Low Rear Air

[dperkinstx]

When I start my 2007 Fleetwoodwood Revolution LE, I get a Low Rear Air alarm. After running for maybe a minute, the pressure comes up and the alarm goes off. All is good for the rest of the day. Where might my leak be?

[jacwjames]

Could be anywhere.

Best thing to do is build yourself a set of 6 ramps to drive up on for safety. I made mine out of 2X10's cut into 48,42,36,30" lengths screwed together. I added a block at the end of four of them for the rear tires.


Then get a spray bottle of soapy water and start spraying all the fittings on the tank and lines. Spray all the fittings on anything the air lines are connected to.

I went through mine in 2021 and found all four of my Pressure Protection Valves (PPV's) were leaking. So I replaced all of them along with any other part the could fail over time. Not much money, just took time. If you can afford to wait ordering parts off the internet could save you some money.

Now my air stays up for weeks.

[Iceclimber]

Also may be the valve that equalizes the tanks. By the way it's ok for air systems to lose some air overnight but this seems pretty specific and it's alarming overnight that is a bit. If you look at the gauges you may note red or green dropping which gives you a hint as to which system. Also your coach is of a certain age so you may consider changing the whole air dryer assembly. Around $100 for a no label off amazon. The name brand kind are ridiculous expensive and the same thing. If you are not the stalwart type to build the ramp system above, truck tire places will work on your air brakes. Just call around.

[Lt Dan]

How long does the coach sit before the air pressure drops? It's perfectly normal for air to bleed down over time.

[Gary RVRoamer]

Many coaches dump the suspension air when leveling and it is normal to hear the low-pressure warning at start-up, until the compressor rebuilds air pressure. I would expect an American Revolution to do that.


If you haven't dumped the suspension air, it's simply a matter of a leak (may be multiple). Any or all of the items mentioned here already. At age 16, it's hardly surprising that some hoses, connections or even an airbag have small leaks. Get out the soapy spray and start hunting. Or drive it to a truck or diesel RV service center and let them do it for you. It's a common repair.

[Tha_Rooster]

Originally Posted by dperkinstx

When I start my 2007 Fleetwoodwood Revolution LE, I get a Low Rear Air alarm. After running for maybe a minute, the pressure comes up and the alarm goes off. All is good for the rest of the day. Where might my leak be?

How long does it sit to get a low air?
If air bags are original you have a good chance they are cracked and just waiting to leave you stranded.

[Iceclimber]

Originally Posted by Gary RVRoamer

Many coaches dump the suspension air when leveling and it is normal to hear the low-pressure warning at start-up, until the compressor rebuilds air pressure. I would expect an American Revolution to do that.


If you haven't dumped the suspension air, it's simply a matter of a leak (may be multiple). Any or all of the items mentioned here already. At age 16, it's hardly surprising that some hoses, connections or even an airbag have small leaks. Get out the soapy spray and start hunting. Or drive it to a truck or diesel RV service center and let them do it for you. It's a common repair.

I still need to do a front to back inspection on mine as you recommend, takes me 2-3 days to lose air but after my recent misadventures I learned how these things cascade into a real problem. I do advise changing the dryer assembly not just the can if it's never been done.

[Ray,IN]

Through the years I've determined that locating and stopping all air leaks is an exercise in futility. An air leak can be hidden in the compressed air plumbing system, and thus never found unless every check valve is replaced in the system.
I have a small air leak in the rear air spring system,but it is not large enough to be of concern.
I have s compressed air system drawing if it might be helpful.

[Gary RVRoamer]

The air dryer cartridge ought to be changed every 3-4 years as a routine thing. Sort of depends on the hours the air system is operating, but few RVs get a lot of engine hours so years is often a better measure.