Viewing 15 posts - 1 through 15 (of 16 total)
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    • #6749
      MyPrevost
      Keymaster

      Well, trying to be a responsible owner before my trip to Pahrump, I thought it best to get my bus serviced.

      I took it to PVML for a level 3 service, air service, generator service, and they replaced an air spring. They were a bit delayed, and since I had an appointment at Marathon Beaumont, I convinced PVML to take it there.

      Marathon was helping me track down a gray tank odor, and I eventually told them to pull the tank to inspect for cracks and a few other related housekeeping items.

      I certainly made a generous contribution to the economy after those two bills! Anyway, as I was driving home from Marathon, I noticed I couldn’t go over 45 mph. I checked the mirrors but didn’t see anything wrong.

      After a while, I noticed the CHECK and STOP lights were on, and the Pro-Driver indicated a high coolant temp of 221. I found a place to pull over safely, even with traffic.

      Since part of the service included changing the coolant, I was already suspicious. I called PVML, and a service guy told me to check the coolant reserve tank. It looked fine, but I noticed the fan wasn’t turning—which is odd if it was running hot.

      Turns out the belt had slipped! I shut down, released the air from the belt tensioners, and restarted. Everything was fine after that.

      For what it’s worth, I always air up with my compressor before starting to avoid throwing a belt. So, it’s a mystery how it slipped off.

      The moral of the story is: if you feel like you’re losing power, remember that the DDEC can de-rate your horsepower and might shut you down if it’s serious. Keep an eye on the cautions and gauges!

      The End.

      #6751
      MyPrevost
      Keymaster

      Wow, I’m glad to hear it was nothing more serious!

      How was your service at Marathon? Did they do a good job?

      Ray

      #6752
      MyPrevost
      Keymaster

      They seem a bit disorganized, but I’m not sure how well they performed the service. I’ll share my thoughts after I check it out at Pechanga this weekend or somewhere else!

      #6753
      MyPrevost
      Keymaster

      Jeep,

      Great idea! Check the pressure at the tensioner valve; it should be around 50 psi. Like you, I always start the bus with aux air to avoid the issue you just had.

      Tom Chilcote
      Trans-Specialists RV Batteries
      tom@transpspecialists.net

      #6754
      MyPrevost
      Keymaster

      Maybe I’m just lucky, but I sometimes start the bus with zero air in it. After working on it and draining the air tanks, I don’t bother airing it up—I just start it and let it idle. So far, neither bus has thrown a belt!

      #6755
      MyPrevost
      Keymaster

      Hi Warren,

      Is it possible the mechanics started the bus and threw the belt before you picked it up? If not, there might be a leak somewhere.

      #6756
      MyPrevost
      Keymaster

      To help those of us still learning the terminology, what do you mean by airing up the belt tensioner?

      I usually just start the bus and wait until the air tanks are full and the bags make their “pssss” sound. Is that the right approach, or is there something else I should be checking? Is this specific to the Series 60? Thanks!

      #6757
      MyPrevost
      Keymaster

      On earlier model coaches with OTR and all later models, the various belts were kept in tension using auxiliary air pressure.

      Some early coaches might have had an air tensioner as an option. The early belt tensioners were brass air cylinders, while later ones used donut-type bellows. Until the auxiliary air pressure builds up, all buses with pneumatic tensioners will have loose belts.

      #6758
      MyPrevost
      Keymaster

      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.

      #6759
      MyPrevost
      Keymaster

      I thought the same thing, Gary. They likely moved it around the lot to the shop and started it up without any air in the tensioners.

      Another lesson learned: when picking it up, be sure to check those belts!

      #6760
      MyPrevost
      Keymaster

      I thought there was an internal spring to maintain sufficient tension until the air builds up. We’ve never thrown a belt, and those things weren’t even functioning during the ride from Nashville to Chicago the day I picked it up.

      #6761
      MyPrevost
      Keymaster

      No spring on the series 60 setup Joe.
      Tom Chilcote
      Trans-Specialists RV Batteries
      tom@transpspecialists.net

      #6762
      MyPrevost
      Keymaster

      All,

      When leaving Kerrville last year, I couldn’t make it up the hills to the east, and my temp gauge spiked. I pulled over and found the fan belt had come off. Now, I run my air compressor for about two minutes before starting to tighten the belts—that’s become part of my startup routine. I have a Country Coach with an air compressor switch above the driver.

      #6763
      MyPrevost
      Keymaster

      Joe,

      You have OTR, and your coach likely features brass belt tensioner cylinders. These are designed to maintain some spring tension even when the auxiliary air is at zero pressure. The air valve above the center of the door applies pressure to keep the tension, and when you turn the valve to release it, it retracts the cylinder, so you don’t have to struggle against the spring when changing a belt. I actually prefer that system over the newer ones.

      The newer coaches with small donut-shaped bellows allow the belts to go completely slack until the auxiliary air pressure builds up.

      #6764
      MyPrevost
      Keymaster

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

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