the unnecessary usage of j-brakes, why????

Simply put the problems not the engine brake. I use mine on a regular basis, even with the windows down I can not hear it, Hmmmm... Oh yeah, I have mufflers..... Maybe just maybe you need to learn to identify the problem before you start throwing rocks.... Probably 80 to 90 percent of the trucks use engine brakes and knowone knows because they have good working mufflers... As far as the other guys with stright pipes hang um high, they have a disregard for alll thoughs around them... and by the way we have enough problems here in the desert, please dont wish rabbit eaters on us too...

 

Just to add to this thread ;- the part above that states during this process deisel fuel stops momentarily beining injected into the engine chamber means that while the jake brake is being used you are saving diesel i.e. the more you use the jake brake the better your miles per gallon is. I know this to be true because I am mechanic and a Truck Trainer and teach fuel economy driving techiques. Having said all this drivers should consider the priorities i.e. number one is road safety
number two is consideration for others (after all
they buy the products we haul)
number three is doing the two above and still
saving money


By the way jake brakes and exhaust brakes have been around since the 1950`s

 

For the above poster, Clessie Cummins was the inventor of the first engine brake, then sold the patent rights to Jacobs.

 

Are you absolutely sure about that E-6?

As I understand the process of Jake Brakes is that when they're switched on, and the driver lifts their foot off the accelerator pedal, Jakes change the engine timing, causing the exhaust valves to remain CLOSED, so as to create resistance through compression without the introduction of a power stroke. Thereby, causing a resistance that assists the brakes, or causes the introduction of braking to be unnecessary, saving the bulk of the actual braking system from overheating the brake shoes/pads.

If the exhaust valves were allowed to remain OPEN, a piston would surely kiss that valve, and the engine would expire soon thereafter.

Or, have I been misinformed?

One way or the other, Jake Brakes are beneficial to SAFETY. Although SOME Big truck drivers misuse and even abuse the device. But this is a situation where to cause Big truck drivers to NOT use their Jake Brakes when the situation requires the added braking necessary to SAFELY hold speeds to a reasonable rate, is a step in the WRONG direction.
Why would ANYone demand that?
Comfort?
Who's comfort?

Safety?
Who's safety?

EVERYbody's

That's the bigger picture.

Big truck drivers seem to be darned if the do, and darned if they don't.
Give 'em a (Jake) Brake.
And hope they'll know when to use it and when not to (use it).

Perhaps a sign reading;
"Neighbors Asleep. Please consider us before engaging your Jake Brake."
Might help?

 

I think Mack is correct, AfterShock. It makes sense that if the compressed air is released from the piston chamber prior to the fuel injection, it would decrease the amount of power produced.

But I'm basing that on an auto mechanic's couse I took.... uhhh... almost 30 years ago. I'm old... and my brain may be confused. Maybe it IS best if we wait for Mack to respond.

 

Mack is correct, there is room for the valve. The reason is that having the exhaust valve open doesn't allow for compression, in this way the air is exhausted and in order for the pistons to move up and down it's using the forward motion of the vehicle. That energy of the vehicle moving is transferred to the engine thus slowing it, as it's being used to move the pistons up and down, instead of the explosion of air and fuel.

 

Drivers use their jakes for one reason..to let you know they are on there way into blue beacon.

 

STREAKIN' BEACON ?!

No thanx, amigo.

After spending half a day polishing aluminum, Beacon lived up to their reputation by using their fantastic "brightener" that makes a Big truck "sparkle" --- and polished aluminum look like a zebra.
The same stuff I told them I DIDN'T WANT.
That stuff.
I haven't been back to a Streakin' Beacon since.

I keep notes on where the best Big truck washes are located.

But I understand your point, Crozman.

I like the Big truck drivers who approach the fuel islands with the tach all wound up, ---- and hit the Jake.
Really cool when that fuel island is in Puckerbrush, Nevada, (former BURN'S BROS. --- remember BURNS RED Diesel Fuel?) and the ground all around is ice.
Hint --- think Slip-'N'-Slide ---------->
All around. <------------><><><>--<
On the ground.
Sideways.
Almost took the pumps out.
Diesel fuel on ice.
VERY slippery.
Color the Big truck driver who did that ---- stupid.
Or, worse yet, foolish.
In which case,........replace the word "Jake" with another word,............... "Jerk".
A "Jerk" brake.
Apply only when necessary.

 

As drivers we all like to use the jakes, pretty much anyway, some of the newer versions are really quiet and still very effective. As these systems grow they will be more available and probably law in some areas. If it is real bad you may want to look into a sound barrier of some sort. Being a driver myself, I find it more of an annoyance in the City where speeds are lower, yet Fire engines and dump trucks seem to think if they are there, they need to be on all the time, day, night whatever the weather. drive55cat

 

Here's what it says in the
Professional Driver Techniques and Owner's Manual that comes with a Jake Brake equipped Big truck, ...................

On page 3
Jake Brake Controls

The operation of the Jake Brake is fully automatic, once it is turned on. Depending on the type of engine you have, the controls for the Jake consist of either one switch or two, mounted on the dashboard.

Since the Jake depends on the free flow of oil for operation, be sure to let the engine oil warm up before switching it on. Normally, the Jake is then LEFT ON WHENEVER YOU ARE DRIVING.

Page 5

While shifting gears, the Jake is automatically deactivated when you depress the clutch pedal.
Under NO circumstances should the Jake Break be used for gear shifting. This could cause abnormal stresses and shock and may lead to engine damage.

Be sure to turn off the Jake Brake master switch when you shut the engine down.

If you have an automatic transmission, operation of the Jake Brake is basically the same. It is activated when you move your foot off the throttle, and deactivated when you re-apply pressure on the throttle. Also, there is a pressure-sensing switch that deactivates the Jake when the vehicle slows to about 10 MPH, to prevent stalling the engine.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I hope this information sheds some light on the PROPER operation of a Jake Brake.