What is the Johnny bar for?

I.had to use it once to slide the tandems when the spring brakes wouldn't hold.

 

Couple serious uses I didn't see mentioned:

Spreading and closing a stretch RGN trailer.

Pull down and release several times after hooking to a trailer to activate slack adjusters.

 

We always called it a trolley brake....Some uses included:

• Checking 5th wheel locked.
• Sliding rear tandems
• Prevent jackknife in the winter
• Get rid of pesky tailgating 4 wheeler quickly, w/o slowing down.
• Save on your own tractor brakes

 

I pull it down at every light in addition to my service break.

 

Saved my bacon running downhill in the oilpatch, several times.

 

Is this something that has been phased out on newer equipment or is it an option to add or remove it from an order? Just curious as our fleet doesn't have this but the equipment in school did. I assumed it was just replaced with abs systems or something.

Thanks

 

Slow down and save the O/O brakes

 

Glad I'm not the only one guilty of using it that way haha

 

Never seen an air brake endorsement. Now I have seen air brake restrictions on licenses of people who road test in vehicles requiring a CDL but which don't have air brakes (e.g., F650 with a 20k gooseneck, etc.), but have yet to see an endorsement.

Ahh, you beat me to it. Stretch RGNs are a great way to separate those who don't understand how roads are formed (especially at intersections) from those who do. Ran across a pilot car driver, and he was showing off his setup.. F450... what interested me was that he had a Marlin crawler installed... wouldn't be odd to see for a trail rig, but for a highway vehicle? He explained to me he'd often use it when someone with a stretch RGN got hung up on a road crown, rather than sit and wait for a C wrecker to come out to do a winch out. Pretty sure he said he'd charge an additional fee for doing that, as well.

I ran dump trucks in NC for a guy who tied the Johnson bars into the truck service brakes... when you backed up to a paver, you'd just engage the PTO, set the hand throttle (it was a Mack RD), set the Johnson bar enough so the paver could push you without you rolling out from under the paver, then one hand for the steering wheel, and one for the hoist control. Worked like a charm. I never asked him the dynamics of it, but I'm assuming he just spliced it into the service chambers.

 

I wish I had a johnny brake. But I do check my service brakes from time to time. If soon after checking my service brakes I get passed by a four wheeler, that has hands at ten and two, a ghostly pale complexion, and a wide open jaw I know the service brakes are functional.