During my OTR training, my trainer told me to turn off the Jake Brake switch when going uphill. He said that having the switch in the on position effected the horsepower of the engine.

I did as directed. But, it didn't make any sense to me.

Is this true?

 

I'm not a mechanic, but I don't see how with one exception. The Jake Brake is not functional when the clutch is pushed in. So when you down shift it won't make a difference, unless you have a splitter, as in 13 or 18 speeds. I forget to turn mine off until the first time I split and I always wonder what's up with the engine.

 

Ahhhh, I guess I should add, I drive an auto-shift.

 

Nope, doesn't make any sense at all.

The only way a Jake brake is going to come on is to let off the fuel. Why would you let up off the fuel while going up a hill? The Jake brake is turned on and off by a electrical switch so there is nothing mechanical in the switch (being a Jake brake is mechanical), thus making no difference if the switch is on or off when the Jake brake is not activated.

I might be wrong? But I can't see how there would be a difference?

 

You were told a load of poo.

 

Only time I turn my Jake off is in backup traffic...or when I enter areas other Truckers are likely sleeping.

First time I heard of something like this...and now I guess I've finally heard it all. :lol: .....er...naw...plenty more BS where that came from. :roll:

Tell this Trainer to become a member of CAD. He could use our help. :P

 

Bull butter! Jake brakes work when you let off the throttle. As long as you have your foot into it, they wont come on. As soon as you let off of it, they come on. Your trainer is full of beans. He needs to be trained. :P

 

Your trainer if F.O.S. :roll:

 

I agree with everyone else. Having the jake switch on or off shouldn't matter. However, there can be different horsepower settings between the cruise control and the pedal. It depends on the truck and whoever programmed it. Some are 470 on the cruise and 430 on the pedal, or 430 on the cruise and 370 on the pedal, etc. It's power ratings depends on the the engine make and whoever in in control of the ECM parameters. Maybe this is what your trainer meant ? 8) 8)

 

just had the wife try it nothing changed still 43mph, and yes it's an auto-shift

a side note on our 05 & 06 freightliner with detroit power the jakes were set to come on when you hit the brake's, :shock: on both truck thats the way the ecm was set so we had to have then plug in the laptop to change it