2002 Winnie Journey LD air fault
Seems as if I have a teeny problem with my air system (Freightliner chassis). The last two outings, I have noticed that while driving, the air gauges are slowly dropping to 105-110# then getting pumped back up to 120-125#, then slowly dropping, ad infinitum. I also noticed that a quick rest stop break of a few minutes results in a quick drop in air pressure to the 90-100# range. Once the engine/compressor fires up, all is normal.
Initially I suspected leaking air bags but the suspension stays loaded with air. Eventually it will come down but the problem is clearly not the air bags, particularly since the front and rear air pressures rise and fall in unison. Plus after shutting down for a period of time, there is still LOTS of air pressure released when I pull the lanyards.
It seems to me that there must be a leak in the lines between the compressor and bags. Shutting the engine off and ducking underneath the chassis to try and hear where the leakage is coming from is not working out well. I can't hear any escaping air but it HAS to go somewhere.
Does anyone have any clues where I can look to try and find the source of the lost air? Not making any headway on my own. I don't have a lot of experience with truck air systems, other than making minor repairs such as replacing air horn lines/cannister, etc.
I have been advised to change the air dryer filter and desiccant and have purchasedthe kit and will be doing so but unsure if this will solve the problem.
I have also been told that it a may be a check valve leaking air back into the compressor tank but I am unsure where that would be located.
Many thanks to anyone who can help or provide insight.