Going down long steep "DOWNGRADE"

Number one, Your with a instructor, follow directions. As a student you can not judge what is too fast or too slow for the conditions so I would have to rely on the experienced driver with you.

You obviously lived thru it. And have a lot more training to endure, so stop second guessing the trainer and follow direction, this will increase your chances on surviving.

 

Kind of got to agree with this. You are learning.. BUT BUT BUT if you feel that you are performing in an unsafe manner that is on you not the trainer! I don't care if he tells you to put it in neutral going down the hill. It is your problem.. It is your CDL.

 

You can go down a million times to slow,but one time to fast.I believe thats what the saying is.Show me a truck driver that hasnt been in trouble going down a mountain pass,and ill show you one that will be.

 

On grades of 5 percent or more and over three miles long,with no jake.of course this would be loaded heavy,highest gear low range,5 to 10 lbs of constant pressure on brakes,you wont even get them hot.

 

You better not say that. You will get 100's of replies telling you how you are going to burn up your brakes, wreck the truck, and kill many people. At least that is what happened to me, especially from a one year wonder whose trainer told him that.

Of course, someone that don't know what 10 lbs, or light steady pressure means, probably would do that.

 

been training for years,been teaching that for years at 80,000 lbs,not once has any of my students smoked the brakes.parley cabbage tou name it.if done right you can get out at the bottom,touch the hub,and they wont even be hot.

 

Thats the key,the light steady pressure.If you let air get in there,well we all know what happens to fire when it gets oxygen.lol.Take your hands w/palms together,and rub them together as fast as you can.What happens?They get hot right?Now do the same thing real slow,could do that all day w/out them getting hot.That is the principal.

 

One of the fundamental laws of physics states that we can't create or destroy energy.When you have a truck at an elevated altitude this is called potential energy.When it starts descending this energy gets released as dynamic (moving energy). The more weight the more energy and the steeper the gradient the faster the release.As we cant destroy this energy it has to go somewhere.A Jake brake converts this to heat and sound energy predominantly. Foundation breaks convert this energy predominantly in to heat energy.This heat energy has to dissipate in to the surrounding atmosphere or the breaks will absorb to much heat and burn.This is the reason people say let air get in there.This air can absorb some heat energy and carry it away. This is a major reason disk breaks are better at breaking.There is better air flow over the friction surface where the heat is generated , thus better and faster heat dissipation.

 

What happened to "kinetic" energy??

 

If one or two brakes are adjusted tighter than the others, they will get hot. That is the reason snubbing became the approved method and the Commercial Drivers Manual was change 5/16/93. Be sure to answer "snubbing" on your exam.