Question:
I have read several messages that are posted pertaining to braking. Certainly common sense seems to be a BIG factor. I understand the rule of thumb to descend at least one gear lower than you ascend. My question is how much will the lower gear really slow you down on a steep grade if you are heavy...no jake. How much will the engine/transmission take before something blows? I was taught in driving school to apply steady pressure on the service brake. If it's a long way to the bottom it seems at even a very slow speed the brakes would evently over-heat with steady pressure. And then, if you release them you're going to increase speed very rapidly causing the rpm's also to increase very rapidly. Did I make any sense??

Answer:
If you are loaded to 78000 or so you should gear down 5 gears lower than you came up. Better to slow than too fast you can always gear up, but don’t be in a hurry to do so it is easier to speed up than slow down on a down grade. You want to find a gear that will hold the RPM at 2000 that will not hurt your engine at all and your brakes should not over heat with steady pressure
Seek to know God and Jesus who was presented as the sacrifice of full payment for sin.
Do the VI maintain your following distance maintain your lane position observe the speed limit observe the things around you and keep good records
Safe driving to you.
Joe

Answer:
The key word is SLOW! You can go down a hill too slow many times, but only too fast once.
Start down the hill in the chosen gear, at the low speed for the gear you choose. If you have a jake and conditions permit, use it. If you can't use the jake or don't have one it is OK. Start going down at the low speed for the gear you choose, release the brake, and the speed will gradually increase. As it approaches the higher speed for the gear, apply the brakes and bring it back down to the lower speed.
You never want to have to do a shift on a steep downgrade because if you get hung up, the only way to get the truck under control is the brakes and you are coasting in neutral. This is very dangerous and you can easily smoke your brakes and wind up out of control hitting a ramp.
You also never want to let the truck get going too fast for the gear you are in. Very, very bad for the transmission and very, very dangerous.
You would be better off to get going downhill and realize you are going too slow than realize you are going too fast.
If you fall far below the posted speed limit, set on your flashers and stay in the right lane, both uphill and downhill. NEVER try to pass anyone going uphill or downhill unless they for some reason are standing completely still. If you do you will block traffic.
If you are going downhill and you realize that you have to swerve to avoid hitting a slow-moving vehicle, you are going too fast.
I don't necessarily agree with the one gear lower going downhill than uphill. I have pulled uphill at 25mph and gone downhill at 30-35mph. Look at the sign for the prescribed downhill speeds. Choose the proper speed for the weight of your vehicle and you will know which gear to use.

Answer:
Topic: steep downgrade baking--heavy load
I don't do much "baking" on the road, let alone on downgrades.
If you like, I can get my wife to help you. She does a lot of "baking".
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Answer:
First, whoever told you to use light steady pressure on the brakes is wrong, wrong, wrong. That is an old discredited method that can get you killed. Descending steep grades one gear lower than you climbed it is good but 2 gears lower maybe better especially if you do not have a lot of experience. When you are at the top of the hill BEFORE you start to descend, get in the proper gear and test your brakes.
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Use the Snub braking technique. If the truck speed limit is 25 mph, at 25 mph apply your brakes firmly enough to decrease your speed 5 mph in approximately 3 seconds. Release the brakes. When your speed reaches 25 mph repeat the snub braking technique. Snub braking insures that all the brakes are activated not just some. This is a question on the written portion of the CDL exam and is usually asked before or during the driving test.
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Balancing the load is a terrific idea before you start out. To find how many holes to slide the trailer tandems use this calculation.
Holes = (trailer tandem weight - drive tandem weight) / 500.
If the number is negative, shorten the trailer wheelbase. When the trailer load is balanced you will descend steep grades softer. You will not pick up speed as quickly. It rides a little better too. Plus you climb hills easier, get better fuel economy and reduce your oil consumption.

Answer:
Originally posted by xcis:
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Balancing the load is a terrific idea before you start out. To find how many holes to slide the trailer tandems use this calculation.
Holes = (trailer tandem weight - drive tandem weight) / 500.
If the number is negative, shorten the trailer wheelbase. When the trailer load is balanced you will descend steep grades softer. You will not pick up speed as quickly. It rides a little better too. Plus you climb hills easier, get better fuel economy and reduce your oil consumption.
First of all, not everyone has a foot between holes on the trailer. Secondly, the distance your load is from the back of the trailer is relative to how much weight is transfered, initially. In other words if you are light, the weight that shifts initially will be less when you are "shortening up". When the weight gets past the axle, then the weight being shifted increases more rapidly. I have found that if the trailers have 6" between holes, the weight is normally around 250-275 lbs. On trailers with 9" holes, the weight is normally around 375 lbs. The only thing I have ever adjusted that changes weight by 500 lbs is sliding my fifth wheel one notch.
As far as having your weight distributed evenly, the only factors I have EVER encountered are 1) the truck rides better, with no bucking when going over rough roads and 2) with your weight distributed evenly, your brakes work better, as you have the same amount of pressure on both drive and trailer axles.
As far as your observation on snub braking, some call it stab braking, I would fire you if you were driving my truck and I caught you doing it. In all my years of driving, every student I ever had tried this initially, and I let them. That is until the brakes started smoking. You hit those brakes hard, then release, then hit them hard again, repeatedly and all you do is superheat the air in between the drums and shoes and all of a sudden you can't get the shoes to make contact with the drums. Now this procedure may work on those short, steep hills back east, but try it on Parleys or Donner some time. --> --> -->
BUT, to all of you newbies, xcis is correct, the test says this is the acceptable method.
Now that I have confused all of you I have to go play in the snow and go run up and down some mountains(I80 in Wyoming) --> --> -->
[This message was edited by magicman on January 03, 2004 at 12:10.]

