Reply
 
Thread Tools Display Modes
 
Old 04-08-2019, 05:22 PM   #1
Mini-Skoolie
 
Join Date: Sep 2016
Location: TEXAS
Posts: 62
Year: 1999
Chassis: MVP RE
Engine: 5.9 Cummins
Air bags or shocks

I have a 1999 Thomas RE with 5.9 engine. I think either the air bags and/or the shocks need to be replaced on this bus. Two years ago when I bought the bus the school bus mechanic said that the suspension was ok. But it just look like the tire is too close to the wheel well. All of the seats are out except 7 up front.

The bus seem to drive ok but I'm not a professional. Look at the attached picture and please tell me what you think. The bus does not have leaf springs, just two air bags and two shocks in the rear. The front have leaf springs.
Attached Images
File Type: jpg IMG_2063.jpg (119.5 KB, 23 views)
budbud7 is offline   Reply With Quote
Old 04-08-2019, 05:34 PM   #2
Bus Nut
 
ermracing's Avatar
 
Join Date: Jun 2018
Location: Unity, NH
Posts: 434
Year: 2003
Coachwork: Bluebird
Chassis: International 3800
Engine: DT466E (195hp, 520tq)
Rated Cap: 29,000
The shocks don't hold the weight of the bus, the springs (leaf, coil or air) do that. It may not be the bags, but there is a leak in the boat somewhere.... Do they pump up after the bus is running? If they do, how long does it take for them to drop after it's shut off? Can you hear the leak?
__________________
Dave
ermracing is offline   Reply With Quote
Old 04-08-2019, 05:54 PM   #3
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 1,948
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
Start the bus. Let the air system charge. Suspension air bags should inflate when air pressure reaches 80 (maybe as low as 60).


If the air pressure reaches 100+ and the air bags are still flat, you have a problem to diagnose. Any hissing air pressure is probably bad, but most parts are reasonably easy to fix. Suspension "leveling valve" is a fairly common failure and easily replaced.
Brad_SwiftFur is offline   Reply With Quote
Old 04-08-2019, 06:19 PM   #4
Mini-Skoolie
 
Join Date: Sep 2016
Location: TEXAS
Posts: 62
Year: 1999
Chassis: MVP RE
Engine: 5.9 Cummins
I have never heard any air leak. But then I have not been seeking one. The height does not change when the system is fully charged. I will charge it up and get under there and search. Also I will check out the leveling valve. Most likely its inline, near the bags. Is the valve electrical or purely mechanical?

Right now, the ground in my part of Texas is saturated!!
budbud7 is offline   Reply With Quote
Old 04-08-2019, 06:53 PM   #5
Bus Nut
 
ermracing's Avatar
 
Join Date: Jun 2018
Location: Unity, NH
Posts: 434
Year: 2003
Coachwork: Bluebird
Chassis: International 3800
Engine: DT466E (195hp, 520tq)
Rated Cap: 29,000
The leveling valve on ours is between the bags, to the rear of the diff. Pretty easy to spot once you get under there, just follow the levers and stuff. Hopefully it's something simple like that.
__________________
Dave
ermracing is offline   Reply With Quote
Old 04-08-2019, 07:36 PM   #6
Site Team
 
Johnny Mullet's Avatar
 
Join Date: Oct 2017
Location: Ashtabula, Ohio
Posts: 1,376
Year: 1996
Coachwork: Thomas
Chassis: International
Engine: T444E 7.3L
I totally suspect a bad leveling valve or linkage to the valve.
Johnny Mullet is offline   Reply With Quote
Old 04-08-2019, 08:34 PM   #7
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 1,948
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
Either the leveling valve (or associated pieces) need some work, or perhaps the leveling valve isn't getting air pressure - don't overlook that possibility.
Brad_SwiftFur is offline   Reply With Quote
Old 04-09-2019, 02:08 AM   #8
Bus Geek
 
Join Date: Sep 2015
Posts: 2,702
Year: 2002
Coachwork: Thomas Built Bus
Chassis: Freightliner FS65
Engine: Caterpillar 3126E Diesel
Rated Cap: 71 Passenger- 30,000 lbs.
Quote:
Originally Posted by Brad_SwiftFur View Post
Either the leveling valve (or associated pieces) need some work, or perhaps the leveling valve isn't getting air pressure - don't overlook that possibility.

