Braking in snow and ice

I'm going to have to read up on tractor-trailer brakes. I think my confusion is simply because I'm not very knowledgeable of big truck systems and controls. I was thinking that a driver could use tractor and trailer brakes (excluding the jakes) in increments, simultaneously, to control the speed reduction of the vehicle. By applying braking of the tractor and trailer at like pressures, I would think the driver would have optimum control of his/her rig.

So... that's where I get hung up here. And like I said, what I stated may not be possible... and not being a driver, I am revealing my absolute cluelessness.

 

don't use your johnson bar unless you want to see your trailer passing you (IMHO)

gear down gently... use the foot brake... they may be wet and take a second to dry out and function at 100% as intended.

if you do start to slide or break traction, push the clutch in quickly and it will straighten out for you. (generally)

watch the mirrors as you brake... the thing passing you might be your trailer...

yeah but how do you know when its icy or freezing rain???

well... sometimes its hard to tell... but generally you can see it on your mirrors or else roll window down and feel for ice on the back side of the mirror support bar. It will often start to freeze the bar before the road actually get slick.

 

If you have to stop, your are already slowing down because your foot is off the accelerator.

If you apply the brake, and lightly pull your "Johnson Bar", and keep an eye on your mirrors because your trailer will slide one way or the other when not properly adjusted, because you can release the hand valve to straighten up by keeping a little pressure to the drives and slow down pretty quickly this way.

Most modern brake systems today, like ABS apply pressure to the trailer first, and then release when they start to slide.

 

If you are using your gears to slow down and you start to slide, press in the clutch to disable the engine braking on your wheels. This gives you more control.

If it's really bad out, put the truck in neutral and use JUST your foot brakes and try to slow down that way. It's the safest way but you don't always have enough time before you slide out of control.

At least most trucks are rear wheel drive. I learned to drive in rear wheel drive cars and still find it easier to get out of a slide than a front wheel drive where you need to either get in neutral/depress the clutch or accelerate to save yourself in a skid. On a rear wheel drive, you "let go and steer" as in get your foot off the gas, don't brake and steer best you can. In a front wheel drive, this locks your front wheels and you're screwed.

Putting the truck in neutral means you completely control the braking of the wheels and can feel what's happening. Experience is the best teacher and, if you have a large empty parking lot somewhere, practice a bit in fresh snow if you can (going SLOWLY!!!) and see how the truck reacts to different things you do - slam on brakes, use the trailer hand brake, put it in neutral and use only the foot brake, etc.

 

ON solid ice, you basically have no control of the vehicle, even going at 5mph. Turn the steering wheel and the truck keeps going straight. Found that out the hard way, a long time ago. Hit the brakes and the truck just slides. In fact, the only thing that seemed to work to turn the truck was to take my foot off both the accelerator and the brakes and just slowly turn it. I was - well, wasn't very smart, put it that way - and kept pushing it. Took me hours to go a few miles. I didn't crash into anything, but I never attempted it again.

 

If you put your truck into neutral, you will have NO control of your rig, very bad idea. Might work for your car . If you miss a gear you are screwed. Slow steady pressure is the best method and using the gears.

 

So if you start to slide and put the truck in neutral, you're saying you cannot STEER it? Why not??????

If you're sliding by applying the brakes, you need to let go and get the braking OFF the wheels.

 

Always keep the truck in gear. You've got to remember that a diesel engine has alot more torque than a gasoline engine and in bad conditions you want to reduce that torque to the pavement. So I try to keep the truck in the highest gear possible that will still let me accelerate. Everyone is right to say slow down, I would take that and slow even more.

I used to haul LTL freight so stopping was no option. Unless of course the road was shut down. With the LTL I had to pull three pup trailers. I ran into alot of bad weather at night in northern Nevada. Sometimes but very rare we would drop the last box so I was running across I80 from Reno to Salt Lake when I ran into the worse of it. Sure we'd have bad places just south like at Eagle Pass going south out of Ely NV but you knew it wouldn't last.

I stayed off the brakes as much as I could. But I will have to stand up here and talk about the traiker brakes. I would use the hand valve or trolly valve or whatever you want to call it but only going down the grades. I would pull down on the valve just enough to engage the brakes, about 5 to 10lbs psi. This would keep the set straight. It's not enough to really slow you down but just enough to create a pull from the back forward. But after you get down don't use that hand valve anymore because you want the same situation when going up, a pull from the front. Other than that leave those trailer brakes alone.

NEVER use you engine brake. If the road is icy you WILL lose control.

The most important factor to remember is to slow down and stay in your comfort zone.

 

it applies even braking pressure to both tractor and trailer. The trolley bar or johnson bar is not necessary( and should not be used) to use when braking. It should be used to do the brake test on the trailer during your pre-trip and to tug the trailer when hooking up. I think in the old days, drivers DID use it for braking because the trucks didn't have a valve for applying even braking pressure with the foot brake. Something along those lines I believe. Now-a-days many trucks don't even have a trolley bar because it isn't necessary .

 

The term "Johnson Bar" dates back to the early 1800's where is was a lever on a steam engine (train) for reverse. FYI

As for what to do during snow/icy conditions;
1) Maintain a safe speed (take your time)
2) Increase your following distance
3) Watch further ahead
4) Easy on the braking, no sudden movements