Engine Brakes On 2016 Peterbilt 579

So I trained on a 2010 Freightliner for almost 2 months. The engine brakes were on the right side of the steering wheel and were fairly self explanatory. You pulled the handle down up to 3 different settings and the brakes engaged. Upon upgrading I was fortunate enough to be assigned a brand spanking new 2016 peterbilt 579 . The seats still had plastic and I got too see the 5th wheel greased for the first time! I am ecstatic about the truck, I love it to death even though I miss my 10 speed even though my left leg doesn't but I am very confused about my engine brakes. I have 2 buttons to the left of my steering wheel. One is to turn the brakes on and the other hasthe 3 speed settings. But they don't engage immediately upon pressing them like the freightliner. It seems they come on after a few seconds of applying my brakes and then disengage after releasing. I have searched through my manual to no avail. Anyone familiar with this and know the proper procedure to use them? I can only keep them going if I keep my foot on the pedal but I don't know if I will burn out my brakes keeping it the pedal held down going down a steep grade. I find myself snub braking with engine brakes lol

You must have them set at the lowest setting,or using them in high gear. They shoul come on automatically as soon as you remove yourself from the accelator pedal. As you lower your gears,you should get more engine braking.

Unfortunately I drive an automatic now. they do not come on when I release. that's how my freightliner worked

Our new International and some of the Freightshakers do the same thing. It's set that way from the factory but can be adjusted by the dealership to engage when you lift off the throttle. There's a few people who have complained where I work as to why in the world would you want to have to ride the brakes to use the Jake.

Our new International and some of the Freightshakers do the same thing. It's set that way from the factory but can be adjusted by the dealership to engage when you lift off the throttle. There's a few people who have complained where I work as to why in the world would you want to have to ride the brakes to use the Jake.

I hate it

Which engine do you have? My Kenworth has the paccar motor,if you have the cummings isx,it may run differently,my truck is also an auto.

If you have the cruise control on, they won't engage until you step on the brake pedal. If you turn the cruise off, they should come on as soon as you let off the throttle. My 579 ('14) is a 10 speed, that might make a difference.

Not that I know anything about these kind of trucks yet but an educated guess of mine would be maybe to help you getting better braking power by combining the engine brake AND the umm... brake pads (sorry I don't know what you would call that set of brakes... wheel brakes maybe?). 2x the brake power.

I could be wrong but that would be my guess.

Not that I know anything about these kind of trucks yet but an educated guess of mine would be maybe to help you getting better braking power by combining the engine brake AND the umm... brake pads (sorry I don't know what you would call that set of brakes... wheel brakes maybe?). 2x the brake power.

I could be wrong but that would be my guess.

Nothing wrong with chiming in Phox. The problem with having to apply the brakes to engage the engine brake is that while yes, it will give you the combination of both working together, the purpose of the engine brake is to allow the truck to slow down or control that speed using gearing and engine power. When going down a mountain for instance, correct gear choice and the engine brake make it possible to navigate down without hardly using the service brakes possible. The advantage is that your don't overheat the service brakes or even burn them up causing a fire or lack of control. By having to apply the service brake to use the engine brake in some ways, defeats the purpose of trying to spare the service brakes.

If you have the cruise control on, they won't engage until you step on the brake pedal. If you turn the cruise off, they should come on as soon as you let off the throttle. My 579 ('14) is a 10 speed, that might make a difference.

This sounds like it must be the problem, eh? I'm curious because I haven't run across this type of situation before. But there's this:

It seems they come on after a few seconds of applying my brakes and then disengage after releasing.

So even if you apply the brakes and the Jake comes on, when you release the brakes again it cuts out? Because hitting the brakes obviously disengages the cruise control. So the Jakes should be on if the switch is on and the cruise control is disengaged.

You certainly shouldn't have to hold the brake pedal to get the Jakes to work. That's no good. Let us know what you figure out.