Reply
 
Thread Tools Display Modes
 
Old 08-17-2016, 08:08 AM   #21
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,140
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
I only say put it on stands to better be able to level it... but no I see the air ride just sits on the stops when flat.. my bus loses its air as noted above so its on the stops most anytime its parked..

-Christopher
cadillackid is offline   Reply With Quote
Old 12-14-2016, 02:39 PM   #22
Bus Nut
 
Join Date: Oct 2016
Location: Pensacola and Crystal River, FL
Posts: 554
Year: 1998
Coachwork: AmTran International
Chassis: 3800
Engine: Navistar 7.6L
About the rear air ride suspension............................

Is there a means of more air pressure being added as the loading inside the bus increases?

So that nothing makes contact with things they should not, like bump stops and tires hitting wheel wells, etc. ?
DoubleO7 is offline   Reply With Quote
Old 12-14-2016, 03:25 PM   #23
Bus Nut
 
AlleyCat67's Avatar
 
Join Date: Oct 2013
Location: Music City USA
Posts: 737
Year: 2005
Coachwork: Thomas
Chassis: Freightliner
Engine: Detroit MBE906
Rated Cap: 72
Even if the air ride goes completely flat you won't have to worry about anything rubbing that shouldn't because there is a mechanical stop to prevent it from going down past a certain point.
__________________
My bus - Jasmine - External Build Website - YouTube Channel - TN/KY Meetup Group
As a level 1 burglar, Bilbo got a pony when he accompanied the level 60 dwarves on the Smaug the Dragon raid. Those powerlevelers probably invited him solely so he could trigger fellowship attacks for them.
AlleyCat67 is offline   Reply With Quote
Old 12-14-2016, 03:36 PM   #24
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,140
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
most of them are pretty simple.. you can adjust the height that it sits.. if you set ot to a higher height it will have to keep higher pressure as you load it.. or I should say higher in relation to if you leave the height at its current setting.. makingthe ride much stiffer.. if your bus is sagging when you lod it down then the air ride is not working as it should. most of the are a simple lever-arm from the suspension to the bus frame to hold a height.. its a simple air valve connected to the lever arm....

there are published specs in the service manuals for what its recommended setting is.. too high setting and the ride is way stiff and increases the chances of wheel bounce over bumps... too low and the suspension is softer and more likely to bottom out on bumps...
-Christopher
cadillackid is offline   Reply With Quote
Old 12-14-2016, 03:37 PM   #25
Bus Nut
 
Join Date: Oct 2016
Location: Pensacola and Crystal River, FL
Posts: 554
Year: 1998
Coachwork: AmTran International
Chassis: 3800
Engine: Navistar 7.6L
N/A

I am looking to find out if more air pressure is added to maintain a certain ride height, automatically.

When loaded with cargo versus not loaded.
DoubleO7 is offline   Reply With Quote
Old 12-14-2016, 03:40 PM   #26
Bus Nut
 
Join Date: Oct 2016
Location: Pensacola and Crystal River, FL
Posts: 554
Year: 1998
Coachwork: AmTran International
Chassis: 3800
Engine: Navistar 7.6L
Thanks cad,
I was thinking there was some sort of "ride height maintainer valve or regulator" somewhere.
DoubleO7 is offline   Reply With Quote
Old 12-14-2016, 03:42 PM   #27
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,140
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
yes.. thats the valve I mentioned..its at the back of the bus and is a simple lever arm attached to the suspension and the bus frame.. it simply maintains height.. whatever load is applied in the bus.. if the rear lowers down then more air is added to maintain that height .. its typically all mechanical, no electricals.
-Christopher
cadillackid is offline   Reply With Quote
Old 12-18-2016, 10:08 AM   #28
Bus Crazy
 
milkmania's Avatar
 
Join Date: May 2015
Location: Oklahoma aka "God's blind spot"
Posts: 2,361
Year: 1989
Coachwork: 1853FC International/Navistar
Chassis: 35' Retired Air Force Ambulance
Engine: DT466, MT643
Rated Cap: 6 souls and a driver
Quote:
Originally Posted by cadillackid View Post
yes.. thats the valve I mentioned..its at the back of the bus and is a simple lever arm attached to the suspension and the bus frame.. it simply maintains height.. whatever load is applied in the bus.. if the rear lowers down then more air is added to maintain that height .. its typically all mechanical, no electricals.
-Christopher
My suburban uses a very similar setup, as did the limousine... Put 10 people back there for about 20 minutes, then have them all get out. The bumper was about 8 inches higher, till it balanced out.
__________________
I once complained I had no shoes....
Until I met a man with no feet
milkmania is offline   Reply With Quote
Old 12-18-2016, 11:33 AM   #29
Bus Nut
 
Join Date: Oct 2016
Location: Pensacola and Crystal River, FL
Posts: 554
Year: 1998
Coachwork: AmTran International
Chassis: 3800
Engine: Navistar 7.6L
Yea, way back in 1988 I ordered a brand new Jeep pickup.
Then I promptly replaced the rear axle with a Ford nine inch.

