jacks & air bags

[gator67]

My wife thinks to ask questions that never occur to me... here's one of them.

We are camped in an RV park and I figured, while the tires are cool and I have the time, I'll air them up to the proper pressure. In order to do that, of course, you start the engine, the air bags fill and the coach rises, but the jacks are still down. After I filled the tires, I dumped the air.

Is there any problem with going through the process of airing up and then dumping the air with the jacks down and the coach leveled?

[gator67]

My wife thinks to ask questions that never occur to me... here's one of them.

We are camped in an RV park and I figured, while the tires are cool and I have the time, I'll air them up to the proper pressure. In order to do that, of course, you start the engine, the air bags fill and the coach rises, but the jacks are still down. After I filled the tires, I dumped the air.

Is there any problem with going through the process of airing up and then dumping the air with the jacks down and the coach leveled?

[Tom Viren]

The only problem I can see is since the jacks are taking the major share of the coaches weight, you may get a false reading on the air gague. Once the tires support the entire weight of the rig the pressure in the tires may be greater than you wanted.

[Barbaraok]

Why bother when you are parked? Why not wait until you are getting ready to go somewhere - that's when its important.

[SteveS]

Tom - It depends on where you are parked. If you are on a nice level spot it would be least likely to cause the jacks to shift, but they still can shift when you dump again. There will ordinarily be very little raising the coach on level ground (by the jacks after you dump). So, when you start it up, the coach will rise and the jacks will come off the ground. They may or may not return to the exact same spot when you dump after airing the tires. If they are not returned to the same spot, your leveling could change or the coach could shift position. The jacks pivot outboard when they are extended to level the coach, (like a stepladder). The further they extend before touching the ground, the further out their feet will be. If they touch the ground quickly and are raised significantly afterward, they will start pivoting inward (relative to the frame). Then, if you air up, the coach lifts the jacks off the ground, they may not return to the same spot since there is relative movement (lateral and vertical) between the axle and chassis, and the jacks will pivot back outward, potentially causing a shift in jack postition. I actually did this on my coach and caused them to fold inward instead of outward when dumping while the jacks were down. This caused the coach to shift position about 6 inches sidways. I now raise my jacks before letting the coach air up.