Air leak

[gwj]

Last Friday I parked my DP in front of my house. I left the air ride system inflated. Before I turned the engine off I looked at the pressure gauges, they both read 125 PSI. This afternoon I started the engine, and I noticed the front PSI was 35 psi, and the rear PSI was 125 PSI. I also noticed the air ride system was completely deflated. Where should I start to look for the leak, front brakes, air ride system. I have a 2002 Fleetwood Expedition, with a ISB 300.

[gwj]

Last Friday I parked my DP in front of my house. I left the air ride system inflated. Before I turned the engine off I looked at the pressure gauges, they both read 125 PSI. This afternoon I started the engine, and I noticed the front PSI was 35 psi, and the rear PSI was 125 PSI. I also noticed the air ride system was completely deflated. Where should I start to look for the leak, front brakes, air ride system. I have a 2002 Fleetwood Expedition, with a ISB 300.

[RV Wizard]

If you want to find the leak you will want to start at the compressor and have the system completely aired up. Use a solution of dishwashing detergent and water to make a leak finder in a pump spray bottle. Spray a little soapy water on all fittings and listen out for the sound of air leaking out of the system. It could be anywhere. Good luck and let us know what you find.

[gwj]

Thanks.

[Joe-K]

It's hard to tell from your post how many days that the suspension stayed aired up, but it's not unusual for the suspension to drop after several days.

On our Journey, if I dumped the air suspension when parkig the rig, the air tanks would stay fairly full for quite a while. If leaving the air suspension filled however, depending on conditions, I'd find the tank supplying the suspension low after several days.

The reason for this is that due to coach movement, the system is adding and removing air from the air suspension. Whenever the coach rocks due to someone walking in the coach, or wind rocking the coach the suspension is working.

I used to notice the hissing of air being added to the air bags whenever I stepped on the entrance step going into the coach. As soon as I stepped off the step, the air would bleed back out again. It doesn't take much adding and releasing of air due to coach movement for the air in the air tank to become depleted.

[gwj]

Joe, do you think I should release the air from the air bags, and see how bad the leak is first. I left the air bags inflated for 3 days, and the front tank got down to 35 PSI.

[Gary RVRoamer]

gwj,
That degree of air loss is pretty common and nothing to be much concerned about. But yes, it is leaking air and you can find and fix the leak(s) if you want, using the soap bubble, look and listen technique that Mike [RVWizard] described. There area zillion air line couplings and valves under the coach and it is likely a collection of small leaks, with perhaps one larger one. If you fix enough of them your air pressure will probably stay up for at least a week and perhaps several weeks.

I just had two valves replaced on mine (a dump valve and the brake treadle valve) after the air loss got severe (completely lost all pressure in about two hours) and I still have the sort of small leaks you describe.

[Digital Boy]

RV Wizard is right on. I had a similar problem with my coach in 2005. An RV tech checked my system and noted that I had three leaks: one at the compressor connection; one at the rear ride height valve; and a very small leak at the solonoid that controls the air horns.

The tech tightened the compressor connection (the worse leak of the 3) right then and there. Since I was at an FMCA area rally in MA, I opted to fix the other leaks upon my return to Florida.

Later, the Cummins/Spartan shop in Ocala replaced my cracked rear ride height valve and I have had no measurable leaks since then.

By the way, as a general rule, you should bleed the air tanks (I have 3) every week when traveling or upon arrival at your final destination. I have 3 plastic cables that I pull from the front genrator compartment to drain the tanks.

[georgetown350]

Build the preasure up and apply the brakes and hold. Preasure should drop a few psi and then stop. If it continues to drop preasure then you have a problem.

[georgetown350]

pressure