Dumping air

Topic: Dumping air (Read 950 times) previous topic - next topic

Dumping air

September 11, 2020, 09:00:51 pm

I've never dumper all the air on my 96 U295. My coach has had damage repaired before me in all 4 wheel wells from the tires rubbing on the upper liner. If you dump the air, will it actually go that low as to do damage to the upper fender wells above the tires? I would hope not. How do you suppose all 4 wells had damage to them from the tires hitting? Why would I want to dump all the air?
Thanks

Re: Dumping air

Reply #1 – September 11, 2020, 09:07:16 pm

You might want to dump the air for storage. If someone drove the coach before the airbags inflated which would only happen if the hwh was not working you could rub all 4 tires on the bottom of the coach.

Re: Dumping air

Reply #2 – September 11, 2020, 09:09:14 pm

So when you dump it all, they can touch ?

Re: Dumping air

Reply #3 – September 11, 2020, 09:12:02 pm

Quote from: dans96u295ft – September 11, 2020, 09:09:14 pm

So when you dump it all, they can touch ?

Yes, with the early years. Not with my 2003.

Re: Dumping air

Reply #4 – September 11, 2020, 09:27:23 pm

Simple fix is add some 1" metal flat bar or ? To the plugs already on frame then it cannot sit on tires. I did and took 10 mins and that was many years ago and still there
Johnh

Re: Dumping air

Reply #5 – September 11, 2020, 11:10:09 pm

When I dump the air my tires are just below the liner but on big rolls in the road they hit and I'm just about finish fixing the liner.
John is where there is a round disk on the frame that you added the one inch to it.

Re: Dumping air

Reply #6 – September 11, 2020, 11:31:54 pm

exactly that location. I used a 2x2"piece of plywood and stuck them onto to those rings with a good quality caulking. Never moved at all.
Johnh

Re: Dumping air

Reply #7 – September 11, 2020, 11:36:48 pm

Thanks John. I like the plywood idea as it has some give and maybe I can find some heavy rubber.

Re: Dumping air

Reply #8 – September 11, 2020, 11:43:08 pm

So today I was working on the left rear brakes and noted to myself I want to dump and measure what spacers I will install. P.O. did repair patch on left rear wheel well. I installed slightly taller toyo tires and I will shim to prevent contact. On the list.
Scott

Re: Dumping air

Reply #9 – September 12, 2020, 12:15:37 am

So how many of these stops are there on the coach? Sounds like a must do project

Re: Dumping air

Reply #10 – September 12, 2020, 01:56:04 am

My wheel well tops are damaged. All four. If I put spacers on the frame then I can not level in max slope areas as well.

Re: Dumping air

Reply #11 – September 12, 2020, 05:09:08 am

Before leaving a campsite I start the engine, turn off the leveling so the coach will go to driving height and leave the engine running to bring up air pressure while I do my final walk around checking I have disconnected power, closed storage bays, antenna down, lights are all working etc and check all air bags to see I have clearance.
I have often dumped all the air and the leveling will Regularly dump all the air from one or other end of coach in parks with sloped pads.

Re: Dumping air

Reply #12 – September 12, 2020, 09:55:11 am

Dan there is eight pads. Bob I agree with wanting full Level travel, but for me not damaging the fender wells will cut down on the future repairs and corrosion issues with water migrating above fenders. Even with pads for level conditions in large slope situations there will be tire contact. Little less hopefully. John I do like the plywood idea (Softer stop) except it will collect moisture and be a cause of future corrosion problems. Hopefully these are at rest pads only. IMO
Scott

Re: Dumping air

Reply #13 – September 12, 2020, 10:38:32 am

I respect the fact that everybody has different opinions and priorities....BUT.....IMO some owners are worrying too much about a non-problem. Foretravel designed the suspension on these coaches to allow maximum leveling capability for each wheelbase. Any mechanical modification to the suspension design, such as raising the hard stops, reduces the leveling capability.

Dropping the coach all the way down to the OEM stops may or may not (depending on coach model and tire size) allow the tire to touch the top of the wheel well. If it does touch, doing so should not cause any structural damage. The weight of the coach body is still being fully supported by the suspension components. As stated above, the only way you can cause damage is by foolishly trying to drive the coach before the air bags are fully inflated. Unless it is a emergency situation (fire, flood, etc) that should never happen.

To those who are driving is such a way that your tires are hitting the top of the wheel wells on big whoop-de-doos, I'd say you need to slow down. You might also look into getting new shock absorbers.

I believe (again...a personal opinion) that the hard mechanical stops are best left unmodified. But, as always, DWMYH.