Good point. We had to replace the valve that comes out of the tank and feeds the air springs. Ours was filling up every once and a while. It was nice when full, but we experienced vary nasty jolts when the rear axle hit the bump stops.


So, there is the compressor, the tank, the valve on the tank, the air lines, the leveling valve, the self-adjusting arm that attaches between the rear axle and the leveling valve ... and the air springs to be examined.
Native is offline   Reply With Quote
Old 04-16-2019, 05:00 PM   #9
Mini-Skoolie
 
Join Date: Sep 2016
Location: TEXAS
Posts: 62
Year: 1999
Chassis: MVP RE
Engine: 5.9 Cummins
Quote:
Originally Posted by Johnny Mullet View Post
I totally suspect a bad leveling valve or linkage to the valve.
Sunday I was able to get under the bus and I did find a valve and some linkage. It appears that 1/4" rod with 1/4" rubber tubing makes up the linkage. The rubber tubing is broken up. Its attached with small hose clamps. Do you know if this is a stock arrangement (the hose/hose clamps) or is it a temporary fix.

There still might be an air leak because I didn't get that far in checking things out.
Attached Images
File Type: jpg IMG_2372.JPG (129.0 KB, 34 views)
File Type: jpg IMG_2374.JPG (114.9 KB, 37 views)
budbud7 is offline   Reply With Quote
Old 04-16-2019, 06:26 PM   #10
Bus Geek
 
Tango's Avatar
 
Join Date: Mar 2011
Location: Houston, Texas
Posts: 8,462
Year: 1946
Coachwork: Chevrolet/Wayne
Chassis: 1- 1/2 ton
Engine: Cummins 4BT
Rated Cap: 15
Definitely a Jake-Leg job!
Tango is offline   Reply With Quote
Old 04-16-2019, 06:57 PM   #11
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 1,948
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
Quote:
Originally Posted by budbud7 View Post
Sunday I was able to get under the bus and I did find a valve and some linkage. It appears that 1/4" rod with 1/4" rubber tubing makes up the linkage. The rubber tubing is broken up. Its attached with small hose clamps. Do you know if this is a stock arrangement (the hose/hose clamps) or is it a temporary fix.

There still might be an air leak because I didn't get that far in checking things out.
Quote:
Originally Posted by Tango View Post
Definitely a Jake-Leg job!

I've seen more than one truck come like that from the factory! Replace rubber tubing, and you're back in business.
Brad_SwiftFur is offline   Reply With Quote
Old 04-16-2019, 06:57 PM   #12
Mini-Skoolie
 
Join Date: Oct 2018
Posts: 12
If an obvious break like what's in the picture is found I would surmise someone got tired of messing with the airlines and crimped the line. Your back airbags may have a hidden Schrader valve somewhere.
~Pat~ is offline   Reply With Quote
Old 04-16-2019, 07:07 PM   #13
Bus Nut
 
johnbloem1974's Avatar
 
Join Date: Jul 2015
Location: Montana/Texas
Posts: 549
Year: 1998
Coachwork: Crown by Carpenter
Chassis: International 3800
Engine: DT 466e/MT 643!
Rated Cap: 16
That break where the black hose is does not hold any air. It is simply the flexible piece to hold the actuator arms. You may not actually have a leak. It could be just that the arms are not working properly. Replace that piece to get the arms li ed up properly and you may be in business!

John

Edit: Derp! Did not take the time to read the previous posts... sorry for repeating....
johnbloem1974 is offline   Reply With Quote
Old 04-16-2019, 07:12 PM   #14
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 1,948
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
Quote:
Originally Posted by ~Pat~ View Post
If an obvious break like what's in the picture is found I would surmise someone got tired of messing with the airlines and crimped the line. Your back airbags may have a hidden Schrader valve somewhere.

