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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Scott & Heather on November 05, 2014, 10:01:24 AM

Title: How do I adjust belt air tensioner tension
Post by: Scott & Heather on November 05, 2014, 10:01:24 AM
I am working to get the belt tightened just a little and have greased all fittings as well as made sure the piston and hinges all moved. Doesn't appear to be an air leak but I have no easy way of checking the pressure since the valve isn't a schrader valve. Do I turn the nut on the regulator and which way do I turn it to increase the air pressure?


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Title: Re: Re: How do I adjust belt air tensioner tension
Post by: Seangie on November 05, 2014, 02:24:31 PM
Scott -

I think...if I remember correctly you turn it counterclockwise to decrease and clockwise to increase.  Best way to check is air up the bus and right before it kicks out turn off the bus.  Then turn the screw counterclockwise until the air kicks out and that will be a decrease in air.  Put a mark on the screw with a Sharpie so you can see how much you turned it.

-Sean

Wandering the country in a 1984 Eagle 10S. 
www.herdofturtles.org (http://www.herdofturtles.org)
Title: Re: How do I adjust belt air tensioner tension
Post by: bevans6 on November 05, 2014, 02:51:26 PM
Ditto on the clockwise to increase.  I carry a tire pressure gauge with 1/4" pipe thread fittings on the hose, I took it apart and screwed it in to where the odd test valve is, and set mine to around 28 psi in a truck stop one afternoon.

Brian
Title: Re: How do I adjust belt air tensioner tension
Post by: Boomer on November 05, 2014, 09:27:40 PM
Why not go to the hardware store and buy a simple turn buckle and replace the air tensioner.  Let's face it motorhomers don't put on enough miles to regularly have to change belts which is what the air tensioner is for, quick belt replacement.  No air tensioner =
no leaky cylinders and regulators as well as no thrown belts when the rpm comes up before the tensioner kicks in.  Same applies to the a/c belt tensioner if one has coach a/c.  JMO
Title: How do I adjust belt air tensioner tension
Post by: Scott & Heather on November 06, 2014, 02:37:42 AM
Sean and Brian thank you! Smart bus people make me happy. Boomer, tell me more....I googled turnbuckle and can kinda visualize the concept but in actual practice don't understand how you installed it. Did you just remove the air cylinder and mount it in that location? I hate the air cylinder system personally for a few reasons so I'd totally be game for a turn buckle system. Can you post pics of your install?


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Title: Re: How do I adjust belt air tensioner tension
Post by: wg4t50 on November 06, 2014, 02:40:15 AM
Boomer has a great point, but on my MC7, each belt air cylinder has a specific air pressure setting for the regulator adjustment, just need a air gauge, very simple.
Dave M
Title: Re: How do I adjust belt air tensioner tension
Post by: Scott & Heather on November 06, 2014, 02:41:53 AM
Dave you're up early...or late...


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Title: Re: How do I adjust belt air tensioner tension
Post by: Debo on November 06, 2014, 06:04:05 AM
I know the test/fill port on my MC9 for my air cylinders is a big Schrader-valve-flared-fitting looking thing - almost like an HVAC port. Does anyone have a good handle on the sizes, or have you made some sort of adapter? Sounds like a couple of you might have.

I was thinking it would be nice to have an adapter to go from that port to a regular car tire Schrader valve so you could just use a tire gauge on it. Something like this: http://www.toolsource.com/r410a-adapter-p-104284.html (http://www.toolsource.com/r410a-adapter-p-104284.html)

I may be off on the sizes since I'm not sure what they are...

Title: Re: How do I adjust belt air tensioner tension
Post by: Boomer on November 06, 2014, 08:39:18 AM
I don't have a pic Scott, have not owned MCI's for years.  Yes, the turnbuckle just replaces the air cylinder and you cap the air supply.  Might take a few minutes more to change a belt but a small price to pay.  Good hardware supply or somewhere like McMaster Karr.
Title: Re: How do I adjust belt air tensioner tension
Post by: lvmci on November 06, 2014, 09:39:28 AM
Hi Scott, like Boomer, I like simpler best, but In the desert south west I think there is a place for tension belt adjusters, from winter to summer, there is around a 100 degree temp change, and our buses are used in the dead of winter and dead of summer too! Lvmci...
Title: Re: How do I adjust belt air tensioner tension
Post by: Scott & Heather on November 06, 2014, 04:33:57 PM
Well, I think I can make a turn buckle work. But I also know I should check the tension often just to be sure I'm keeping up with the temp changes and belt stretching/contracting. An open end wrench to twist it should do the trick. Probably will need a nut to keep it from twisting on its own.


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Title: Re: How do I adjust belt air tensioner tension
Post by: luvrbus on November 06, 2014, 06:38:31 PM
Good belts don't stretch or contract,the older Eagles have long belts with just a manual adjustment idler and you never need to adjust those for years fwiw
Title: Re: How do I adjust belt air tensioner tension
Post by: Scott & Heather on November 06, 2014, 07:43:53 PM
Well, that bodes well for me converting it to a turnbuckle system


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Title: Re: How do I adjust belt air tensioner tension
Post by: Boomer on November 06, 2014, 08:17:03 PM
We operated our buses in temps from 0F to 120F on an annual basis with no ill effects from running manual tensioners.  Those belts are tough anyway.  We very rarely had to replace a belt and I can't remember ever having one break, just inspect regularly for cracking in the groove.  Lots bigger problems to worry about IMO.
Title: Re: How do I adjust belt air tensioner tension
Post by: Scott & Heather on November 07, 2014, 03:54:34 PM
Done. Turnbuckle installed. Installed a nut and lock washer too just to be sure the turnbuckle won't turn accidentally and loosen the belt. This was easy and I'm actually really relieved to get that air cylinder out of there. It just wasn't tightening the belt anymore and I do think this was a part of my overheating issue. Belt is nice and taught now :) thanks so much for the advice


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Title: Re: How do I adjust belt air tensioner tension
Post by: eagle19952 on November 07, 2014, 07:25:51 PM
http://www.c-rproducts.com/downloads/pdfs/guide_vbelt_tensioning.pdf (http://www.c-rproducts.com/downloads/pdfs/guide_vbelt_tensioning.pdf)
Title: Re: How do I adjust belt air tensioner tension
Post by: Scott & Heather on November 08, 2014, 07:58:38 PM
Sheesh. I barely passed calculus my friend. I'm certainly not going to do algebra to determine my belt tension. It's tight, but not too tight. Works for me :)


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Title: Re: How do I adjust belt air tensioner tension
Post by: eagle19952 on November 08, 2014, 08:56:05 PM
Thought you'd get a chuckle...that pdf file is just a reality check...keep it simple ..KISS  :-*

Quote from: Scott Bennett on November 08, 2014, 07:58:38 PM
Sheesh. I barely passed calculus my friend. I'm certainly not going to do algebra to determine my belt tension. It's tight, but not too tight. Works for me :)


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Title: Re: How do I adjust belt air tensioner tension
Post by: luvrbus on November 09, 2014, 04:59:35 AM
Where is Jim of RV Safety or the belt guy one in the same he probably did the calculation formula a sharp guy on belt and hoses, he tried explaining that to me years ago and I had no idea what he was saying  8) so I tighten my belts and went on down the road  
Title: Re: How do I adjust belt air tensioner tension
Post by: Scott & Heather on November 09, 2014, 05:15:32 AM
Don and Cliff....the best way to tighten your belt I hear is...well...spend less money...