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Engine Brake (Jake Brake)

29K views 54 replies 12 participants last post by  gypsees 
#1 ·
I just bought a new 2017 Super Duty F-250 Platinum. While getting acquainted with all of the new gadgets and figuring out how everything works I ran across the engine brake On/Off button on the dash. After turning it on is there anything else I need to do? I don't seem to notice any difference after the engine brake is turned on. Should I notice the engine doing anything different? This is my first diesel truck.
 
#4 ·
As others have said, the engine brake really shines when loaded and in the upper RPMs, however, I've noticed that it does help a little when empty. When coming down a steep mountain I turned it on and off and could notice it working. I mostly noticed that the transmission shifts differently with it "on". I think its trying to keep the rpm's higher so that its more effective.
 
#5 ·
I pushed the on button on mine while driving and it would not activate because I needed to be going very slow. Is this something I should turn on and leave on? So far while I have been towing and going down hills the engine automatically slows itself. Would that be even more pronounced if I activate the Jake brake?
 
#6 ·
No, you don't need to have it on, or leave it on. Really, you don't have to use it at all, however, it is nice when towing, especially towing heavy.
 
#45 ·
You're partially correct. I have one but have no use for it and I don't have a heavy trailer. I only want to have a better understanding as to how all systems on my new truck work.
 
#8 ·
I'd like to use it I guess I just don't know how. I'm short so reaching up to touch the button isn't likely to happen. Surely they don't expect you to do that? I have never turned it on when I start up but thought I would do that next time I tow my horses. Seems like the message I got when I tried to turn it on before wanted me to be going so slow I did not see how it would help. That would make sense if you are supposed to already have it on. I'm just curious as to what the difference will be compared to my regular engine brake that works doing nothing but turning on the tow/haul button. I read the manual today about it and that didn't clear anything up either..lol.. I'm not sure who writes the manuals but they really are lacking in a lot of areas!
 
#9 ·
My wife is the owner of our 2017. She doesn't need the engine brake hauling groceries, and her horse trailer isn't heavy enough to really need it, but hey, its there and to be honest, she could care least if its on or not. She always says that brakes are cheap. When I'm driving I use it occasionally. Having driven trucks with actual Jacobs Brakes in the past, this turbo brake design doesn't excite me much, but its still better than nothing.
 
#10 ·
I haul in a 2 horse trailer sometimes when I am just riding locally. It is light compared to the other trailer I use when camping which is a 3 horse full living quarters with a slide. Typically we have two horses ( a little over 2000 pounds) and the third stall holds all our crap which is also not all that light. I don't remember how heavy the living quarters trailer is itself. I have electric brakes and they work fine but if I have a tool that would help, I'd like to use it. If all else fails, I will drive it into ford and make them show me how to use it and explain the whole thing..lol I also drive in the mountains a lot. I ride most often in the Great Smokey Mountains so I am keen to investigate any brake helper I can. I'm going to reserve how useful it is til after I understand how it works and try it out under a load. Nice to meet a fellow horse rider! :)
 
#11 ·
I don't quite understand the truck needing to slow down to engage the engine brake. I've engaged ours many times and speed was never an issue. Honestly, you can just experiment with it as you can't harm the truck by using it. By pushing the Engine Brake button twice you'll see the light come on with an "A" in it. That is the automatic setting. If memory serves me, I think it then applies the engine brake when the Tow Haul mode button is in. I may stand corrected by someone on that one though.

As far as the horses go, I grew up riding horses and rode up until I was hit by a car. I just haul the beasts around for my daughter now. She sure enjoys them.
 
#12 ·
I thought it was the reverse that the engine break slowed down the truck. I don't know but your explanation makes sense and I will try it next time I hook up. Did you get hit by a car while riding your horse??? I hate riding beside roads for that very reason. People have no clue that horses are animals and they never slow down. I think sometimes when people are under the influence and they see a pedestrian or an equestrian on the side of the road they veer towards what they are looking at. I will ride a road when I have to but I sure don't like it. Sorry you don't ride any more but happy your daughter does. It's a wonderful way to teach responsibility and to teach kids to care about something besides themselves..lol.. Besides that you have to have cooperation from a horse. You just can't push a pedal and go. Having a 1000 pound animal listen to you and building that relationship is really a special thing.
 
#13 ·
Wait, I guess I misunderstood your previous post when you said, "Seems like the message I got when I tried to turn it on before wanted me to be going so slow ". The engine brake does slow the truck down. It does so by using the turbocharger to slow the engine.
Regarding getting hurt, no, it wasn't on a horse. A fleeing criminal hit me with his car during an arrest one night. But you're right about riding on the highway, people don't pay much attention to horses. They spook way too easy. Especially when you get the guy who decides to blow his horn and wave at you when he's right next to you. That was always fun.
 
#14 ·
Totally agreed on the guy and horn..lol.. I've even had semis do that but always figured they didn't know any better. Thankfully I ride a most amazing horse who is not spook prone! Sorry you got hit by a criminal. I hope he went to jail for a long time! On the brake button.. that is what happened and so I assumed it was like 4wd in that you couldn't engage it except within certain speed parameters but then it seemed to me it would be fairly useless. I'm not sure it will even come on or do anything if it is on since I did get that message. Sorry I didn't understand til you clarified..lol.. I get it now. I'll report back what happens when I engage it next time. Thanks for the info too!
 
