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.

My Bus 121.jpg
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.

My Bus 124.jpg
The ends on the brass one looks like they just thread off, havn't tried it yet.

My Bus 125.jpg
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.
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.
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!
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.

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?

[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.