Caging your air brakes, to tow a bus that's not running.
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- čas přidán 24. 08. 2024
- I needed to cage the spring brakes on a Freightliner skoolie conversion bus, to prepare it for a tow. Caging is the process of using a special bolt to release the spring brakes on a bus or truck with air brakes, so that the parking brake is held off. This releases the parking brakes and lets you move the bus, if it's not running or won't build air pressure.
Keep in mind...if you do this, your bus has no brakes holding it in position...so, block/chock the wheels and be safe when you move it. Caging the brakes is only done to tow a bus - never try to drive a vehicle with the spring brakes caged. Don't get dead.
Here in the UK I have occasionally experienced some dead vehicles that even need the front brakes to be caged as well before being towed.
Well, that's certainly a new one on me!
As far as I know, in the US, school buses only have emergency/parking brakes in the back.
If like to add that you'll be turning that caging bolt a long time. I recommend a quality ratcheting box end wrench. Wrench on that thing until you can't turn it at all.
I think it's only 460 turns...not that long! :-) Seriously, though, you're right...it's a lot of turns. Turn until the spring's fully compressed and, often, there's a mark on the shaft too. But wrenching until you can no longer turn it is the best.
I always wondered how one manually releases the springs on the spring brakes...
Thanks.
This was the first thing I learned bout my bus n went ahead n replaced that rear diaphragm while I was there, was only $6
Yeah, they call them 'pancakes' in the trucking world LOL. Definitely a bad day when they're all dry rotted and torn like any other rubber item on a vehicle. No good at all when it involves your brakes! 😳
I'm almost ready to move my non-running bus. It's an automatic transmission, and I only want to move it a couple hundred feet. Should I put it in neutral for that moving operation? Where would I look for an air input to charge the whole system with pressure? Thanks for your time and wisdom!
Neutral works fine for a short, slow move like that. You just would not want to tow it in neutral for any distance or at speed.
As far as the air system input, if one is present the locations aren't consistent. They are often near the front of the bus, even on a rear engine bus, for tow truck access. But I do have a rear engine bus with the air fitting in the back...go figure?
If you have one, I would look in the front.. behind the bumper or perhaps behind a little door.
@@RollingLiving Thank you sir....I'll just have a look all around for the air fitting...if I can find it, I might just charge the system so I have brakes while moving the bus...not too many flat spots on top of an Ozark mountain...would hate to lose the bus in the creek or lose my garage with a rolling bus! Otherwise, I'll have the bus securely connected to a cable and chain around a big oak or two. Should be fun!
@@Omarateastwind Well being able to air up the system so you have brakes is definitely the better option, if you can. 👍
Great information! So, will the front wheels turn freely or is there more to do before trying to move a bus? Thanks!
The front wheels will still turn. The parking brakes on your air brake system only lock the rear wheels. If you're just rolling the bus a short way, like on your property, this is all you have to do. If you're towing it, though, you want to disconnect the drive shaft to protect the transmission.
So if you release the spring brakes, does that mean that there is absolutely no way to apply braking force for when you're just moving the bus around your property? For instance hardly anyone's property is perfectly flat, and so the bus might keep going a ways after you pull/push it, unless you have a helper behind the wheel who can apply a little braking force somehow...
Yes, no brakes without air pressure. This is intended for towing, really. You're absolutely right about it rolling on!
Thanks. Is that the same on brakes on the trailers on tractor and trailers?
While the spring braking concept is the same, I don't know if the brake chambers on a trailer are the same style or not. I think I've even seen tandem chambers...maybe? But I've only had experience with bus and straight truck brakes.
Mercedes bad, Cummins good…
They won’t work on them because they no longer work with the Mercedes engines