Is there any practical use for a trolley break?

Okay... you're claiming that you're not critical of the Johnson bar, yet you're pretty much bashing any answer given to your question and putting forth an attitude that anyone who actually uses it for anything is some sort of moron. What exactly is your deal?

 

It worked for me..... don't ask for the story as it still gives me nightmares. But I will say that I needed a new seat afterword...

 

All that 'sperience gets tight in one's skull.

 

No, you really don't want to have to use it for that, but it's nice to know it's there if you do need it.

 

first, it is a Trolley handle...not a trolley brake...

other names are, "Johnson Bar" and "hand valve"..

the only real purpose for it is to check the operation of the trailer service brakes. in "ordinary driving" one should not use this trolley handle.....but of course, many do.

when i was with ComTrans (a division of NAVL-North American Van Lines), all of the tractors hand the trolley handle removed, to discourage the o/o's from using up the trailer brakes, all the while saving the tractor brakes...

 

Well don't I feel stupid, all this time I just thought it was the right turn signal.

 

...

 

Sliding trailer tandems? No! I like using the red knob, and doing it the old fashion way. I will use almost any excuse I can use to get out of the truck and get even the smallest bit of exercise.
__________________

As truck buyers get cheaper and look to cut that bottom line many trailers only have 2 anchor lock chambers ( parking brakes ) instead of 4. The Johnny bar airs all 4 wheels whereas the red knob will only set the 2 parking cans. (Unless you have 4)

This is very beneficial when you do as the Gemini driver I saw try to slide his tandems at the shipper....... after loading !!! Hmmmm. Being a tanker hand, I don't get that, but ok.....

Another lost tool in the truck is the blue air valve.... and true, the yellow red combo will allow you to do the same thing...... but I'm a trucker and I don't like it when you take things from me.

 

Yeah, hitting the throttle works real great when your going down a mountain pass full of snow and ice at 80K. Youll definitely get straightened out, right before you get all crumpled up.

Why exhaust trailer air again and again by pulling the red knob when you can momentarily apply with the johhny bar? Ive had more than one trailer that would just skid the tires across parking lot by pulling red knob. Used J Bar instead, and they slid no problem. I haven't pulled the red knob to slide tandems in years now...

Johnson Bar is just one more tool of many that we have available to us.

 

I certainly hope you are joking.

This "method" has been debunked for years but it still persists today???

First of all a locked wheel tends to want to lead the vehicle as it has no traction. The only way to regain traction to that particular wheel or set of wheels is to get the tires rolling again.

Now with that said the only way this method would actually work is in a drive tire spin out due to over acceleration. A slight tug on the trolley brake could pull the tractor back in line but then again letting off the throttle and stering into the skid will accomplish the same thing.

Try this method on black ice or an iced over bridge and you will find yourself sideways in a split second.

All the training videos since 1990 regarding this topic explain this concept and it does indeed work in the real world.

Of course some of the older drivers used to back off steer brakes so they wouldn't have to worry about loss of steering control in a hard braking situation. Another mistake but then again thats the way they were taught.

The best use of brakes on a truck is to have ALL the brakes properly adjusted and use them TOGETHER.

Using a trolley brake to descend a hill rather than using the foot brake to activate all the brakes is not only dangerous it shows how irresponsible and out of touch some of you are today.