Please help me with my air brake situation

[ManDogBus]

Originally Posted by Dbacks2k4

I would first reconnect the wheelchair lift if you can and see if the parking brakes release. That'll tell you for sure where your issue is. If they still don't release we have another problem to chase.

If they do release once the lift is reconnected, then you can go about removing the interconnect. Usually it means jumping a couple wires together somewhere to complete the circuit. I'm not an expert at tracing those out...

I reconnected the wheelchair lift and it is, as far as I can tell, operational. The motor moved the lift out, then I put it back in it's "stowed" position. This has not changed my parking brake issue.

[turf]

the parking brake and the service brake run off of different air circuits.

right now, if you park button doesnt stay in, you don't have air pressure on your parking brake side.

it could be a bad air valve, bad brake can.... something

try an id which tires, which brake is at fault.

[ManDogBus]

Working on this again today. I'll see if I can figure out any obvious signs of a problem, such as packrat bites, cracked, or leaking parts.

I would really like help removing the failsafes for my doors, does anyone here know where a resource about that might be?

Thanks again to everyone who has been helping so far.

[BamaBus]

Could emergency escape window removal have caused an issue? You said you searched but did you run across this https://www.skoolie.net/forums/f37/p...out-26675.html

[ManDogBus]

Originally Posted by BamaBus

Could emergency escape window removal have caused an issue?[/URL]

Thanks for the suggestion. My bus didn't have emergency windows or ceiling hatches.

I'll try to cross reference that post and see if I can find something similar.

As for my front door situation, the connects were not as simple as I thought, and it would take ~12 different connectors to trial and error. Won't have time for that today, so instead I put another panel on to cover the part that I raised.

[Crown_Guy]

I drove a VanHool with a wheelchair lift for a year or so and I quickly came to hate the wheelchair lift. It had many interlocks and sensors to prevent the bus from releasing it's parking brakes, going into gear, and also would randomly start flashing the 4-way flashers while driving and nothing I could do would stop them. Several different failure modes all designed to make the bus very uncomfortable to drive, if it would even move at all.

It turned out that the most likely culprit,(there were several actually) in most of these failures was a single magnetic sensor indicating the Lift door was completely closed and locked. If it got out of adjustment, which was depressingly easy, the bus was turned into a House because it couldn't be moved.

Similar symptoms to your E-brake button refusing to stay down when trying to release it. I'd say your trouble is related to any number of the overly complex inter-locking Interlocks all working to turn your vehicle into a Motel.

This is regarded by the Gov't Nannies as "Improving Safety". When in fact it creates deadly, deadly, circumstances for system failures and possible deaths in real life situations.

Have I mentioned how much I despise all the so called safety crap forced on perfectly fine vehicles designed to do their job efficiently, and safely.

You have an electrical problem and no doubts about that. This re-enforces, for the umpteenth time, Ad Nauseum, the First Rule of Bus Conversion Club. Don't Remove ANY WIRING!!! until you know what it's connected to, and then only one at a time to verify everything still works. Or Else. (you get results like yours).

You OWN it at this point. Not much for it but to figure it out. Good Luck. And this should teach you a lesson in going slow and easy. Learning from bad experiences, This is called gaining Wisdom. Welcome to the Club.

Rant Off.

[ManDogBus]

Rant indeed, not very productive or insightful. Thanks for your vigor and energy, but I think it was wasted in this instance.

I have been going slow, about as slow as I could handle. I have ADHD, and the urge to break/cut something for short term gain is constant.

[Crown_Guy]

Not Insightful Huh?? That's in the eyes of the reader obviously. You admitted to removing many wires in other places not related to the lift. Then that you removed wires related to the lift. Also, the door mechanism is most certainly NOT hydraulic at all but air powered. It's very obvious that you have a fixation on what YOU think is the problem and are not listening to any of the previous posters replies, and tips to follow, including mine. Your story is a very old one here and we are used to the efforts to educate and help new folks in their problems while having all relevant advise ignored and hearing the complaints of how we are meanies and don't understand what your problems are.