Re: Dumping air

Reply #14 – September 12, 2020, 11:06:05 am

Chuck I can honestly say that I have never noticed any levelling problem as have not been in a location (to the best of my memory) were they make it a problem. I do however understand your reasoning.
I forgot to mention I used 3/4" plywood and it has not rotted out, and have been thru a few rain storms as this is the west coast.
Johnh

Re: Dumping air

Reply #15 – September 12, 2020, 11:20:32 am

Quote from: John Haygarth – September 12, 2020, 11:06:05 am

I can honestly say that I have never noticed any levelling problem as have not been in a location (to the best of my memory) were they make it a problem.

John, I agree that in most cases modding the stops will not prevent a coach from attaining level. Our stops are still "stock". Even so, we have been in a few spots where we could not level with one end dropped all the way down and the other jacked all the way up. Sometimes, simply moving the coach a few feet forward or backward will solve the problem. Some owners carry wood ramps to help with leveling on steep slopes.

Also, I would note that (on challenging terrain) 36' coaches are easier to level than 40 footers.

Re: Dumping air

Reply #16 – September 12, 2020, 11:54:37 am

Good info. Thanks

Re: Dumping air

Reply #17 – September 12, 2020, 12:51:56 pm

Our coach is parked for the winter. When I left it I put the tire covers on, then dumped all the air. The back settled right down on the tires, thus helping to hold the tire covers in place. The front didn't go quite all the way down, but maybe I didn't wait long enough. It was within 1/2" of the tires when I left it last weekend, and with now power (batteries disconnected, no shore power) I'm sure that the front has now settled, too.

When we arrive at a campsite, unless it is a late arrival followed by an early departure, I'll put the tire covers on, then dump the air, then level. That puts the coach as close to the ground as possible and has at least one tire cover held down by the weight of the coach. More importantly, it puts the step as close to the ground as possible. That's becoming more important as time goes on.

When comes departure time, we do as much inside as possible, then I fire up the engines (Detroit first, then generator). While air is building I take care of whatever is left outside. When the air purges (usually while I'm close to it with my back turned) I know I can finish with the tire covers and get ready to pull out to hook up.

Re: Dumping air

Reply #18 – September 12, 2020, 01:09:01 pm

Quote from: kb0zke – September 12, 2020, 12:51:56 pm

Our coach is parked for the winter. When I left it I put the tire covers on, then dumped all the air. The back settled right down on the tires, thus helping to hold the tire covers in place. The front didn't go quite all the way down, but maybe I didn't wait long enough.

It may be that your coach is not parked on perfectly level ground?

The HWH system will protect the coach from being damaged by a inappropriate lowering command. If, for instance, one front wheel is in a low spot, letting ALL the air out of all four front air bags could cause the frame to twist. We GV owners (especially) know that is NOT a good thing. The two front 10 psi pressure switches (on the front 6-pack manifold) will hopefully prevent this from happening.

Quote from the HWH Leveling System Textbook, Page 10:

"The front air pressure switches on all 600 and 680 Series Leveling Systems are used during any lower functions, manual operation, automatic operation or use of the "DUMP" button. When the pressure switch for a front bag turns on, it sends a ground signal to the control box. This will inhibit the opposite side front air bags from lowering.
EXAMPLE: While pushing the right side lower button, the right front air pressure switch sees low air pressure. The front lower button is then pushed. The right front lower solenoid valve will turn on and open, but the left front lower solenoid valve will not turn on. The left front bag will not lower. This is done to prevent the front of the vehicle from twisting. If one side of the front of the vehicle is as low as it can go, lowering the other side will twist the vehicle."

Re: Dumping air

Reply #19 – September 12, 2020, 01:30:53 pm

Most if not all of my floor above the wheel well openings I think was from the worn oem Koni shocks. Bottoming and especially body roll.

Re: Dumping air

Reply #20 – September 12, 2020, 04:31:51 pm

I'm hoping my new air bags and adjusting the ride height will also help from bottoming in all circumstances

Re: Dumping air

Reply #21 – September 12, 2020, 04:35:16 pm

New bags should make no difference.

Setting ride height IS important. Only takes a few minutes to check-- let us know what your current ride highs are.

Re: Dumping air

Reply #22 – September 12, 2020, 06:31:12 pm

I just checked after repairing the wheel wells and my tires just touch the wheel wells. I'm going to look for some 1/2 inch belting
to put between the stops and frame. Also when I fined a level spot I will set my ride height, some may be out 1/2 inch.

Re: Dumping air

Reply #23 – September 12, 2020, 08:21:38 pm

Just make sure you don't leave anything resting on the top of the tires ( cord plugs ) or you could end up with the imprint of that item in your filon. When it auto level happens that is.
Don't ask how I know.

Re: Dumping air

Reply #24 – September 12, 2020, 09:02:18 pm

Quote from: Bob & Sue – September 12, 2020, 08:21:38 pm

Don't ask how I know.

Sounds like a good camp fire story.

Affiliate Notice