Answer:
If you slide the trailer tandems and the holes are 6 inches apart, each hole shifts approximately 250 pounds. The long way is to take the difference between the trailer tandem weight and the drive tandem weight and divide by 2. Then divide that by 250.
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The formula (trailer tandem weight - drive tandem weight) / 500 is a correct shortcut.
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If your holes are 9 inches apart and each hole slides 375 pounds then use (trailer tandem weight - drive tandem weight) / 750.
In general practice the difference is divided by twice the amount of weight each hole moves.
This ends the math class.
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Magicman has a valid point that the grades are steeper out west. If the weight is close to evenly distributed, you will not pick up speed as quickly when descending steep grades. Crossing Tennessee's 25 mph grades, in my last truck that was 7th gear, the load balanced and Jakes fully on; the rig for the most part just stayed at 25mph. Occassionally I used the snub braking technique if speed even started to exceeded 25mph. Evenly distributing the load is an aid. It is not a cure all. I did not mean to infer anything different.
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For any newbies or wannabe's ,since we are in the Newbies section of the message boards, get the CDL drivers manual from your state drivers testing site. Learn the difference between Stab braking and Snub braking techniques. Snub braking is the correct technique to use on steep downhill grades.
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Tests were done that show that light steady pressure on the brakes while descending steep grades is a recipe for smoking the brakes, brake fade and unfortunate results.
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Peace to all.

Answer:
Tests were done that show that light steady pressure on the brakes while descending steep grades is a recipe for smoking the brakes, brake fade and unfortunate results.
Smoking the brakes is caused by not being in the right gear to begin with and holding to much petal pressure. If you are in the correct gear and hold 10lbs petal pressure you will never smoke the brakes, at least that is my experience running Parleys and Donner for quite a few years.

Answer:
okay you too -- here's how it really is... -->
You got to do one or the other, decisively. If you snub, put your foot in it and get those steers brakes working too. Release and drift, Repeat.
With a jake, it should take at least twice as long to speed up as it did to braking. If you're applying the brakes more than 1/3 of the time, take the whole thing way down a notch -- SLOW DOWN -- and space out those snubs and let the brakes cool more. But give it a slow but deep braking and get all ten working.
The problem with steady light pressure is "proportional braking" technology favoring the trailer, drives and steers, in that order. If you're going to hold the service brakes going down hill, start with a heavier pressure to get all the brakes working, then carfully back off.
Otherwise, light application may only open the trailer brakes.
If you have a jake, there's no excuse for ever heating your brakes very much. We're talking about a couple/few minutes on most of these hills. California does it right. They slow the trucks down and keep them out of the left lanes, and they mean it. It cost truckers less than five minutes to do 35 for a few miles. At least....that's the cheapest, safest way to decend a hill. --> In fact, if let the jake do the whole thing, and save the brakes for unexpected conditions ahead.

Answer:
Shuffler has the normal reading problem, No Jake.
The question is, "My question is how much will the lower gear really slow you down on a steep grade if you are heavy...no jake" The answer is not very much at all. A heavy truck can blow right through that lower gear real fast. Gravity couldn't care less about the gear your in. While the proper gear does help it wont stop the truck. The key is your speed when your start the down hill. Start slow and keep it slow. Another key on the big ones is to stop and check your brakes. Don't assume their working fine because all has been well up to that point. Out of adjustment brakes do not work well and will cause some to heat very fast. I know some companies don't want you touching them. Because I am the one going down the mountain I go ahead and touch them.
I've done both with no jake. Light steady pressure and stab braking. I like stab braking much better. I'll stab the brakes for 3-4 seconds to reduce my speed about 5mph or more then release for 6-7 seconds and hit them again. My brakes have not everheated doing it that way. The key again is speed. Do not let the truck get above the speed you need to stay at. If it starts going to fast you have invited trouble. So keep it at or below that speed the whole way down.
I had a trainer teach me to use light steady pressure. That to was ok on Shorter hills. Again you can't let the speed gain. But I found on longer hills the pedal would become a bit soft. So I prefere the stab method. Stab Snub or what ever you want to call it. I just use enough pressure to slow it down where I want and release.
" Better to slow than too fast you can always gear up" I wish Joe wouldn't have said that. It's simple. Do not change gears while going down a hill for any reason. If you miss it and dont get it back your in for some real problems. Like what has been said above. Better to slow than to fast. So just stay where your at until you've hit bottom.
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Answer:
I currently have a truck with no jake brake and I can tell you most definately that at 80k I can take any hill with the proper gear and steady brake pressure without smoking the brakes. It take a while with many trucks blowing my doors off but it can be done.

Answer:
I agree with you Stuffs. That's good.
It's really the same for jake or non-jake trucks. Brake hard 1/3, drift 2/3, brake hard 1/3.....at least.
Jaked trucks do exactly the same thing, but they can do it a little faster, or use the jake exclusively -- but otherwise it the same stab, release...3-4 seconds to 6-7 seconds. I totally agree. This little tip-toe father braking stuff can be very dangerous - or light up your trailer tandems - if you don't do it right. 1/4 or 1/3 stab braking is much better, good post.

Answer:
zeroday,
That's because you're doing it slow and right and just the right balance.... craftsmanship, but some of these folks just tap their brake going way too fast and don't even think about it...
No matter what you do, the longer it takes you to get to the bottom, the less your brakes heat up.

Answer:
Thank You, I might be going 25mph but I will make it to the bottom of the hill with no smoking brakes.

Answer:
What would you do if, halfway down the hill, your brakes DID start smoking...??????
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