replacement air springs

[Jon Wehrenberg]

My misunderstanding. A smaller diameter is the reason. These are some points of reference.

The Goodyear number has the nominal diameter following the R. A 1R11 model designation is a nominal 11" diameter. It could be 10.5" or even 11.25"

A 10.5" diameter (actual) has 86 square inches, so to lift 14,000 two air springs need to be pressurized to around 81psi. (81 PSI X 86 Square inches X 2 air springs) will start to lift the front.

An 11" diameter (actual) has 95 square inches so to lift the front it only needs about 74 psi.

These are theoretical and it is likely the effective lifting surface is less than the diameters given above and the diameter in the Goodyear part number probably references the outside diameter of the rubber bellows which expands a little when inflated.

My point however is that as you can see from the above even a small reduction in the diameter has a large effect on the pressure required to lift the bus. Until those buses with problems lifting the front get air springs of sufficient diameter there is nothing short of increasing pressure that will make them lift. Why one bus will lift and another will not depends upon how much weight is to be lifted. If the front axle weight is heavy, more pressure is required to lift.

There are only two concerns when selecting an air spring. Prevost, for some unknown reason has chosen sizes that do not perform as the original air springs have performed. Prevost appears to be concerned about the same things we are, but to less of an extent for bus leveling.

As long as the air springs do not interfere with anything, such as rubbing the tire or any other part of the bus the size is acceptable. That means if you are not satisfied go to a larger air spring as long as the increase in diameter does not rub anywhere. The second, and equally important concern is that the air spring has no less travel than the suspension has.

This site http://stengelbros.3dcartstores.com/...Lobe_c_62.html is as good as any that I have found to research for larger air springs.

[lewpopp]

Joe,


Sorry about your loss. It will leave an empty space in your days and it will take time. As a kid I never had any sorrow for anyone who lost a pet because I never had one until I adopted my daughters when I was 65 or so. When I lost Woody I couldn't replace him for over a year because I didn't want to replace the good times we had. I have a replacement now and he is an important family member.

[rbeecher]

Truk,

I am sending you a PM.

Richard Beecher
02 Marathon XLII 45
96 VOGUE XL 40

[gmcbuffalo]

did we get a solution on this thread?
GregM

[Jon Wehrenberg]

Eric and Debbie had 630260 air bags, replaced them with 630259 and the problem with the front end not raising as it should has been resolved on their bus. They have about 14,000 on theirs.

I'm not sure if we know yet if the Mae Wests (630126) are a larger diameter, and thus can lift more or if they have been directly replaced by the 630259.

[Joe Cannarozzi]

The Mae Wests are for sure a larger diameter but that is meaningless cause ya can't get um no mo.

Now the question is why the 259's aren't raising bluevost's bus the same way the 260's were preforming on Deb and Eriks?

If I had to guess I would say just because bluevost invoice says that they got the 259's that does not mean they actually got those bags, and I ain't jokin.

[gmcbuffalo]

Going back to the raising problem. I tried the other day to raise the front up to put a set of Jon's stands under the it. Could not get the front high enough to put the 14" under it. I raised the tag but no luck. Got out the "air over" raised it up. I was going to check the numbers on the shocks so I could get another set. They are Monroes 630134, on the Monroe website they are listed for Provest XL's drive axles. 630136 are suppost to be on the front. So the question is do the driver axle shocks have less travel than the fronts and tag shocks? Could this be why I could not get the front raise that last 1/2" to put the stands under it? When I rasied it with the jacks I think I got the extra travel from the tires.
GregM

[gmcbuffalo]

Another website list the 630136 for IFS buses. The tag is the same as the drive axle. No info for the front.
GregM

[Joe Cannarozzi]

Greg I have snapped the eyelets off a couple of front shocks over the past few years on our bus. This was before I became as proactive as I have become now but think it probably happened while in level-low trying to get level on a crooked spot.

Looks like we both may have the wrong ones on the front.

The front shocks on an IFS have a threaded stem on the bottom not an eyelet.

[Joe Cannarozzi]

I just had the opportunity to do another suspension replacement it is the second in short order and on 99 and 98 chassis.

Up until now I have not had the opportunity to get anything of this vintage. So now, Ive seen three distinct differences in air delivery: valves, plumbing, hose diameter and fitting configurations.

The 98 and 99 both XL's with a small air tank attached to every bag.

Warrens 95 Did not have this so some where between 98 and 95 this change occurred. Lots of hose diameters and fittings are different. The 95 does have those wonderful non reusable push in type supplying the bags, 1/2 in plastic line.

99/98 has 5/8 and 3/4 plastic supply line going into the bags were it is 1/2 in pipe. All push-in "non-reusable" fittings.

If you are replacing bags you had better have replacements on hand because you will need some. The norgrens are plumbed goofy too. One 5/8 plastic line into a old style compression, good. Then 2 other ports are 1/2 plastic ( 1 elbow 1-T)"non-reusable type into the valve at 3/8 pipe", bad. Finally the valves have 1/4 in female pipe to both the old style and non reusable ends I am adding all those fittings to my tackle box.

The 98/99 has 3 different type hose ends feeding the brake chambers on the rear: 4 with 1 time compressed ends made to length, bad. 2 with reusable ends and 4 plastic good.

Plastic is preferable to rubber but can only be used when there is NO movement between the two ends.

This latest bus got all new brass reusable 2 piece brake hose ends where they did not previously exist and all new rubber hose for the remainder (the steer axle service brake lines and the drive maxi line already had the reusable 2 piece ends) All of the air bag fittings were changed to old style.

All the norgrens ports are 3/8 female pipe and 1/8 female pipe to the ends, for ALL years, Hallelujah

The have changed the ride height valves to these little--------. made them way smaller and cheaper to produce and still charge the same.

IMO the old ones are way more robust. Again the 95 and older have them. They look like they would bolt right in the 98/99 but possibly a fitting change or two. This probably changed with the addition of the air bag tanks between 97/98, guessing.

IMO these push-in fittings work wonderfully when being used for the first time but once the seal is disrupted, such as when you pull the air bag and the fitting is now 8 or 10 yr old, it is a crap shoot if they will seal.

If you replace them and it is with the "old style" with the Ferrell the initial cost is slightly less than push-in and you have a more permanent seal and the next time you have to disassemble it it requires a Ferrell at less than a buck. The drawback is it increases the labor involved on removing valves in some tight spots. The push-ins cost more and have the potential to fail after 1 use but make removal a snap and they look slick. The Liberty guys could clear-coat them too

I got off the train in a small town in Ohio w/o a station only a platform at 4 AM in a snow sleet slop storm. I got the perfect cab driver. If Debbie were with me I'd of had to slow this guy way down or she would have got out. He made 45 mile or so in the same amount of minutes on 2 lane with 6 or 8 in of slop and snow ruts. As long as there is cab drivers like this who needs a lisence! The day brought heavy snow just like a day we would beg for when we were younger, an additional 8 or 10 inches of powder! I enjoyed the day in a heated garage workin on a camper eating like a king. Ain't life grand.