removing stop sign assembly

[easygoing]

I am new to this forum and hoping to use it often for questions throughout my vandura/ward bus fixing. I recently purcharsed an 85 gmc vandura/ward short bus and have been cleaning it up removing most of the school bus things since it wont be used for that. I removed the stop sign assembly and noticed that when I manually pulled out the stop sign I could hear air, once removed from the side I disconnected the hose and capped it off. My question is should I have left the hose open to pull air in or is capping it off okay? The reason I ask is when the bus is parked and off and I apply the brake the pedal shutters and a squeal comes from under the hood. I havent taken it for a spin yet since removing the sign to make sure the bus stops okay, thought I would check here first. Thanks for reading, hope to get some feedback soon!!

[crazycal]

Do you have air brakes? I've had one stop sign that was electric and one that was powered by air.

[easygoing]

Yes I am pretty certain they are air brakes there is a hose that went from the stop sign bracket to a tank underneath and a hose coming from that tank to the master cylinder. Assuming I followed the correct hose. I will check again to make sure, first timing owning a bus so I am learning as I go, bare with me!

[easygoing]

After doing some research on air brakes there is no way that I have them considering I have mater cylinder and brake fluid correct? I think what I need to do is take it out for a spin and see if anything feels different than when the sign was hooked up. I will repost once that is done. I just dont see how anything could have changed, all i did was disconnect the hose that looked to be attached to a bladder behind the stop sign assembly and capped it off. May be nothing just wanted to see if anyone has experienced this before.

[chev49]

if its an air operated sign, like mine, just capping it off will be fine.
course could also be vacuum if in hydraulic master cy, which capping off would also be fine.

[easygoing]

Yep seems to stop just fine, doesn't seem like I have anything to worry about. Thanks for your help!

[bansil]

Are you going to post pics in a build thread?we like pics like some kids like windows ooops I apoligize to all the starving kids in Etheopia.......

[vegabond]

Originally Posted by chev49

if its an air operated sign, like mine, just capping it off will be fine.
course could also be vacuum if in hydraulic master cy, which capping off would also be fine.

Howdy! I am following the advice on this thread but had a another question.
I took off the air line from the stop sign. It goes to a “T.” Then the line goes to the hydraulic system (? I’m assuming/guessing on the name) I also see that the attached hose from the “T” goes to the air seat. Then another line goes under the bus to somewhere else (it’s been so hot in TX that I haven’t got to check under the bus yet). I have air doors that I plan on keeping. For my question- how do I keep my air seat working and my air door working properly ? I’m confused on how all of this works. I see that the line says air brakes and I panicked thinking about the actual air brakes for the main bus… would that be attached to the same area? Surely not, I hope.

(I circled the system because that is what I am referring to as the hydraulic system above)
I’ll post pics of what the visual is of my question 🚌

Ms. Cody

[TheHubbardBus]

It's not part of a hydraulic system, as that would indicate the use of fluids to transfer force. Pneumatic would be a more appropriate term, which indicates a system utilizing air/gas.

The air system of the bus is used to primarily actuate the brakes, and secondarily to operate air accessories (door, seat, sign in your case, etc). The system is in fact separated along these lines, in a manner of speaking, so that if a leak develops in the secondary system, it should not have an immediate / catastrophic impact on your ability to safely stop the bus, assuming everything is functioning properly. It's a bit more complicated than that, but without going into unnecessary details, that's pretty much the way it works. A secondary-side leak will only bleed down so far before it stops taking air away from the system at large. That's not to say you want any leaks. Just that if you were to have one on the secondary side it wouldn't result in you immediately losing the ability to brake.

Any air accessory that you don't want / need can easily be removed by simply capping off the air line feeding it. If it's a T-fitting, and the rest of the stuff downstream of it you want to remain operational, either cap the end of the 'T', replace it with a 2-way union, or replace the entire line segment to exclude the 'T'. You can use either compression or push-to-connect fittings, but they should be DOT approved for use in air brake systems.

FWIW, IMO you should at a bare minimum understand the basics of how your air brake system operates, so that's something you might want to study up on. In order to use it safely, you really need to understand how it works, and it works absolutely nothing like the (hydraulic) brakes on vehicles you're likely more used to driving. Lots of resources on this site via the search feature that you can use to self-educate. Know how your brakes work, know how to perform a pre-trip inspection of the air brake system, and do it.

[vegabond]

Thank you so much! This was great information. I fully understand what you were describing. I appreciate the quick response!

[vegabond]

Originally Posted by TheHubbardBus

It's not part of a hydraulic system, as that would indicate the use of fluids to transfer force. Pneumatic would be a more appropriate term, which indicates a system utilizing air/gas.

The air system of the bus is used to primarily actuate the brakes, and secondarily to operate air accessories (door, seat, sign in your case, etc). The system is in fact separated along these lines, in a manner of speaking, so that if a leak develops in the secondary system, it should not have an immediate / catastrophic impact on your ability to safely stop the bus, assuming everything is functioning properly. It's a bit more complicated than that, but without going into unnecessary details, that's pretty much the way it works. A secondary-side leak will only bleed down so far before it stops taking air away from the system at large. That's not to say you want any leaks. Just that if you were to have one on the secondary side it wouldn't result in you immediately losing the ability to brake.

Any air accessory that you don't want / need can easily be removed by simply capping off the air line feeding it. If it's a T-fitting, and the rest of the stuff downstream of it you want to remain operational, either cap the end of the 'T', replace it with a 2-way union, or replace the entire line segment to exclude the 'T'. You can use either compression or push-to-connect fittings, but they should be DOT approved for use in air brake systems.

FWIW, IMO you should at a bare minimum understand the basics of how your air brake system operates, so that's something you might want to study up on. In order to use it safely, you really need to understand how it works, and it works absolutely nothing like the (hydraulic) brakes on vehicles you're likely more used to driving. Lots of resources on this site via the search feature that you can use to self-educate. Know how your brakes work, know how to perform a pre-trip inspection of the air brake system, and do it.

Hello! I removed the air line to the stop arm and stop signs - put the cap on the ends of the 'T' just like you had stated. After removing the lines that I no longer needed, I wanted to know if I can eliminate the regulator or if I should keep it? I want to have my air seat still. If I need to keep it for the air seat, I have noticed that the regulator has 2 black wires from the back of it and I know one went to the solenoid but I do not remember where the other one went..Can you help me please?