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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: christopher on April 15, 2008, 07:29:54 PM

Title: air pressure in the tires
Post by: christopher on April 15, 2008, 07:29:54 PM
what is everyone runing? i was told 110 in the front and 100 in the back. they are 12r22.5
thanx
chris mci5c 26000 lbs
Title: Re: air pressure in the tires
Post by: belfert on April 15, 2008, 07:33:12 PM
You really should weigh the bus on a scale that can give axle weights.  After that, find the air pressure chart for your particular tires and set the pressure according to weight.  Your tire dealer should be able to help if you can't find the chart online.

110 is probably high unless you have a really heavy conversion.
Title: Re: air pressure in the tires
Post by: TomC on April 15, 2008, 09:24:08 PM
Most of us do not carry close to the weight ratings of the tires.  For instance- I have 11R-24.5 16 ply tires that on the sidewall say 120 psi maximum pressure.  If I ran that, the bus would ride like a forklift.  I weighed my bus fully loaded with my wife and I in with all gear.  My front axle was 10,500lbs and my rear axle was 20,500lbs.  On the Michelin inflation table that works out to be 85lbs.  For safety sake, I run 90psi all the way around and the bus rides great!  Get your bus axle weighed.  If you don't have the load tables, post the weights here and I can look them up at work.  Good Luck, TomC
Title: Re: air pressure in the tires
Post by: Barn Owl on April 15, 2008, 10:09:13 PM
My bus weighs 10,000lbs front and 16,000lbs rear. I run 90lbs all around. I have Goodyear tires. Below is a link to Goodyear's tire inflation recommendations.

http://www.goodyear.com/truck/pdf/edb_loads.pdf
Title: Re: air pressure in the tires
Post by: JohnEd on April 16, 2008, 12:04:14 AM
I run what is recommended by the mfr for the weight I carry....for starters.  After a long run down the interstate I get out my trusty "no contact" IR temp gun.  The middle and both outside edges should be the same temp if the tire is properly inflated.  High center is too much air.  High outside edges is too little air.  One edge high is camber or tow-in/out not properly set.  For the sake of MPG err on the side of too much air.  If you are selling the bus...go light.  Alignment problems are usually detected by a thrashed tire but checking the tire temp will flag the problem almost immediately and certainly prior to tire damage.

FWIW,

John
Title: Re: air pressure in the tires
Post by: GM0406 on April 16, 2008, 06:38:35 AM
Wow,  what a revelation!!!   :o  Amazing man's abilites and the complexity of this life.  I use one of these temp. guns all the time, but did not think of this application.  Very interesting and a testimony of the abilities and knowledge that is evident in this group.  Bill Thomas
Title: Re: air pressure in the tires
Post by: HB of CJ on April 16, 2008, 11:52:40 AM
Yeah, same answer here.  Go find out the minimum pressures per the actual weight carried and go from there.  Softer ride usually.  Also good to know exactly what your Bus Conversion weighs on all four, (4) or six (6) corners.  :) :) :)