It had a valve with a lever on the body with a rod going down to the axle.
It was a brake bias balancing valve so that with no cargo, the brakes were restricted. And with more cargo the valve opened for more braking.

I guess it was a type of mechanical anti-lock brake system.

Off subject but that is what came to mind with the air ride system mentioned.
DoubleO7 is offline   Reply With Quote
Old 12-18-2016, 04:34 PM   #30
Mini-Skoolie
 
Join Date: Aug 2015
Location: Redding, CA
Posts: 17
Year: 2002
Coachwork: BlueBird Comm'l shell
Safety issue...your air tanks should not go empty because of leaking air suspension. There is a "pressure protection valve" on an air tank that supplies the "height control valve". This valve is important because it "protects" the pressure in your air system from being depleted lower than 70/80/90 pounds or so. That way if you have an air ride system problem (blown bag, major leak, etc) your air system is "protected" so that you still have brakes...really important!!

Here is how to check if your pressure protection valve works...disconnect the air line that supplies your height control valve....the air should leak down to no less than about 70 psi on one or more of your air tanks.

If the air comes out and then stops and you still have at least 70psi in the tank, your pressure protection valve works. If your air leaks out until your air tank is damn near empty, you need a new pressure protection valve.

You can Google pressure protection valve or Sealco 140270, 140280 or 140290...the last two number of each part number is the psi rating at which this valve shuts off.
MrDaveG is offline   Reply With Quote
Old 12-18-2016, 05:18 PM   #31
Almost There
 
Join Date: Aug 2014
Location: Oklahoma
Posts: 85
Year: 1984
Coachwork: Ward/Amtram
Chassis: International 36ft
Engine: DT466 w/ Allison MT643
Quote:
Originally Posted by MrDaveG View Post
Safety issue...your air tanks should not go empty because of leaking air suspension. There is a "pressure protection valve" on an air tank that supplies the "height control valve". This valve is important because it "protects" the pressure in your air system from being depleted lower than 70/80/90 pounds or so. That way if you have an air ride system problem (blown bag, major leak, etc) your air system is "protected" so that you still have brakes...really important!!

Here is how to check if your pressure protection valve works...disconnect the air line that supplies your height control valve....the air should leak down to no less than about 70 psi on one or more of your air tanks.

If the air comes out and then stops and you still have at least 70psi in the tank, your pressure protection valve works. If your air leaks out until your air tank is damn near empty, you need a new pressure protection valve.

You can Google pressure protection valve or Sealco 140270, 140280 or 140290...the last two number of each part number is the psi rating at which this valve shuts off.
If the vehicle doesnt have air brakes or air-anything safety critical, would it necesarrily have this valve?
dalez is offline   Reply With Quote
Old 12-18-2016, 05:25 PM   #32
Bus Crazy
 
milkmania's Avatar
 
Join Date: May 2015
Location: Oklahoma aka "God's blind spot"
Posts: 2,361
Year: 1989
Coachwork: 1853FC International/Navistar
Chassis: 35' Retired Air Force Ambulance
Engine: DT466, MT643
Rated Cap: 6 souls and a driver
Quote:
Originally Posted by MrDaveG View Post
Safety issue...your air tanks should not go empty because of leaking air suspension. There is a "pressure protection valve" on an air tank that supplies the "height control valve". This valve is important because it "protects" the pressure in your air system from being depleted lower than 70/80/90 pounds or so. That way if you have an air ride system problem (blown bag, major leak, etc) your air system is "protected" so that you still have brakes...really important!!

Here is how to check if your pressure protection valve works...disconnect the air line that supplies your height control valve....the air should leak down to no less than about 70 psi on one or more of your air tanks.

If the air comes out and then stops and you still have at least 70psi in the tank, your pressure protection valve works. If your air leaks out until your air tank is damn near empty, you need a new pressure protection valve.

You can Google pressure protection valve or Sealco 140270, 140280 or 140290...the last two number of each part number is the psi rating at which this valve shuts off.

