The Jake brake

I was heading into Dubuque for a delivery one morning, cold, icy, on a downhill and my trailer started coming around like it wanted to pass me! Well, I was going as slow as I wanted to, and hit the trolley bar lightly, straightened that trailer right back in line. Like throwing out a sea anchor sometimes.
Not all Jakes are created equal, true that, but I use mine all the time. I use my cruise, too, on highway runs. Just a deviant, rule breaking, refuse to obey driver, I guess. I go by touch and feel, driven my rig about 400K, and we're a team now. Depending on conditions, on how it feels, that's how I do it.

Last. All this stuff depends on a lot of variable information. If you're heavy or light, how your axle weights line up, if your load is way up top or down on the deck (batteries!) all that has to be considered before making the choices necessary for road conditions. There's no silver bullet, no one size fits all for deciding on how to slow down. I laugh at the schools: "go down a hill one or two gears lower than the gear you came up in." Right. Like hills are all symetrical. It is to laugh. The towns that have signs posted: "No engine brake, ordnance xxx?" My Jake is muffled, it's quiet, but how can we go without our engine brake and be safe at the same time? Not going to happen. More rules to break!

 

Go on a Harley forum and try to debate that, they will ban you in a heartbeat! LoL

 

Oh he got a ticket alright. He was also on a weight restricted road and his trailer lights were out.

 

Talk about a triple crown winner!

 

I keep my Volvo in automatic most of the time so it comes on with the cruise control and also whenever I use the brakes.

 

That's what my kids call it! The younger ones don't yet know its real name.

 

I think it's better to break some rule than to break your ### because you're heavy coming down a 9% grade.

 

Loud pipes sound good unless you are in the truck and the AC goes out in the middle of the summer. You are driving 7 miles on the interstate up and over a hill pulling a belly dump train and jakeing for at least a mile coming down the hill to your exit. Oh and you do this for 2 days because the job needs to get done.... After the second day, or maybe sooner, you will make your boss give you another truck. After two days of listening to that jake and since this truck has straight pipes the exhaust of pulling that hill your head will be pounding.

Needless to say, the parts were ordered to fix the AC in that truck and I was put into another truck.

 

if your in a Cascadia with the dt12 be very careful in the winter. dd15 set on low is stronger than a lot of others on high setting.

 

There are three ways the Jake turns itself off if you don't actually turn it off with the switch: if you apply even a little throttle, if you engage the clutch even a little, or if the rpm's drop below 800. The last one is important for new drivers to understand the dynamics of using a Jake.

The holding power of the Jake basically follows the horsepower curve, you get maximum Jake from 1500 to 2000 rpm. You get progressively less holding power as you decrease rpm's. The reason the Jake is designed to cancel at 800 rpm's is to prevent stalling the engine.

Use this to your advantage. For example, if I'm approaching a stale green light in low rpm's I downshift so rpm's are 1400 to 1600, keep my foot on the throttle and turn the Jake on in high setting. That way if the light turns yellow I have close to maximum Jake the moment I get off the throttle and start using light or moderate brakes. If I were to stay in low rpm's the Jake won't help much at all.

On the other hand, in slick conditions I would rather engage the Jake in low rpm's, to make the transition to braking easier and prevent any chance of starting a slide. I might engage at low Jake setting in low rpm's, then increase to higher settings and monitor whether there is any slipping. The moment I feel slipping I SLIGHTLY get on the throttle, disengage Jake and then lightly get on the brakes to bring speed and rpm's down and start over.