Reply
 
Thread Tools Display Modes
 
Old 10-27-2017, 09:12 PM   #1
Almost There
 
Join Date: Mar 2017
Location: SLC, UT
Posts: 71
Year: 2003
Coachwork: Thomas
Chassis: Freightliner
Engine: MBE 904
Air brakes questions

So I have a 2003 Thomas/frieghtliner FS65 shorty. It has airbrakes. I want to hook up an air ride drivers seat. I was just going to tap off the hose I disconnected from the stop sign. I'm not sure what size hose that seat is going to require, but if I have to run a bigger hose I'd have to release the pressure in the tank to put a fitting on. How exactly do the air brakes work? If I release the air in the tanks, will the brakes release? I don't have a "park" on my transmission. It's just neutral and the air emergency break. My wheels will be chaulked obviously, but I'm curious if you were parked on a hill and there was a leak in the system. It seems as though there'd have to be some kind of fail safe. Does the lever close a valve and keeps the pressure to the brakes? sorry im rambling.
Gatorbait is offline   Reply With Quote
Old 10-27-2017, 09:26 PM   #2
Bus Geek
 
Join Date: Sep 2017
Location: Owasso, OK
Posts: 2,627
Year: 1999
Coachwork: Thomas
Chassis: Saf-T-Liner MVP ER
Engine: Cummins 6CTA8.3 Mechanical MD3060
Rated Cap: 46 Coach Seats, 40 foot
Quote:
Originally Posted by Gatorbait View Post
So I have a 2003 Thomas/frieghtliner FS65 shorty. It has airbrakes. I want to hook up an air ride drivers seat. I was just going to tap off the hose I disconnected from the stop sign. I'm not sure what size hose that seat is going to require, but if I have to run a bigger hose I'd have to release the pressure in the tank to put a fitting on. How exactly do the air brakes work? If I release the air in the tanks, will the brakes release? I don't have a "park" on my transmission. It's just neutral and the air emergency break. My wheels will be chaulked obviously, but I'm curious if you were parked on a hill and there was a leak in the system. It seems as though there'd have to be some kind of fail safe. Does the lever close a valve and keeps the pressure to the brakes? sorry im rambling.
The air pressure in an air-brake system holds the brakes "Off". If the pressure is released, the brakes engage.

There are two brake systems in play. A proportional system that works when you press the brake pedal (it's actually a valve), that applies the brakes progressively.

The parking brake is what is called a "Spring brake". Air pressure holds the brakes off until you shift the yellow brake valve. That releases the pressure that is holding back an extremely strong spring. When the spring is released it engages the rear brakes.

You need an air pressure of between 90 and 120 psi for the brakes to work effectively. Below 60 psi the spring brake will engage and you are not going anywhere.

There should be a valve on the bottom of the air cylinder under the bus where you can manually release the pressure if you need to. It's also used to blow out any water that might have collected.
__________________
Steve Bracken

Build Thread
Twigg is offline   Reply With Quote
Old 10-27-2017, 10:47 PM   #3
Almost There
 
Join Date: Mar 2017
Location: SLC, UT
Posts: 71
Year: 2003
Coachwork: Thomas
Chassis: Freightliner
Engine: MBE 904
That's the exact information I was looking for. Thank you so much. That's a great peace of mind.
Gatorbait is offline   Reply With Quote
Old 10-28-2017, 03:46 AM   #4
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 1,592
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
This is why I prefer air brakes (in addition to being accustomed to driving with them). My driveway is not flat and the spring brakes provide a *LOT* of holding power.
Brad_SwiftFur is offline   Reply With Quote
Old 10-28-2017, 09:56 PM   #5
Skoolie
 
bubb, the real one's Avatar
 
Join Date: Dec 2014
Location: central texas
Posts: 132
Year: 1990
Coachwork: Thomas/International
Chassis: 3700
Engine: 7.3
Rated Cap: 72
Line

My bus uses 1/4 inch NPT fittings and air hose, my research says to use loctite 545 glue on all connections
bubb, the real one is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 04:34 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×