary concern I had was lost in the debate; the potentially hazardous condition resulting from the engine brake engaging while towing a heavy load. I have not towed using my gooseneck setup yet, so I cannot speak to that configuration. Having the tongue weight place directly over the rear axle may have a different effect. In a typical “bumper” pull trailer the lateral moment is several feet to the rear of the rear axle. I generally tow with the recommended tongue weight of 10% to 15%. If the way I loaded the trailer and the tongue weight is not more than the 10%, I use sand bags to get the tongue weight I want. Yes, I do use a trailer tongue scale.
Anyone who’s spun out on black ice or just a slick road surface just by coming off the accelerator pedal knows that that sudden change of motion and loading can be an eye opener. So let’s consider this scenario, towing a 10k pound trailer, downhill grade, on a curve. The truck’s pull is forcing the trailer stay on the same track, but trailer is going to want to keep going straight (path of least resistance). Manually applying the truck brakes engages the trailer brakes stopping the trailer from “pushing” the truck. – (I was taught that the trailer should create a slight dragging effect on the towing vehicle). Throw in a slick road surface- you still have good braking force from both the truck and trailer. Now let’s add in the engine brake. No longer do you have the trailer braking systems help. Only the truck is trying to dissipate the forward movement and the trailer is pushing against the truck. This creates the potential of the trailer pushing the truck’s rear to the outside of the curve and a spin out. Yes, all the stars and planets need to be in alignment for this perfect storm and this hazardous condition. Myself, being new to engine braking and I am sure there are others in our FTE community who are also new to it, this is something to be aware of before you are in this situation. Obviously a long straight downhill grade would not be an issue. Curvy mountain downhill grades and the use of the engine brake should be considered very carefully.
I don’t use engine or exhaust braking if traction is even questionable. I want the ABS and related systems to be able to do their job.
porthole- I had not thought to use the second 7-way connector port in the bed of my truck as a test point. – Thx
I think the secondary concern I had was lost in the debate; the potentially hazardous condition resulting from the engine brake engaging while towing a heavy load. I have not towed using my gooseneck setup yet, so I cannot speak to that configuration. Having the tongue weight place directly over the rear axle may have a different effect. In a typical “bumper” pull trailer the lateral moment is several feet to the rear of the rear axle. I generally tow with the recommended tongue weight of 10% to 15%. If the way I loaded the trailer and the tongue weight is not more than the 10%, I use sand bags to get the tongue weight I want. Yes, I do use a trailer tongue scale.
Anyone who’s spun out on black ice or just a slick road surface just by coming off the accelerator pedal knows that that sudden change of motion and loading can be an eye opener. So let’s consider this scenario, towing a 10k pound trailer, downhill grade, on a curve. The truck’s pull is forcing the trailer stay on the same track, but trailer is going to want to keep going straight (path of least resistance). Manually applying the truck brakes engages the trailer brakes stopping the trailer from “pushing” the truck. – (I was taught that the trailer should create a slight dragging effect on the towing vehicle). Throw in a slick road surface- you still have good braking force from both the truck and trailer. Now let’s add in the engine brake. No longer do you have the trailer braking systems help. Only the truck is trying to dissipate the forward movement and the trailer is pushing against the truck. This creates the potential of the trailer pushing the truck’s rear to the outside of the curve and a spin out. Yes, all the stars and planets need to be in alignment for this perfect storm and this hazardous condition. Myself, being new to engine braking and I am sure there are others in our FTE community who are also new to it, this is something to be aware of before you are in this situation. Obviously a long straight downhill grade would not be an issue. Curvy mountain downhill grades and the use of the engine brake should be considered very carefully.
Of course, one could also read the owners manual:
Ford Trucks for Ford Truck Enthusiasts
So then that makes everything a whole different ball game. No one is born knowing exasctly what to do, but as the old cowboy said.
”Experience is what you get right after you need it the most”
But no, you definitely do not want your trailer pushing you around when traction is gone; but you also do not want the trailer brakes locking up and throwing the trailer into a skid either. Slow n easy is always best in those conditions.
Good luck and I truly hope you don’t learn what NOT to do.
Don't expect it to dramatically slow your vehicle. The system doesn't develop a huge braking force.
The exhaust brake system has 2 modes, manual and automatic. The manual mode applies the exhaust brake when pressure is released on the throttle. Throttle off, vanes close.
Automatic mode (press button twice) manipulates the exhaust brake and the transmission in an attempt to keep the truck at the speed where the brakes were last applied and released. In other words, coming down a grade with the exhaust brake in automatic mode, you step on the brakes and slow to 50 MPH. Your truck will try to maintain 50 MPH by closing the turbo vanes and downshifting.
Tow/Haul mode enhances the exhaust brake with more aggressive downshifts. More RPMs equal more braking force.
in AUTO it works with cruise to "maintain" selected road speed. if you have adaptive cruise, it will engage the service brakes if computer cannot control speed using engine brake/exhaust brake. Or so i was told by my service tech, and we read here that is most likely the case, but only if adaptive cruise detects your to close to the vehicle in front of you.
with normal cruise i have found that by watching the trailer menu to see if brakes are activated by the auto setting ...not so far in my case, but my load was light.
it would be an interesting test to see if in auto, with normal cruise if it does actuate trailer brakes to assist engine brake in doing its job.
in my motor home, the exhaust brake engages the brake lights on trailer and motor home, but does not engage trailer brakes unless i manually actuate them with the brake controller.
you would think the folks writing the books would be a bit more forthcoming in "operation" of system that could and can save brake wear and or make driving with heavy trailers and loads a bit easier and maybe safer
in my motorhome i use the exhaust brake religiously , it stays on everywhere but on the highway unless i am exiting. i f see a hard braking coming up from traffic i will select it with a simple reach of my left hand.
Actually, 388k now.
This is a more recent picture. I took this shot about a month ago. (I looked out my living room window one morning, and there she was - posing! Lol)
