I've got 2 separate gauges for brakes & bags...
And I can dump my bags with a switch, but that switch is wired to close on the run side of the ignition.
Ignition off: can dump bags
Ignition on: cannot dump bags, but can leave switch in dump position and they'll only dump when I turn the key off.
__________________
I once complained I had no shoes....
Until I met a man with no feet
milkmania is offline   Reply With Quote
Old 12-18-2016, 07:33 PM   #33
Mini-Skoolie
 
Join Date: Aug 2015
Location: Redding, CA
Posts: 17
Year: 2002
Coachwork: BlueBird Comm'l shell
Quote:
Originally Posted by dalez View Post
If the vehicle doesnt have air brakes or air-anything safety critical, would it necesarrily have this valve?
I don't know
MrDaveG is offline   Reply With Quote
Old 12-18-2016, 07:37 PM   #34
Mini-Skoolie
 
Join Date: Aug 2015
Location: Redding, CA
Posts: 17
Year: 2002
Coachwork: BlueBird Comm'l shell
Quote:
Originally Posted by milkmania View Post
I've got 2 separate gauges for brakes & bags...
And I can dump my bags with a switch, but that switch is wired to close on the run side of the ignition.
Ignition off: can dump bags
Ignition on: cannot dump bags, but can leave switch in dump position and they'll only dump when I turn the key off.
No question here...?

I can see why the bags may not be deflated during "run"...sometimes so a "less than experienced driver" doesn't drive around with the bags flat...kinda one of those idiot proof things.

Most vehicles with air brakes after the late 70s have a dual air brake system and that is why there are two air pressure gauges....buses might have a different set of rules from big trucks though. If you only have two gauges and one of them is truly for your suspension, does the other gauge have two needles (one white and one orange/red)?
MrDaveG is offline   Reply With Quote
Old 12-19-2016, 11:35 PM   #35
Mini-Skoolie
 
Join Date: Jul 2016
Posts: 54
There's usually an air relay valve on the front and on the rear to protect against bag failure and get the vehicle back to the workshop. As well as the main valve. Just listen for the various pops as they build pressure.

The valves are generally serviceable, may need a new gasket. Otherwise they're extremely simple mechanically and can be cleaned easy enough. did the one on mine recently.
retiredChemist is offline   Reply With Quote
Old 12-20-2016, 11:45 AM   #36
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,140
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
my bus that has no air brakes but has air ride and air seat has protection valves installed at the outlet of the tank going to the air ride and also the outlet going to the air seat..

it has NO air dryer and only has a SINGLE tank, no wet tank.

it has an automatic drain valve on the tank which operates when the governor calls for air.. so it pumps up, governor cuts off the compressor.. air pressure goes down to 90, drain valve opens..sometimes long, sometimes short depending on moisture? and then closes.. air pumps back up to 120...

being in ohio in the cold means that whole thing freezes.. this AM my compressor went up to 150 and a Pop-off valve tripped.. I could hear it.. I think its on the tank itself..

now that its warmer out.. sun is out and in upper 20s.. it all works nornal again..

I think I need to replace the drain valve wit ha wet tank and an air dryer since I drive the bus in ohio? even though I dont have air brakes?

or just take this bus to florida and only use it there?

-Christopher
cadillackid is offline   Reply With Quote
Old 12-22-2016, 06:46 AM   #37
Mini-Skoolie
 
Join Date: Jul 2016
Posts: 54
Or run a coolant loop around the tank. Keep the air above freezing.
retiredChemist is offline   Reply With Quote
Old 12-22-2016, 06:58 AM   #38
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,140
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
Quote:
Originally Posted by retiredChemist View Post
Or run a coolant loop around the tank. Keep the air above freezing.
I had thought about wrapping the tank in a heated mat, like one of the outdoor rated heated door-mats..

Bendix makes a heated auto-drain valve..

im more inclined to do the project the accepted way which would be install an air dryer and get rid of the auto-drain valve altogether..

the nice little compact wabco dryer would work for this system since its not a high air volume usage system being only air ride and seat.

I cant think of anything else air operated that id install on the bus other than I'll install a quick connect so I can air up the tires using onboard air instead of external compressors.. external compressor is fine when im in ohio as i have a great shop setup but when im in florida I dont.

** or **

I could just drive the bus in WARM places like florida

-Christopher
cadillackid is offline   Reply With Quote
Old 12-22-2016, 07:30 AM   #39
Bus Nut
 
Join Date: Oct 2016
Location: Pensacola and Crystal River, FL
Posts: 554
Year: 1998
Coachwork: AmTran International
Chassis: 3800
Engine: Navistar 7.6L
Quote:
Originally Posted by cadillackid View Post
I
I cant think of anything else air operated that id install on the bus other than I'll install a quick connect so I can air up the tires using onboard air instead of external compressors..

-Christopher
You might want to add these some day................
Attached Images
File Type: jpg Leslie9.jpg (141.3 KB, 6 views)
DoubleO7 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 06:42 AM.


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