Community Forums

FLavionics · 06-06-2019, 12:27 PM

I learned something yesterday that most of you probably already know but I want to share with the group just in case. I read once to make sure your wheels are straight before dumping the air from your air bags or your front tires may hit the fender. My tires actually do extend about 1 inch higher than the fenders when all the air is out. Yesterday I picked up the coach from the repair facility and drove it all the way home and once I got home I realized that I forgot to air up the bags before departing. So why didn't the tires hit the fender on the way home? I had someone slowly move the wheel while I watch the tires and because of the way the tire pivoted it cleared the fenders. I was amazed. So that was lesson one. The reason the coach was at the repair facility is because I had a concern with the airbag, it was making a very loud popping noise when inflating. The shop said it's not a problem and it happens occasionally, they inspected the airbag and found nothing wrong. I was worried that if the airbag did blow that I would not haveost or at least I would lose partial brakes. But wait a minute I just drove home with the air valve in the lower position so my point is if I had a whole or leaking air bag I could move the lever to the lower position and still have normal braking. That was lesson than two. I also realized that I could at least make it to a repair facility with no air in the bags. That was lesson than three.

**Lt Dan** · 06-06-2019, 12:43 PM

Be careful about driving very far with the air bags deflated. It puts the driveshaft out of alignment and can cause excessive wear on the U joints. Some coaches are set up such that once you put then in gear the air bags automatically inflate no matter what position the switch is in. As for the popping bag, that's pretty normal. The rubber gets folded over when the levelers are retracted and pops when the fold inflates. The more extended the air bags are from leveling the more likely they are to pop.

Outbound · 06-06-2019, 12:54 PM

You do not say what the year or type coach you have, I thought most rigs inflate air bag when starting motor, a alarm sounds on mine until required air pressure is reached to travel.

FLavionics · 06-06-2019, 01:17 PM

It's a 2013 Fleetwood Expedition.
I get an alarm until pressure reaches 75psi but air bags can still be set for "lower". I can drive with no air in bags. The benefit here would be if one of the bags had a leak I could push the lever to lower and still have brakes and drive the vehicle to a repair shop

Ivylog · 06-06-2019, 02:20 PM

Most systems automatically inflate above a very slow speed regardless of what you have selected. Are you sure yours did not?

FLavionics · 06-06-2019, 02:34 PM

Quote:

Originally Posted by Ivylog

Most systems automatically inflate above a very slow speed regardless of what you have selected. Are you sure yours did not?

No actuality I am not sure. If that was the case if a leak did accur would it effect the brakes? Or the ability of the compressor to maintain. I figured the valve would be a good way to isolate the system in the case of an air bag leak. But I am also surprised there is no warning that the bags are not inflated.

Skiddy · 06-06-2019, 04:05 PM

Quote:

Originally Posted by FLavionics

No actuality I am not sure. If that was the case if a leak did accur would it effect the brakes? Or the ability of the compressor to maintain. I figured the valve would be a good way to isolate the system in the case of an air bag leak. But I am also surprised there is no warning that the bags are not inflated.

there are normally two tanks, front and rear one for the bags and one for brakes.

twinboat · 06-06-2019, 04:33 PM

Quote:

Originally Posted by FLavionics

No actuality I am not sure. If that was the case if a leak did accur would it effect the brakes? Or the ability of the compressor to maintain. I figured the valve would be a good way to isolate the system in the case of an air bag leak. But I am also surprised there is no warning that the bags are not inflated.

There are 3 tanks in all air brake systems. A wet tank that recieves air from the compressor.

That tank supplies the primary and secondary tanks. Each tank handles either the front or rear brakes.

Your air suspension is probably hooked to the tank that handles the front brakes because they use less air to work.

There is also going to be a protection valve in the air suspension supply. That will cut off the air to the suspension if the pressure drops below 70 PSI, saving the rest for stopping.

If the leak is large enough that the compressor can't keep up ( not likely with suspension plumbing ), once the air drops below 60 psi, alarms start going off, and at 45 PSI the rear brakes come on, stopping you where you in your tracks.