Most don't have Schrader valves, the leveling valve does that job. On some aftermarket pickup air bags and air shocks, that's another matter.



Quote:
Originally Posted by johnbloem1974 View Post
That break where the black hose is does not hold any air. It is simply the flexible piece to hold the actuator arms. You may not actually have a leak. It could be just that the arms are not working properly. Replace that piece to get the arms lined up properly and you may be in business!

John

John's got it right, the rubber tubing on the linkage does not carry any air pressure, it's simply a cheap way to attach (and allow for adjustment of) the rods. And yes, it probably came from the factory this way.
Brad_SwiftFur is offline   Reply With Quote
Old 04-16-2019, 11:42 PM   #15
Mini-Skoolie
 
Join Date: Sep 2016
Location: TEXAS
Posts: 62
Year: 1999
Chassis: MVP RE
Engine: 5.9 Cummins
Just from a review of my pictures, it appears that one of the air bags might have a small hole in it. I didn't see that when I was under there. I'll get a closer look when I get time and its not storming here.
budbud7 is offline   Reply With Quote
Old 04-17-2019, 12:51 AM   #16
Bus Geek
 
Join Date: Sep 2015
Posts: 2,702
Year: 2002
Coachwork: Thomas Built Bus
Chassis: Freightliner FS65
Engine: Caterpillar 3126E Diesel
Rated Cap: 71 Passenger- 30,000 lbs.
Quote:
Originally Posted by budbud7 View Post
Just from a review of my pictures, it appears that one of the air bags might have a small hole in it. I didn't see that when I was under there. I'll get a closer look when I get time and its not storming here.

In the pictures, your air bags do not look deflated. Do they flex back when you touch them?
Native is offline   Reply With Quote
Old 04-17-2019, 05:49 PM   #17
Mini-Skoolie
 
Join Date: Sep 2016
Location: TEXAS
Posts: 62
Year: 1999
Chassis: MVP RE
Engine: 5.9 Cummins
Quote:
Originally Posted by Native View Post
In the pictures, your air bags do not look deflated. Do they flex back when you touch them?
Yes, at least the one that I touched. I will check on parts tomorrow for price and availability. Then, when I get the time, I will attempt to repair it. Most likely someone will have to instruct me in the proper installation and adjustment.
budbud7 is offline   Reply With Quote
Old 04-18-2019, 12:58 AM   #18
Bus Geek
 
Join Date: Sep 2015
Posts: 2,702
Year: 2002
Coachwork: Thomas Built Bus
Chassis: Freightliner FS65
Engine: Caterpillar 3126E Diesel
Rated Cap: 71 Passenger- 30,000 lbs.
Quote:
Originally Posted by budbud7 View Post
Yes, at least the one that I touched. I will check on parts tomorrow for price and availability. Then, when I get the time, I will attempt to repair it. Most likely someone will have to instruct me in the proper installation and adjustment.

If it presses back it probably has air in it. That would mean your system is at least partially fuctional. Your pictures really point to the rubber tube as the problem, or at least one of them.


What are the parts for which you looking to get prices and availability?
Native is offline   Reply With Quote
Old 04-18-2019, 09:40 PM   #19
Mini-Skoolie
 
Join Date: Sep 2016
Location: TEXAS
Posts: 62
Year: 1999
Chassis: MVP RE
Engine: 5.9 Cummins
Got a chance to ck on part prices today. $116 for the valve kit and $175 per air bag. I will get back under there for a closer look at things before I start ordering parts. I might be able to replace the broken hoses. I also need to know how it works in order to adjust the linkage.
budbud7 is offline   Reply With Quote
Old 04-20-2019, 04:35 PM   #20
Skoolie
 
Join Date: May 2015
Posts: 180
That photo!!! Bwahahaha Suspension, brakes and tires are life savers- you screw something like that up, get in an accident and you will go
To jail. The reason commercial trucks are highly inspected is to prevent accidents from failed parts etc. take your bus to a truck mech ic and have them go through it and have them go through the DOT inspection and FIX anything not within specs. That is the responsible thing to do.
Cheers
Commercial driver since 1978
Dirtdoctor 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 01:56 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×