Master Caution

[jello_jeep]

Well, trying to be a good owner, and knowing I was fixin to travel thousands of miles to Pahrumph,,, I thought it prudent to get my bus serviced.

I took it to PVML, and they did a level 3 service, air service, gen service and replaced an air spring. They were a bit late getting it done, and I had another appointment at Marathon Beaumont, and talked PVML into taking it there.

Marathon was trying to help me chase down a gray tank odor, and I ended up telling them to pull the tank and inspect for Kraks and whatnot, as well as a few other housekeeping items that were converter related.

I feel most patriotic for having made a considerable donation to boost the economy after those two bills! But anyhoo

I am driving home from Marathon, and after a bit it seems as if I have no power, not going over 45 or so. I am looking in the mirrors to see if I lost a tire or whatever but it all looks OK.

After a bit I scan the instruments, and see I have a CHECK light and a STOP light on, and the Pro-Driver says I have a high coolant temp of 221. So I found the nearest place I could stop with some hope of not getting rear ended, but still in traffic and pulled over.

I knew that part of the service was changing the coolant, so I was already suspecting chenanigans in that regard.

I called PVML and talked to a service guy, who told me to check the fluid window in the coolant reserve tank.

I checked it and it looked ok, but being the trained observer I am, I noticed the fan not turning (strange if its running hot eh) ?

It had slipped the belt! So I shut down, let the air out of the belt tensioners and fired back up. All was then fine.

FWIW I always air up with my compressor before lighting off to make sure I don't throw one when starting. So a big mystery as to how it came off.

Moral of the story is, if you feel like you are losing power, the DDEC can and will de-rate your horsepower and if its severe enough, shut you down. So keep an eyeball peeled on the cautions & gauges.

The End

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453

[Ray Davis]

Wow, glad to hear that it was no more serious than it turned out.

So, how was your service out at Marathon? Did they do a good job?

Ray

[jello_jeep]

Well, they are a bit disorganized, but I don't yet know how good of a job they did, I will make comment after maybe checking it out at Pechanga this weekend... Or somewhere :)

[truk4u]

Jeep,

Good move! Check the pressure at the tensioner valve, I think it needs to be about 50 psi. I'm like you, I never start the bus without aux air just for the reason you experienced.;)

[Jon Wehrenberg]

Maybe I am just lucky. I start the bus on occasion with zero air in it.

After I have been working on it and have drained the air tanks I don't bother airing it up. I just start it up and let it idle.

So far, both buses have never thrown a belt.

[garyde]

Hi Warren, is it possible the mechanics started the bus and threw the belt before you picked it up? If not, maybe a leak.

[lloyd&pamela]

to help us that are still trying to understand all the terminology, what do you mean by airing up the belt tensioner?

I just start the bus and do not move it until the air tanks are full and the bags make their psssss sound. Is that correct or is there something else I should be checking. Or is this only a Series 60 issue? Thanks

[Jon Wehrenberg]

On earlier model coaches equipped with OTR and all later model coaches the various belts were held in tension with auxiliary air pressure.

On some early coaches I believe an air tensioner was an option. The early belt tensioners were brass air cylinders and later ones were donut type bellows. Until aux air pressure built up all buses with pneumatic tensioners had loose belts.

[lloyd&pamela]

Thanks Jon. I will deal with that on the next bus. See you soon. Looks like it is going to be a great day in Sevierville.

[jello_jeep]

I had thought the same thing Gary, I think they moved it around the lot to the shop and fired off without any air in the tensioners.

Another lesson learned.. When picking it up, check those belts!

[Joe Cannarozzi]

I thought that there was an internal spring to keep sufficient tension until air comes up. We have never thrown a belt and those things weren't even working for the ride from Nashville to Chi. the day I picked it up.

[truk4u]

No spring on the series 60 setup Joe.

[BUSTER]

All,

When leaving Kerrville last year, I could not get up the hills to the East. My temp guage went high. I pulled off and found the belt to the fan off.....Now...I run my air compressor for about 2 minutes before I try to start and it tightens up the belts...BEFORE..I start...that is now part of my start up routine...I have a Country Coach and have an air compressor swith above the driver...

[Jon Wehrenberg]

Joe, You have OTR and your coach probably has the brass belt tensioner cylinders. Those were made to provide a degree of spring tension even when the aux air had zero pressure. Your air valve up over the center of the door opening applies air pressure to maintain tension, but when you turn the valve to release belt tension, it applies pressure to retract the cylinder so you do not have to fight against that spring to change a belt. I actually like that system much better than the present one.

The newer coaches with the little donut sized bellows allow the belts to go completely slack until aux air pressure is built up.

[Ray Davis]

My 93 coach with 8V92 had only manual screw-type adjusters. No air whatsoever.

[Jon Wehrenberg]

Ray,

If you did not have OTR on your coach it is highly probable you did not have the air belt tensioners. I cannot speak about all the coaches out there today with the small bellows, but on my coach with OTR all belts use the bellows tensioners with the exception of the spring tensioner on the engine (which in some cases is a jack screw).