Safe to use engine brake on slippery wet roads?

if you have any modern truck with any form or traction control and ABS, if the traction control cuts power under wheel slip, the engine brake will disengage the same way under wheel slip. just test it out somewhere you know there's zero grip, as soon as the computer senses wheel slip the engine brake automatically disengages, truck doesn't even have time to start going sideways.

problem with pressing your luck though is if you only have X amount of traction left and engine brake uses it up, even if wheel slip shuts it off immediately it still might trigger a slide, where the only way to fix the lateral movement is to accelerate again to straighten out. but if you're already tight on room or time...

if it's that slippery I'm gonna be crawling anyways. or parked. I'm from the south and the first few years of northern white winters was really fun in either a company rig or new lease equipment under warranty. I love being in the cold but not stuck in it, or dead duck freezing for no reason. nursing an aging rig through the arctic is NOT exciting anymore. I will never complain about being hot and sweaty ever again. being stuck in the heat is just annoying and make you go crazy, or put you to sleep, get stuck in the cold can turn into nightmare fuel real quick. heat won't actually kill you

 

Those brakes are bias as all hell. Go ahead and put that straw in your mouth and watch what they do. You’ll be slip sliding from Pennsyltucky all the way to the Georgia state line.

 

mine is connected to my traction control, if the wheels slip, its stop jaking.

 

I have my jake on all the time. Only exception is if black ice conditions exist.

 

That traction control can be a bad thing though. Last thing you really want when coming down a hill in the bush is for the jake to cut out because one set of duals is starting to drag a bit but not enough to stay locked. 100k+ lbs can push you out of control pretty quickly on a steep grade if the jake shuts off suddenly.

 

Its why understanding physics would of been good when we were still at school, when it comes to applying the brakes on a slippery surface, Prime mover (tractor) weights about 16 000 lb give or take a few lb, the trailer weighs about 64 000 lb who do you think is going to win that push and shove contest? So hitting the brakes to hard will only result in one outcome, option one try not to use the brakes, option two apply trailer brakes only very lightly if possible which will pull you back. Unfortunately, due to all our 4 wheeler driving days our natural response is to hit the brakes so one has to train ones mind to think differently when driving an 80 000 lb tractor- trailer on icy roads.

 

Actually, because the tractor carries much of the trailer weight on the 5th wheel, the tractor is the heavier part of the combination. So one is much better served to use all the brakes available.

Now if things get out of shape to where the tractor is starting to jackknife, one has to consider the mass of the trailer and load. But quite frankly, if one is weight-biased towards the drives, and because drive tires tend to have better traction than trailer tires, the far more likely outcome is for the trailer to step out a bit, which is a much more stable situation than the drives sliding.

In our ABS world, as in the pre-ABS days, a jackknife under braking is usually due to under performing trailer brakes. Although it seems nowadays as many are caused by drivers who don't understand the difference between neutral throttle and no throttle. On glare ice, just plain old non-Jake engine braking can lock the drives and cause a very rapid jackknife.

 

My new pickup has traction control. It will actually get you in trouble on slick roads if you try to “drive” the truck for the conditions. I don’t like it and will turn it off if roads are slick. A computer can’t “drive” the truck as good as a well trained driver when things start to go south.

 

The Jake brake is used to save the regular brakes and let you go downhill faster. In snow and ice your not wearing about try to save the brakes and get longer life out of them or going faster down hill.

Your goal is to get down the hill without an accident. Why would anyone not use all the brakes you have for the most traction possible. We don’t want to be relying on ABS or Traction Control to get us downhill every time. You can use light steady pressure on the brakes and ride them all the way to the bottom. You will be going slow and in control. ABS and traction control is good to have it can help save us, I was trained before that and you don’t really on it for every hill. It’s more of backup to help save you if from things going out of control

 

You consistently state this and you're not wrong that it won't overheat the brakes, but doing so uses up brake system capacity that one might wish they had if things go sideways. A braking system is a heat sink, and riding brakes all the way to the bottom at low application pressure might not overheat the brakes, but it will use up most of the system's heat capacity. A hard brake application while coming down a hill in your suggested manner is almost guaranteed to send the system into overheated status. The controlled low pressure descent has a balanced heat in/ heat out dynamic, but that does not mean the systems heat capacity hasn't been needlessly used up.

Why would one intentionally leave one's self in a situation with a reduced ability to stop?

I think of them more as early warning devices (at night mostly) or confirmation of visual indicators of reduced traction in the better visibility of daylight. One doesn't use them to keep the truck under control, but they'll let you know if conditions aren't quite what they appear to the eye.