My points are very clear that you have a potential variety of wiring and sensor faults that are preventing the E-brake from releasing. That's my point and if you refuse to see it and ignore it instead to chase Packrats, Vermin, Ghosts, or other perceived Gremlins, then more power to you. All fine with me, you're the one not hearing what we're trying to tell you. Enjoy the mess and learn from your experience. I'm done.

[ManDogBus]

Originally Posted by Crown_Guy

Not Insightful Huh?? That's in the eyes of the reader obviously. You admitted to removing many wires in other places not related to the lift. Then that you removed wires related to the lift. Also, the door mechanism is most certainly NOT hydraulic at all but air powered. It's very obvious that you have a fixation on what YOU think is the problem and are not listening to any of the previous posters replies, and tips to follow, including mine. Your story is a very old one here and we are used to the efforts to educate and help new folks in their problems while having all relevant advise ignored and hearing the complaints of how we are meanies and don't understand what your problems are.

My points are very clear that you have a potential variety of wiring and sensor faults that are preventing the E-brake from releasing. That's my point and if you refuse to see it and ignore it instead to chase Packrats, Vermin, Ghosts, or other perceived Gremlins, then more power to you. All fine with me, you're the one not hearing what we're trying to tell you. Enjoy the mess and learn from your experience. I'm done.

I seem to have upset you, which was unintentional, I'm sorry.

I realized later that I accidentally wrote hydraulic, but am unable to edit my original post. I know it's not hydraulic, I made a vocab mistake.

I am reading everyone's suggestions, some I cannot attempt currently, so I am giving updates on what I am doing. I don't have a person to help me this week, so anything involving that has been put on hold.

The packrat situation is very real on my property. My personal vehicle has already been eaten (knock sensor wiring) before I realized they were a problem here. My bus had rat droppings on the tire, so I am not making up a problem or "chasing ghosts" as you are implying. Just relax a little, if you don't want to help me that's totally understandable, thanks for trying.

[Jolly Roger bus 223]

crown guy is very knowlegeable when you get into his area.
you can question him and get answers or you can not heed his advice and do what you want.
thats my opinion and if you want i have no issues with you expressing yours.

[turf]

im learning new stuff all the time.

this is the first interlock on a parking brake i've seen on the forum. usually it's a no start ignition because of an interlock, not a "no move" interlock.

i've pulled a tommy lift gate off the back of a truck because no such interlock was installed.

are you sure its an interlock? are you sure its electrical?

brakes are pneumatic and fail locked.

i'd verify air everywhere before chasing electrical.

if the dash valve doesnt stay down, have you disassembled it and cleaned it? is there an electric wire on it? if you unhook the electric wire, does the valve function?

[Sehnsucht]

Originally Posted by turf

im learning new stuff all the time.

this is the first interlock on a parking brake i've seen on the forum. usually it's a no start ignition because of an interlock, not a "no move" interlock.

Well with a wheelchair lift the engine may need to be idling to run the hydraulic pump so a no-start lockout is a non-starter (lol) but I can totally see a parking brake lockout fitting this instance. I had a semi truck that had a security lockout to prevent unauthorized drivers and it was triggered by the release of the parking brake. No code? As soon as you press the parking brake valve it would kill the engine. So it's important to remember and my unqualified opinion is that the brakes don't have a fault themselves but as Crown_Guy pointed out that numerous other interlocks that could have been unintentionally cut and ALL need to be restored or properly defeated in order to complete the circuit and allow the brakes to release. The fact that there's no audible air leak and it can achieve cut-out pressure but the valve immediately pops back out implies to me it's not an air system issue but a secondary influence linked into the parking brake valve.

