sambar Report post Posted November 25, 2014 We have a 43' 2007 Allegro Bus which has recently started emitting an extremely loud and piercing noise during the initial phase of auto leveling. It sounds very similar to the screeching when stretching the mouthpiece of a balloon - only 1000 times louder. HWH as advised us that it is not part of the Hydraulic System. The local Freightliner dealer has offered little help. Has anyone had this problem or can anyone offer help or advice as to what we should do to eliminate this noise. Sambar Ladson, SC Share this post Link to post Share on other sites
wolfe10 Report post Posted November 25, 2014 Sambar, Welcome the FMCA Forum. Sure sounds like your air suspension exhausting it air-- normally the first step in leveling a coach with air suspension. Kind of hard to believe anyone familiar with air suspensions can not duplicate the noise and identify its source. Have you called your chassis maker? Tiffin? Share this post Link to post Share on other sites
dickandlois Report post Posted November 25, 2014 Sambar, Welcome to the FMCA Forum! By chance was the coach parked for an extended period of of time before you noticed the noise? Might have a mud dobber building a nest in the air exhaust vent. Might be the seal on the air exhaust valve that is not currently seated properly and vibrates as it exhausts air. Have you had the air drier filters replaced or do you get an increase in water spray when you manually operate the air tank drains on the Primary and or Secondary air tanks? Rich. Share this post Link to post Share on other sites
hermanmullins Report post Posted November 25, 2014 Sambar, Does it make the same noise when you dump your air? If so then dirt dobbers might be causing a restriction. It wasn't said but do you have air leveling or jacks? Does the noise continue the entire time you are trying to level or just when you begin? And when all else fails, like Brett said call Tiffin. Happy Thanksgiving, Herman Share this post Link to post Share on other sites
sambar Report post Posted November 26, 2014 Thanks for all the input. As it turns out (after reading the manual once again in sloooow motion), I realized I was inadvertently short-circuiting the jack retraction cycle. I mistakenly thought I could terminate the retraction cycle when the green travel light illuminated. Evidently, this action prevented all of the air to be exhausted from the suspension, which upon reactivation of the leveling, forced trapped air to escape prior to jack deployment --- hence causing the very loud screeching noise. The owner's manual for the auto leveling system infers one can travel once the green travel light comes on. While this may be true, the subsequent leveling which follows will result in the screeching of escaping air prior to the jacks deploying. I am 99 % sure this is correct, but plan to verify tomorrow. Will confirm yea or nay later. Once again, thank's for all the replys. SamBar 2007 Allegro Bus 42QRP Share this post Link to post Share on other sites
