Question How long will your air brake tank hold its air pressure when not running?

[Neal]

For the DP owners with air brakes, when the engine is not running, how long does it take before your air brake tank depletes its air pressure? I'm not sure if they are designed to hold pressure or designed to deplete the pressure, i.e. maybe it's not supposed to maintain pressure when the engine is not running. Mine works fine while running but I'm surprised in 24 hours that it's essentially depleted and when airing up it has to go from about 50 to 130 for the popoff.

What do you see with yours?

 

[turbopilot]

My 2018 New Aire will hold pressure for weeks when parked in doors and totally inactive. Meaning nobody goes into the coach. When we are living in the coach just stopped for the night pressure will often go down in 12 to 24 hours. When the coach is left alone outside with full tanks and bags full I have seen pressure deplete in a few days without anyone in the coach if the coach is exposed to strong winds rocking the coach. So it appears any activity moving the coach will accelerate tank and air bag depletion.

 

[Old-RV'er]

All the air lines according to one service center are push on fittings, air tight? Mine will lose all it's air in a 3-4 days to a week, and takes about 2-3 minutes to pump up past the buzzer warning stopping, about 60PSI, which is DOT rule for air brakes systems. Below 60PSI the air brakes will engage and not release, a built in safety feature. Big honking spring in the actuators which is held open by Air pressure. I had MH with Hydraulic brakes, there are good and bad sides to both systems. I prefer the airbrakes based system, stronger and larger surface braking area, so coach will slow down and stop faster. Now I need to remember to pull the handles on the tanks and get the water out. Friend said he used to do it quarterly, and never had any water come out. Don't remember the rule in the manual, most likely monthly.

 

[MemoriesByTheMile]

We have air brakes but are not a class A DP. It has been 2 or 3 weeks since the engine ran last and we still have 60psi in both primary and secondary tanks (and I bumped the brakes once on accident when I was moving the steering wheel).
We live in it full time so it has regular motion but our air bags are not actively having to adjust to carry any dynamic loads due to the hydraulic levelers carrying a bunch of the weight.

 

[VernV]

It is very system or vehicle dependent and varies a lot. There are many places for small leaks to occur and most of them are undetectable. Our 4369 will go a couple of weeks if nothing causes the height control valves to operate. As long as the compressor can keep up going down the highway there are really no issues. The air brakes are actually spring applied and it takes air to release them so the braking system is fail safe.
Vern