[turf]

i googled "air brake interlock" and came up with this thread.

they at least show a picture of the air interlock, probably some nore good info for the OP.

https://www.skoolie.net/forums/f49/h...ove-32287.html

[ManDogBus]

Originally Posted by turf

are you sure its an interlock? are you sure its electrical?

brakes are pneumatic and fail locked.

i'd verify air everywhere before chasing electrical.

if the dash valve doesnt stay down, have you disassembled it and cleaned it? is there an electric wire on it? if you unhook the electric wire, does the valve function?

I do not know if it's an interlock, and I do not know if it's electrical. I know all three doors had an alarm that beeps if the door is open while the engine is idling. Checking for an interlock seemed like the easiest thing for my skills to diagnose or exclude for the time being. My wires are still there for the most part, just unplugged from their quick connectors. Electrical systems I understand more than brakes/engines/solenoids and other mechanics.

I haven't opened the dash, taken it apart, or cleaned it. That sounds like another option, but I'm unsure the likelihood since my bus is relatively new.

Originally Posted by Sehnsucht

it's important to remember and my unqualified opinion is that the brakes don't have a fault themselves but as Crown_Guy pointed out that numerous other interlocks that could have been unintentionally cut and ALL need to be restored or properly defeated in order to complete the circuit and allow the brakes to release. The fact that there's no audible air leak and it can achieve cut-out pressure but the valve immediately pops back out implies to me it's not an air system issue but a secondary influence linked into the parking brake valve.

This last sentence made sense to me, but someone had mentioned that if it pops out then that means it doesn't have air, and I admit I don't know brakes.

The system definitely has air, the chair has air lifts and works great. Before I had capped off the front door tubing, it leaked and whipped around a little (it's capped now). I think there is a strong possiblity there are more failsafes/interlocks/etc that I need to eliminate. The probablem could definitely be multiple issues.

Originally Posted by turf

i googled "air brake interlock" and came up with this thread.

they at least show a picture of the air interlock, probably some nore good info for the OP.

Thanks turf! I think this will help significantly. if I don't have something that looks something like this then I can potentially cross one thing off for now. Some people have suggested it could be in many different places, so it will probably take a lot of scouting.

[ManDogBus]

Poked around awhile in the bus and found a few things.

My bus doesn't have a door related ignition interlock, I was able to start the bus with all doors open
The alarms for the doors being open still work when starting and running the bus.
My bus doesn't have any obvious signs of wires that had been chewed, no pieces, fraying, etc

I think I'm to a point of assuming it is more likely brake related than electric related, but I need to check my new photos with other's interlock devices once I get to my computer.

Attached below is under my hood and under the right rear tire

(edit) I'm also attaching a screen grab (triple photo below- not my bus) from another person discussing a similar wheelchair interlock on a thread that turf linked. Under the hood looks really similar (3rd photo (other bus) is similar to the photo with the purple circle- my bus), especially compared to the under the hood photo of a non-interlocked bus.

[BamaBus]

Originally Posted by ManDogBus

Poked around awhile in the bus and found a few things.

My bus doesn't have a door related ignition interlock, I was able to start the bus with all doors open
The alarms for the doors being open still work when starting and running the bus.
My bus doesn't have any obvious signs of wires that had been chewed, no pieces, fraying, etc

I think I'm to a point of assuming it is more likely brake related than electric related, but I need to check my new photos with other's interlock devices once I get to my computer.

Attached below is under my hood and under the right rear tire

You may be headed in the right direction. I don't know if the connection under the bus is what you need. If you compare your pic with the one Pizote posted then you may see the difference. It seems quite simple to bypass, but I don't have to drive the bus. Since you disconnected the wiring and removed the valve and such above the exit door this may be the way to proceed.

[ManDogBus]

Originally Posted by BamaBus

You may be headed in the right direction. I don't know if the connection under the bus is what you need. If you compare your pic with the one Pizote posted then you may see the difference. It seems quite simple to bypass, but I don't have to drive the bus. Since you disconnected the wiring and removed the valve and such above the exit door this may be the way to proceed.

Sorry I'm confused, which is the right direction?
I'm also unsure where the photo "Pizote posted" is.


