To Jake break or Not

I have found most otr company truckers cant shift. If you are good, you can leave the jakes on and hit your shifts without jakes coming on and no harsh shifts on trans. When you let off the throttle peddle, you dont release to the point where jakes come on. Glide in to next gear.
Sounds like when you leave your jakes on, you release to the point where you scratching gears. Dont release peddle all the way. Or just not use the jakes and as you chose becuase you think you are wearing your jakes out. Even if you break a spring on one of your plungers after 500k of miles, replacing it and running the overhead only takes a couple hours. but to each their own

 

Sure small things add up. But there isn't going to be enough adding up from not using the Jake to be of a significant amount. Turning the Jake off would just mean id either be speeding down hill or using my brakes more. There is going to be no fuel savings, only choosing between brake wear or braking the speed limit.

 

Engine brakes are not brakes, they have and extra valve in the head, not a matter of wearing out anything, more of a matter of taking unwarranted chances of damaging your transmission or driveshaft. A Jakes so designed to assist you with controling or maintaining your speed they were never intended to replace your service brakes.

 

An extra valve in the head? Wtf are you talking about.

 

I know how the whole system operates because I break the components down in my shop and have them all laying piece by piece on my table to do repairs. WTH you talking about extra valve? I’m a local hauler owner operator mechanic that does my own motor work and can brake down the jakes and rebuild them and have them back on within 3 hours. I do motors trans, everything and also work on other companies trucks brought to me. But thanks for the attempt at schooling me. You by chance a company driver?

 

What about my Cat 3406? It doesn’t have an injection plunger activated by a cam lobe.

You are at idle fuel when the Jake Brake is in operation. Still burning fuel, but not much.

 

The head on a Jake Brake engine is the exact same head as a non Jake Brake engine, with the same number of valves. The Jake Brake unit sits on top of the head.

 

I leave my Jakes on most of the time on major roads where I don't need to shift often. At low speeds or in city driving, I normally leave them off.

 

Its done hydraulically. It utilizes a cam lobe from an adjacent cylinder, rather than the ones on that cylinder. Master piston transmits the motion from that lobe to the slave piston on the cylinder doing the braking at that particular time.

 

All I can do is shake my head at this thread. Soooooo much info is just completely WRONG!


Jakes do not cut off fuel. Your right foot does that.

Stage 1 operates 2 cylinders, stage 2 operates 4 cylinders and stage 3 operates all 6 cylinders.

There is no "extra valve" for the jakes. The jake works on a principal of hydraulics. When its actuated, engine oil pressure enters the jake assembly mounted on top of the head. This oil pressure pushes the master piston out against its return spring and allows it to contact the cam lobe. Cam lobe forces the master piston into the jake assembly and that motion is transmitted thru the oil to the slave piston. Slave piston pushes the exhaust valve(s) open. See what happens is the air compressing during the compression cycle is essentially working against the engine (absorbing energy). Now rather than letting that air force the piston back down after it passes TDC, the exhaust valves open and vent that compressed air. That's where the stopping power comes from.