CraigandTammy Report post Posted October 3, 2016 When doing my regular visit and start up of my coach yesterday, I started the engine and shortly after it had been running for a few minutes I had a big air blow out. It sounded like it came from under the steering and dash area. As I am new to this, I couldn't figure out what just happened. After further review of my gauges, I found that the air pressure system gauge on the left side was empty. I take it that I had a air line let go. How do you go about searching for the leak/blowout? Is this something I can do or do I need a mechanic to work on it, I cannot move it at this point from its storage position. Share this post Link to post Share on other sites
hermanmullins Report post Posted October 3, 2016 Craig, Welcome to the Forum. If a hose let go you should be able to hear it when the engine is running. If the sound came from around the steering column it may be in or around the brake pedal. This is where I would begin. Good luck. Herman Share this post Link to post Share on other sites
wolfe10 Report post Posted October 3, 2016 Yes, welcome to the FMCA Forum. While you don't say how handy you are, you should easily be able to identify the source of that massive a leak. Then decide if it is something you can tackle or something you need a professional to address. Do NOT even consider driving it until this is fixed. With air brakes, if the leak is on a brake circuit, when air pressure drops, the emergency brake will automatically apply. Share this post Link to post Share on other sites
kaypsmith Report post Posted October 3, 2016 With the engine running, does the air continue to make the hissing sound under the dash? If the leak is sounding there, could be the brake pedal, or the line to or possibly the gauge itself. If you do not hear the hissing sound there, time to go outside and listen for the leak. Could be something as simple as a tank bleed valve gone bad on the air tank itself. If it is a brake chamber diaphragm, you will only hear the leaking air when the brake pedal is depressed, and the gauge should show air pressure on both sides coming back up. It could be an air bag, or the front leveling valve, if an air bag, pressure should be able to build as the pressure for the bags is far less than the build pressure of the compressor. Share this post Link to post Share on other sites
wildebill308 Report post Posted October 3, 2016 One thing not mentioned is the lines to the emergency brake valve on the dash. If the air noise is coming from the dash area I would check it. Bill Share this post Link to post Share on other sites
atom6 Report post Posted October 4, 2016 This just happened to my friend on a 2008 Allegro Bus. Unscrew the center dash cover (instrument panel) holding the speedo, tach , air pressure gauges. On the back of the instrument panel you will see a red & green airline. These airlines are pushed into metal fittings that are screwed into the back of the front & rear air pressure gauges. On my friends coach we only saw a green line as the fitting holding on the red line had self destructed. This caused the red line to act like a high pressure water hose flailing around inside the dash lodging in a far hard to reach corner. You can find it by following the air flow. You will need to purchase a new fitting that screws into the back of the air gauge, then push the hose into the fitting so it will lock. The old fitting will not be reusable. Share this post Link to post Share on other sites
manholt Report post Posted October 4, 2016 atom6, welcome to the Forum. Had a 07 Winnebago Tour. Same thing happened on it, but the fitting was plastic! Then it happened again on a 2011 Allegro Bus! seems to be a reacurring problem Carl Share this post Link to post Share on other sites
wildebill308 Report post Posted October 4, 2016 After re reading this, You said you had one gage showing air pressure and one that didn't. I bet it is the air line to the one not showing any pressure. Let us know what you find. Bill Share this post Link to post Share on other sites
kaypsmith Report post Posted October 4, 2016 Yes I didn't mention the parking brake valve, been years since I owned one with the park brake on the dash. If that is the issue, you will not be able to unlock the parking brake until both lines are reconnected. Share this post Link to post Share on other sites
manholt Report post Posted October 4, 2016 Kay. Where is your park brake located? Carl Share this post Link to post Share on other sites