It does seem simple to bypass an interlock device, I am unsure if I have one and what it would be connected to. Once I indentify if I have one and what it looks like I can trace and test those wires. My front door is currently the only thing "unplugged" but it doesnt have the same solenoid style failsafe device that the back doors have.

(edit) I attached a photo of my front door pneumatic assembly. These purple arrows could indicate the power cables that might need to be grounded in able to unlock the brakes. I suppose it could be checking for pressure/lack of on the right device or extension or retraction on the left.

[ewo1]

Originally Posted by ManDogBus

I seem to have upset you, which was unintentional, I'm sorry.

I realized later that I accidentally wrote hydraulic, but am unable to edit my original post. I know it's not hydraulic, I made a vocab mistake.

I am reading everyone's suggestions, some I cannot attempt currently, so I am giving updates on what I am doing. I don't have a person to help me this week, so anything involving that has been put on hold.

The packrat situation is very real on my property. My personal vehicle has already been eaten (knock sensor wiring) before I realized they were a problem here. My bus had rat droppings on the tire, so I am not making up a problem or "chasing ghosts" as you are implying. Just relax a little, if you don't want to help me that's totally understandable, thanks for trying.

To the o/p,
Consider this a mini rant…

Did you ever look at the electrical diagrams I uploaded, for you!
While field vermin are a consideration to consider you still have to do old fashion troubleshooting. Ghosts…. Never mind…

Take a look at page 374 and also the next 10 pages after that.
Those diagrams clearly show how the circuit is wired up !

You need to determine if the diagrams are similar to what your bus wiring might be and if they are reasonably similar, work off of that.

Your bus most likely does have a relay interlock and you need to locate that circuit. Once you find it then use the diagram to bypass it.

You said your lift works, great…but who cares. You need to identify the circuit in question!

[BamaBus]

Originally Posted by ManDogBus

Sorry I'm confused, which is the right direction?
I'm also unsure where the photo "Pizote posted" is.


It does seem simple to bypass an interlock device, I am unsure if I have one and what it would be connected to. Once I indentify if I have one and what it looks like I can trace and test those wires. My front door is currently the only thing "unplugged" but it doesnt have the same solenoid style failsafe device that the back doors have.

(edit) I attached a photo of my front door pneumatic assembly. These purple arrows could indicate the power cables that might need to be grounded in able to unlock the brakes. I suppose it could be checking for pressure/lack of on the right device or extension or retraction on the left.

Sorry but I sometimes find it hard to relay what I am thinking in print. The metal "shelf" is what is in the thread I linked to you earlier. The valve on the right (as in shown in your pic) was removed in the thread by Pizote. This is supported by others in the same thread (see the sure_ whynot post#21) also nuttbus on instagram. The only issue is what to do with the two extra lines. The exit door may have been the problem but your solution is the valve (as I see it).

[ManDogBus]

Originally Posted by ewo1

To the o/p,
Consider this a mini rant…

Did you ever look at the electrical diagrams I uploaded, for you!
While field vermin are a consideration to consider you still have to do old fashion troubleshooting. Ghosts…. Never mind…

Take a look at page 374 and also the next 10 pages after that.
Those diagrams clearly show how the circuit is wired up !

You need to determine if the diagrams are similar to what your bus wiring might be and if they are reasonably similar, work off of that.

Your bus most likely does have a relay interlock and you need to locate that circuit. Once you find it then use the diagram to bypass it.

You said your lift works, great…but who cares. You need to identify the circuit in question!

I did look at them and saved those to my computer for later use. Those wiring diagrams are too abstract for my untrained mind, it looks like total gibberish , and it's much harder for me to understand if that is what mine looks like especially when I don't know electrical diagram shorthand. If these printed numbers/letters are the names on the wires, I can definitely check that, but I feel like wires could be any color/code that they might want to use in the moment.

I'm heading to a BBQ and will work on this again tomorrow.

Really, thanks everyone for your help so far!