Use Of The “Jake Brake”

I have heard different things when it comes to using the “Jake brake” when road conditions are slippery. I have heard to use it, and I have heard not to use it. Would some body be able to clarify this for me?

So as a general rule it's not advisable to use the engine brake in wet or slick conditions. The idea is because the Jake is only slowing the tractor down and if the trailer breaks traction you could be looking at a jackknife situation.

That said, I have used it in rainy weather before but usually in the lowest settings. I won't use it in snowy weather. I would recommend just getting used to handling the truck and using the engine brake in dry roads for a while. Before trying to use it in other conditions.

To add, its something that will take time to develop a feel for what happens when you use it. That comes over time. Not only does it only slow the tractor, it only applys breaking force to the drive axel(s) that are recieving power. So the trailer axles are free to spin, at a faster rate than the drive axels, causing a trailer jackknife or causing the trailer to effectively turn around the 5th wheel.

Weight makes a huge difference in how the truck reacts.

I routinely use the break in rain, but I use it with weight. If I'm hauling empty, I generally don't use it past level 1. Ive used it in snow and slippery conditions, but weight, speed and feel all go into that decision process. Ive also had the trailer start to come around on me, and I'm comfortable with how to correct it. That came over time from introducing its use in small amounts in an area where I could control it and get a feel for it.

Ive also played around a lot with applying light service breaks in conjunction with the jake to ensure relatively even breaking force to all tires, again though, I've done this where it was easy to recover at slow speeds.

Ive most western passes in Colorado, Utah, Wyoming, CA and such in snow with jakes, provided I was heavy and was slow on all of them while I was doing it. I don't recommend it as a new driver. Its risky.

The bottom line about "Jakes", being a part of the engine, is that they only affect the drive axle. So if the truck/ground traction is different on the drives from the other axles, the possibility for a jackknife jumps up.

Even service brakes, which affect all three axle sets the same could lead to a jackknife on slick surfaces.

In a slippery situation, just imagine how a jackknife would feel. That will help you decide whether to switch them on or not.