Using a Johnson Bar Brake with Jake Brake on hills

You do realize that hand valve only applies trl brakes. Also if not careful you will smoke trl brakes and or catch them on fire. I use it all the time on my trk as i pull company trailers and wear out their brakes. Mine on my new kw stays where i put it. Also good for checking trl brakes for leaks on service side of brake chambers. Push in red trl supply valve then pull down handle and walk back to rear of trl and check brake lights and for air leaks. Also good for sliding stubborn tandems with out much wear on clutch. Release your slider pins and roll along in first gear at an idle push in clutch and pull down on handle tandems slide. Don't use this method for trying to slide only one or 2 holes.

 

The distribution of air to brakes on a semi trailer is designed such that about "55-60%" of the air applied (with foot pedal) will go to the trailer. if you go down the hill with the trailer brakes ONLY ("johnson brake") being utilized, they are going to get hot. And when you find yourself unable to keep the load in a controlled descent, you will then use the foot pedal, you're still going to be asking the trailer to do much of the work as by design but they will be too hot to provide much benefit and you will have to apply a LOT of air to make the tractor brakes try and play catch-up and do all the work because the trailer brakes are essentially useless at that point. Hope that I made a little bit of sense with reply.

 

Johnson brakes, I am told, are also good for straightening out when you start to jacknife in slick conditions. A little pressure to the trailer brakes slows it down while the tractor goes forward getting you straight- of course if it is pure ice it won't help much. No one ever wants to look in their mirror and see their trailer swinging around.

 

In my world it's called the "Trolly Brake". I was told to Never use it to help stop the truck except in an emergency, as in the truck brakes dont work. You will over work the trailer brakes using it the way you are. Over heated brakes wont stop a truck very well.

 

you get into a habit if using the handle brake only. then what ydou going to do when you brain fart in an emergency and reach for the handle instead of the foot.

now you've hit the car in front of you. you killed the kids. and spent the rest of your with 2 LOUSY hots and a cot behind bars.

the trailer brake is for emergencies ONLY. the pedal is for full time use. anyone that teaches you to use the trolley cuz they do it. is a fool themselves.

you've got 10 brakes to slow you down. 6 of them aren't there to be collecting dust while the other 4 burn out.

you don't use the emergency brake handle in your car. why would you use it on a 80,000 lb. rig?

i've also noticed my jakes get weak as the overhead wears down. they get strong again when the overhead is done. you work for a company that doesn't do routine maintanace. soon you won't have jakes to help you out with that trolley brake.

 

That makes a lot of sense. Although I am guilty of doing this as well. Never have I used that much air though. My gauge reads in increments of 15 psi and I have never hit the 15psi mark coming down a hill. I'd estimate the 8-10pai range on a down grade. My opinion on the matter you will usually have to use your brakes some on a down grade, if you've put 25psi back to them 5 or more times in a mile you're in to tall of gear. Jake on 3 if I'm in the right gear and the safe speed is 35 I can leave the trolley set at under that 15psi mark and never get above my safe speed. I have never smoked a set of brakes, never had a set get to terribly hot. Not to say that it won't happen someday but it hasn't happened yet. Sadly I don't believe in what that stupid book tells me which is hit your brakes to 5mph below safe speed release and repeat every 3 seconds I'd be out of air in a mile doing that crap. Brakes would probably be hotter at the bottom of the pass than doing it the way I do it now too. Just my .02 on the situation. I don't johnny bar my brakes to stop normally only time I use it is on a grade or testing trailer brakes. I do see you're point though with that much pressure going back there it'll fry them trailer brakes if he his a 3 or 4 mile grade.

 

Some figure their not their brakes, so what the h**l. Furthermore, when I smell burning asbestos, it makes me ill regardless who's it is. Just makes me nervous somebody is pushing their limits like that. And a lot of times it not so much the braking technique implemented but rather perhaps a single brake out of adjustment or defective and being applied way too hard in relation to the others.

 

It's amazing to me that this is even a discussion????? The guy who showed you how to do this is an idiot and....,.this is why companies apparently aren't putting trolly bars in company trucks anymore (so I've been told). I believe, but could be wrong, that this is even illegal? A Johnson bar is used to do a tug test or to check service brakes on a trailer. Could all this other stuff I.e. braking on a mountain be done?? Sure but that doesn't make it a good idea. It's this reason that fleets have to dummy proof company trucks anymore. Too many dummies behind the wheel.

 

how do you think trucks got down steep grades before every truck had jacob brakes or retarders in them. the real problem starts when a young driver machine guns off the top of a grade to fast. there is nothing wrong using the johnson bar to slow you down a little on a grade if used in moderation. have said this before dont put your life in danger for a $3.00 jake brake switch made in china. you see drivers do it all the time starting down sherman at 75 because they are lite. be careful out there