Viewing 15 posts - 1 through 15 (of 38 total)
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    • #2895
      MyPrevost
      Keymaster

      Leak FREE! Yes, my coach is ‘Bubble Tight!’

      Those words are extremely rare in the Prevost community, but my 1994 XL chassis is leak-free in both the braking system and auxiliary air! I know some may doubt this, but it’s true. I’ve tested my coach for five days and haven’t lost a pound of air pressure in either system. This is a first for me during my ownership.

      How did I achieve this? It’s simple—just a little time and patience. I used the renowned ‘Texas Bubbler’ as a leak detector and installed a ‘TexasDrifters Pneumatic Reliability Upgrade.’ This non-Prevost modification included a 12-volt solenoid (purchased from a great supplier for air fittings and accessories) that blocks the air supply to the step well floor slide and ISRI seat when the key is turned off. These two components are known potential leak points. You’ll need to find a switched 12-volt (or 24-volt) location in the Prevost electrical panel to control the solenoid. Getting these two devices leak-free can be challenging, especially for the floor slide, which can leak around the shaft seal if the alignment is not perfect.

      I also found that my auxiliary air compressor was leaking back through the compressor, so I installed a double check valve setup at the outlet to the auxiliary compressor and inlet to the air tank. After making these modifications and repairing a few minor leaks, I achieved 100% leak-free status.

      A sidebar comment: I believe any modification to the Prevost suspension system requires careful consideration. I would only make such modifications in an emergency as a temporary fix. Prevost’s design engineers develop their systems for durability and safety, so I prefer a hands-off approach to suspension modifications. Their systems are great and long-lasting!

      Many POG members may recall my comments at the Austin Rally about ‘MANAGING’ my air system leaks. This means I keep my leaks to a tolerable amount and then find and correct them. The only time my coach is truly leak-free is when it’s sitting in my bus barn. Once I take it out for a spin, all bets are off. But I’m bragging now while it lasts. Once your coach is tightened up, it should stay that way unless there’s a component failure. The last time I did this level of leak detection was three years ago, and my aux air compressor was running twice a day, so it was time for a check-up.

      I call my coach ‘the other woman’ because she’s complicated and definitely high maintenance. But when all systems are ‘fine-tuned’ and she’s airtight, she’s … well, she’s ‘the other woman.’

      I’m happy!

      Hector

      #2897
      MyPrevost
      Keymaster

      Hector,

      That is GREAT! I’ve often wondered if the step slide was an issue. It sounds like you’ve really got this whole air leak thing figured out!!!

      #2898
      MyPrevost
      Keymaster

      Good going, Hector. It’s great to see a CC guy holding his own among all those Buddy Brand buses.

      And may I say, you’re truly an asset to the POG membership. Your efforts, experience, and attention to detail are greatly appreciated.

      Being leak-free is definitely worth bragging about!

      #2899
      MyPrevost
      Keymaster

      Congratulations, Hector!

      Achieving ‘leak-free’ status is a tremendous accomplishment, and you have every right to brag about it. I consider my bus ‘leak-free enough’ when the aux compressor cycles only once or twice a day, but you’ve far surpassed my goals.

      Isolating the step well cover and seat sounds like great advice—I’ll have to check that out.

      Job well done!

      #2900
      MyPrevost
      Keymaster

      You and your coach are literally “FLOATING ON AIR”. Way to go Hector! Keep that P/N handy, because I think that may be one of my trouble areas.

      #2901
      MyPrevost
      Keymaster

      Hector CONGRATS but we all know it is only temporary.

      #2902
      MyPrevost
      Keymaster

      My hat is off to you, Hector. You’re truly a man on a mission to the leak-free zone. Post the message under your name: ‘Air Leak Free 12-07-2011.’

      You’ve definitely earned bragging rights!

      #2903
      MyPrevost
      Keymaster

      Jealous of the other woman. I am JEALOUS. Congratulations, I know that has to be a terrific feeling. I am afraid I will never know that feeling.

      #2904
      MyPrevost
      Keymaster

      Mine’s next right Hector???
      Good job !!
      Wow !!

      #2905
      MyPrevost
      Keymaster

      Great job, Hector! Isolating the step well slide is a smart move. I took a different route and decided to fix the leaking cylinder myself, but I won’t be doing that again—I’m still sore in places I forgot about.

      #2906
      MyPrevost
      Keymaster

      Great job Hector! Isolating the step well slide is a good move, I just took the other route and decided to fix the leaking cylinder, but I won’t do it again, I’m still sore in places I forgot about.

      Must be catching because you are still a pain in my ass.

      #2907
      MyPrevost
      Keymaster

      Hi Hector,

      I still need to return the tool that somehow ended up on my coach when you helped me. I lost your mailing address, so could you email it to me? I’ll get the tool back to you right away.

      Congrats on the ‘leak-free’ coach—though I’m not surprised, as you’ve clearly got it figured out.

      Thanks!

      #2908
      MyPrevost
      Keymaster

      Good work, Hector. After recently replacing all the brake chambers, brake lines, airbags, and Norgren valves, I’m still dealing with a serious lean. I carefully checked each fitting and component after the job but evidently didn’t get the system air-tight. Since it’s no worse than when I started, I’ll isolate the slide and seat after rechecking the entire system with Tom’s electronic ears. What a simple and obvious fix for common leak sources. Thanks for sharing!

      #2909
      MyPrevost
      Keymaster

      Brian,

      From your post, it could be interpreted that aux system leaks might be contributing to the lean.

      Given the number of relatively new owners, I think it’s worth reiterating:

      IF THE BUS AUXILIARY AIR SYSTEM PRESSURE DROPS TO ZERO, THE BUS SHOULD NOT LEAN OR SETTLE DOWN AS LONG AS THE KEY IS OFF AND ANY AUTOMATIC LEVELING SYSTEM THAT IS ACTIVE WITH THE KEY OFF IS DISABLED. This applies to any coach built after 1994 or 1995 that does not release suspension air if the pressure drops below about 35 PSI.

      Once a coach is leveled and the key is turned off, the air in the air bags is ‘locked in’ by the five-port Norgren valves, which block air from entering or leaving their respective air bags. If a coach leans or drops, there is a leak either through the five-port Norgren valve related to the specific position (left rear, right rear, or front) or in the air bags or fittings associated with that position. The rear suspensions (left and right) have an additional valve—a three-port Norgren—between the tag axle air bags and the drive axle air bags, which could also leak to the atmosphere.

      #2910
      MyPrevost
      Keymaster

      See, Jon called me a pain in the ass, but to really experience that function, all you have to do is ride in a vehicle with him as his cassette tape booms out “the best of the Lennon sisters.”

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