#15 ·
How An Engine Brake Works

A Jake Brake made by Jacobs Mfg. has been around for years in semi trucks. Uses engine compression to help slow the truck down.
 
#16 ·
I may stand corrected PawPaw, but we don't have a Jacob's Brake style engine brake on our trucks. Our trucks utilize the turbocharger rather than engine compression to reduce engine speed.
 
#19 ·
#20 ·
Found an article that says nothing about using the turbo...maybe I'm wrong but I always thought a turbo rammed more exhaust gases and air back into the engine only. Hell what does a truck driver have to know about the mechanics unless he's an owner operator that work's on his own equipment. :laugh2:
 
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#21 ·
Thanks for the link! I never knew how they worked before. But I did think that is what my truck did when I engage tow/haul. Is there a difference? My truck automatically downshifts to lower gears when going down a mountain for instance and I have tow/haul engaged. I guess that is not a jake brake and I erroneously thought it was since Jake brake doesn't seem to utilize transmission at all and engine compression.
 
#23 ·
I thought the exhaust brake on the 17's were just like the aftermarket units you can buy from Banks. They go in the exhaust, after the turbo and create enough back pressure to slow the engine. Since they got rid of the VGT turbo for '17 and went back to a fixed, dual vane setup; I don't see how they could control the turbo to create this back pressure.

A Jake Brake is a device that hydraulically holds the exhaust valves open on the compression stroke to create more work for the engine, thus reducing power/speed.

Banks Power | How An Exhaust Brake Works
 
#24 ·
According to Ford they do use the turbo to slow down the truck...simply amazing!! Tapping the brake twice in the tow haul mode works pretty good also.
 
#26 ·
It downshifts to raise the engine RPMs. This allows the engine brake to be more effective and it holds the truck back more. I hope this helps you understand it better.
 
#27 ·
What causes it to downshift? Is it possible I had the Jake Brake on and didn't know it? Or is something activated when I push tow/haul? I turned the brake on yesterday - but I won't be towing til later in the week. When I first pushed the button I got a notice on the dash panel that it was turned off. So I pushed it again and a message said it was on but I never saw any other indication it was on.

I drove the truck last night and my truck light position had been changed and now for some reason when I shut off the truck or put the key in the ignition the horn does a couple of short beeps. My husband swears he didn't change anything and I know the only thing I did was push that brake button..lol.. It's weird. I know that button didn't cause the other stuff but it is weird.

Since I didn't see any indication about the brake I wondered if it had a reset when you shut off the engine. And also I wondered if perhaps I had it on and didn't know it or if it comes on automatically whenever you hit Tow/Haul button because it definitely downshifts automatically when I am towing. I like that feature as it does save my brakes a lot. I'm going to read the manual again and also see if I can determine why my truck's horn beeps now when it didn't before..lol
 
#28 ·
Ok..I think I understand how it works better. I pushed the button twice (first time says it is off on the dashboard display). Then I start down my driveway which has a slight hill. I noticed a yellow indicator light was on so I knew I had activated this brake. As I was traveling down my drive way I tapped the brake and the jake brake kicked it. I felt something in my brake pedal as well and it slowed me down to like an ultra granny gear. So it is NOT the same thing my truck does when I use tow/haul and go down a steep slope but I can definitely see where this could be useful on some of the mountains around here. Thanks everyone for all the help and sorry for the stupid questions. I'm not completely mechanically illiterate but I am certainly not well versed either..lol..
 
#29 ·
The reason a engine brake was created was not only to save the brakes from wearing out prematurely but to not have them overheat. If you ever follow a large rig down a hill you will see him/her apply the brakes to slow a bit then release them to allow the shoes,drums to cool so another application can be made as the rpm's increase. If the driver were to come off the top of a long hill and apply the brakes as he crests the top the brakes would only hold for a short distance then become to hot for any friction or stopping power. With the addition of a engine brake the driver has more control over the speed at which he can travel down a hill. Since our trucks are made for heavy hauling it only stands to reason they should be equipped with an engine brake for those times that the road is hilly and the load is heavy.
Randy
 
#30 ·
Thanks Randy. I do think it is nice to have and I am certain I will end up using it. There was on mountain near Cherokee N.C. I was pulling my 3 horse loaded up it and my last truck got down to 35 mpg pulling it with the pedal to the floor. I worried it would even get to the top. The other side was just as steep going down and I think this would have come in handy though it did have the transmission shift tow/haul which helped a lot too. I'm excited to see how this truck will pull that mountain :) In fact that is when I decided to chuck the other truck after riding with my friend up same mountain in her Chevy and she didn't even have to shift gears. I was in shock. Hoping for same performance out of my new ford.
 
#33 ·
Nice looking trailer and horse! Looks like an Appaloosa to me. What is it with ladies and horses? All of my female cousins own horses around here.
 
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