Cooling your brakes

I certainly hope SOMEONE learned how to brake down a mountain pass in this thread :B
Next subject, the two foot driver :W

Lynnmor wrote:
To generate extreme heat for intermittent periods is a sure road to disaster.

You've got a real uphill battle on your hands here.

Lynnmor wrote:
The idea of repeatedly hitting the brakes hard and then coast back up to speed is nonsense. What you are doing is causing the brakes to go thru exaggerated heat/cool cycles.

This...... is what is nonsense! Driving truck up and over Donner and other passes, THIS will get you in trouble!

1. Shift DOWN at the top, at least one, if not TWO gears. You can always figure out you are in too low a gear, and shift UP, but, you cannot always shift DOWN, if you get in trouble!

2. You should NOT be using your brakes much. An occasional stab, hit them fairly hard, slow down at least 10 mph, then off the brake again, to let them cool.

3. If you find out that you speed right back up after slowing down, and need to repeat #2 soon, YOU ARE IN TOO HIGH A GEAR!

4. Then, if you are in too high a gear, use the brake aggressively to slow down, so that you can shift into a lower gear. GET GEARED DOWN!

You will get a feel for how much you need to gear down, but, in the beginning, make sure you are in a low enough gear! Please.

If others think you are going too slow, TOUGH.

Your engine should be doing AT LEAST 90% of the braking. You should only use your brakes Occasionally, and I do mean OCCASSIONALLY!

Coming down Donner, at 80,000#, I would be using the Jake brake, but essentially NEVER use the service brakes!

davisenvy wrote:

Lynnmor wrote:

2oldman wrote:

Lynnmor wrote:
The idea of repeatedly hitting the brakes hard and then coast back up to speed is nonsense. What you are doing is causing the brakes to go thru exaggerated heat/cool cycles.

No it isn't, and perhaps you are, but keeping your brakes cool is of utmost importance. Riding them is a sure road to disaster.

Brakes are a heat device. There is no way to use brakes and keep them cool. If you want to slow a vehicle with the brakes, then you will generate heat. The quantity of heat will be the same regardless how you play with the pedal. To generate extreme heat for intermittent periods is a sure road to disaster.

WRONG! Advice like this will end up really messing someone up. Whatever you do, DO NOT RIDE YOUR BRAKES. Stab the brakes as mentioned and go down the mountain same gear it took you to get up it, or even a gear lower if concerned. I can ride behind most out of towners and smell their brakes burning. The whole time their brake lights are brightly lit.

Actually that is what is taught now to new truckers ,5 psi on the application gauge and ride it down the heat is identical.
I was taught 'stab em and roll' but think about it same weight same speed same energy to dissipate and the heat is even .Of course air brakes have no fluid to boil so it may be only valid in that truck application.

Lynnmor wrote:

2oldman wrote:

Lynnmor wrote:
The idea of repeatedly hitting the brakes hard and then coast back up to speed is nonsense. What you are doing is causing the brakes to go thru exaggerated heat/cool cycles.

No it isn't, and perhaps you are, but keeping your brakes cool is of utmost importance. Riding them is a sure road to disaster.

Brakes are a heat device. There is no way to use brakes and keep them cool. If you want to slow a vehicle with the brakes, then you will generate heat. The quantity of heat will be the same regardless how you play with the pedal. To generate extreme heat for intermittent periods is a sure road to disaster.

WRONG! Advice like this will end up really messing someone up. Whatever you do, DO NOT RIDE YOUR BRAKES. Stab the brakes as mentioned and go down the mountain same gear it took you to get up it, or even a gear lower if concerned. I can ride behind most out of towners and smell their brakes burning. The whole time their brake lights are brightly lit.

carringb wrote:

Lynnmor wrote:

The quantity of heat will be the same regardless how you play with the pedal. To generate extreme heat for intermittent periods is a sure road to disaster.

The heat generated will be the same, however the "stab-and-coast" method does 3 things:

1) Heat energy is shed at a greater rate with greater temperature differential, so getting your brakes really hot and then not using them, dissipates more heat over the same amount of time then gently riding the brakes

2) By not riding the brakes, you allow for time when the friction material is not in direct contact withe rotor/drum surface, allowing better cooling

3) The "stab" part of the "stab-and-coast" method ensures all brakes receive even pressure which distributes heat more evenly. Under light braking, brakes may not be braking evenly, which can cause individual corners to overheat sooner.

Not riding brakes is a pretty fundamental part of driving heavy commercial trucks. It's taught in every CDL driving school, and spelled out in most CDL manuals.

From someone who lives here, made more trips over the Continental Divide than I can count with 110,000 lbs doubles of grain and holds a Class A CDL with doubles, triples, tankers, passengers and school bus this post is spot on.

Lynnmor wrote:

The quantity of heat will be the same regardless how you play with the pedal. To generate extreme heat for intermittent periods is a sure road to disaster.

The heat generated will be the same, however the "stab-and-coast" method does 3 things:

1) Heat energy is shed at a greater rate with greater temperature differential, so getting your brakes really hot and then not using them, dissipates more heat over the same amount of time then gently riding the brakes

2) By not riding the brakes, you allow for time when the friction material is not in direct contact withe rotor/drum surface, allowing better cooling

3) The "stab" part of the "stab-and-coast" method ensures all brakes receive even pressure which distributes heat more evenly. Under light braking, brakes may not be braking evenly, which can cause individual corners to overheat sooner.

Not riding brakes is a pretty fundamental part of driving heavy commercial trucks. It's taught in every CDL driving school, and spelled out in most CDL manuals.

2oldman wrote:

Lynnmor wrote:
The idea of repeatedly hitting the brakes hard and then coast back up to speed is nonsense. What you are doing is causing the brakes to go thru exaggerated heat/cool cycles.

No it isn't, and perhaps you are, but keeping your brakes cool is of utmost importance. Riding them is a sure road to disaster.

Brakes are a heat device. There is no way to use brakes and keep them cool. If you want to slow a vehicle with the brakes, then you will generate heat. The quantity of heat will be the same regardless how you play with the pedal. To generate extreme heat for intermittent periods is a sure road to disaster.

Lynnmor wrote:
The idea of repeatedly hitting the brakes hard and then coast back up to speed is nonsense. What you are doing is causing the brakes to go thru exaggerated heat/cool cycles.

No it isn't, and perhaps you are, but keeping your brakes cool is of utmost importance. Riding them is a sure road to disaster.

Hello.

When you check your brakes, look for heat checking of roater faces. Mine did check so I change them out for cross drilled / groved. Much faster heat transfer.