Air Belt Tensioners

[Joe Cannarozzi]

I have 2 different stlyes on this bus and have no idea if they are both original or not or if this is something other folks are seeing on theirs.

The A/C one is brass with threaded ends for getting it apart. The ends on the one for the fan are held on with large c-clips and it is not brass.

Is this normal or has something been changed here? Does anyone else have 2 different belt tension cylinders?

Found a few issues back there this afternoon. I put a new control valve for the belts above the doors and found that the regulator its hooked to to be making bubbles at the flange. Was able to take a 3/8 I think, and tighten up all the flange bolts on it and it stopped leaking. Nice tip Jeep. Found a rotton air line where the feed line to those cylinders T-s off on the motor too.

Will tomorrow be the first morning I find it with the suspension still up????

[Joe Cannarozzi]

Turns out in 86 you got 2 different belt tension cylinders.

1095
I can't get this one apart. I squeese the c-clip and put air to it and can't get the end to even budge.:mad:

1096
The ends on the brass one looks like they just thread off, havn't tried it yet.

1097
The rebuild kits come with no instructions has anyone rebuilt either of these?

[JIM CHALOUPKA]

Joe,
There is the possibility that the snap ring must be completely removed from the assembly. Your simply squeezing it may not allow it to release all around it's diameter in the groove. Even though it goes together with the snapring in the assy., there might be dirt in the clearance area that prevents the ring from positioning into a clearance area. You also might not be using snapring pliers that are stiff enough to completely collapse the ring. You could use a hand held Die Grinder or Dremil type tool and make an exit path on the outer edge of the cylinder to be able to pull the snap ring out after grinding off one of the eyed ends. That would ruin the ring but you probably got a new one in the kit. You could most likely buy all the parts in the kit at a local bearing supplier at a much lower cost.
You didn't say is the cylinder spring loaded?
Can you make the piston travel in and out by reversing air to the ports?
If you can then hold the cylinder in a vise in such a way as not to damage it and with the piston aimed in a safe direction so that when it is ejected no one will be hurt.
Make an air connection to the ports so that you can alternate stroking the cylinder with high pressure shop air to hammer the cap off by the air propelled piston over its full stroke. All the while squeezing the snap ring pliers. If you had more hands it would be easier. :p
Another way would be to screw a slide hammer to the piston and then tap, tap it out while the cylinder is being held in the previous vise setup while relieving the snap ring.:eek:
Or you could drill out a weight as on a slide hammer and place it over the piston and tap against a washer and nut/bolt on the piston end. (don't remember the photo )
This is a poorly designed cylinder, but thats the way it is and you have to suffer it out!
:eek: JIM

[JIM CHALOUPKA]

Joe, How did the cylinder rebuilds go? I'm guessing you finished the job, or did the nice weather take you back to the garden? Would like the follow through on your project.

Also wondering if that leaking new relay finally settled in or did it go back?

Are the air components returnable or are they like many electricals that are nonreturnable?

:) JIM

[Joe Cannarozzi]

You need a special tool to get these apart. They are not user servicable.

[rfoster]

Can someone tell me from their memorry bank what is the correct air pressure for the air belt tensioners on a series 60? Just installed new ones and A/c belt is slipping - I keep increases a couple of notches at a time but don.t want to go overboard.:cool:

Thanks in advance

[Joe Cannarozzi]

Rodger

75lbs for our 86XL.

On ours you also have to adjust the threaded rod and turn buckle that they are attatched to so that you get to the point that the piston that is coming out of the adjuster is petrouding out of the adjuster exactly 1 inch.

I think all the air pressure in the world will not do it unless you first give that piston comming out of the adjuster the correct pre-load.

[truk4u]

40 lbs King.

[Joe Cannarozzi]

One of the 2 belt tensioners that I pictured in a previous post is junk, not rebuildable. A new one is conciderably more than I have to spend right now. Does anyone have one that they have removed and is not using I could purchase? Does anyone know where I might find a used one?:confused:

[Jon Wehrenberg]

Joe, In the interim if you want you could use a threaded rod and the tie rod ends that are on the tensioner.

I think the rod ends are 1/2 - 13 or may be 1/2 - 20. I can't remember, but you can get threaded rod and cut to the approximate length.

The pneumatic tensioners were only provided on bus air equipped buses and those without bus air had belt tensioners as I described above.

[Joe Cannarozzi]

Thats what I have been using and was really looking forward to getting things back to original:( Prevo wants about 600 bucks for a new one.

[Jon Wehrenberg]

Any bus junk yards around that sell stuff like that? I doubt that Prevost builds them, so if they are not available at a junk yard or parts house, then the next step is to find the source Prevost uses.

[Joe Cannarozzi]

Were are these bus bone yards of which you speak?

[dalej]

Let me know if anyone finds a prevost salvage yard, I want to somtime replace my rv style windows in the back of the bus with Le Mirage windows so they match the front. I will need 2 plain and 2 with the sliders.

I think I will have the panels cut local. Since they are glued and then riveted on they will come off looking like I ran over them, I'm guessing.

[JIM CHALOUPKA]

Joe, here is a site for some generic air cylinders that would probably suite your tensioner needs. I don't have the dimensions of your old one but interpolating from the thread on the rod end and guessing the size I do think there is something in the list that will work for you. Hope this helps you. https://reidecom.reidtool.com/xephr/edit/ITEM_GROUP?query=GROUP_PARENT=&query=*GROUP_ID=134511&query=*START_WITH_ID=134511 ("https://reidecom.reidtool.com/xephr/edit/ITEM_GROUP?query=GROUP_PARENT=&query=*GROUP_ID=134511&query=*START_WITH_ID=134511")

[Joe Cannarozzi]

Jim the link doesn't seem to be working can you try again?

[Joe Cannarozzi]

Works now, thanks, this is a fantastic find.

For those of you who are unaware of the Prevost replacement cost for these air belt tensioners, it is over 10 TIMES what these folks are asking.

Jim, also, can you elaborate on your lighting suggestion with the LED light strip, I need the home page for that company.

[JIM CHALOUPKA]

Joe, I edited the original post on the light bar showing the main site, but you can also find it by a Google search of West Mountain Radio. ;)

[Jon Wehrenberg]

Joe, I had these cyclinders on the old coach and if I recall they had an internal spring to keep pressure on the belts if the bus air system was down. Not enough pressure to tighten the belts, but enough to keep them from jumping off when the bus was started and until air pressure built up.

When the knob was turned the cylinders used air pressure to retract against the spring so the belts were completely slack for removal.

That makes the Prevost cylinders a rare version. Due to the length of the push rods however a cheap two way cylinder and an external spring to apply initial tension should not be difficult to fashion.