Air Suspension question

mnm#2 you are correct in the case of an massive loss of air suddenly unless a check valve is sticking but under the condition stated it is possible. Brake applications over 20 psi are wasteful and excessive however most motorhomes and new commercial vehicles are no longer built with them, it's a shame because it also shows aggressive braking caused by short following distances and driving too fast with the load.

I never use fast idle either and I never have had my coach dragging because of the use of the air brake. That is why I suspected maybe there is some other problem which could be the height valve. It is not uncommon to see them go bad, and the air bags either the front or the rear two separate valve if they get stuck in the exhaust position the air bags will not inflate.

My air pressure will build up pretty fast even when the air has been dumped. It should not take anymore then five minutes.

Some of these posts are funny especially the one's that specify for this person to go and study a commercial test book to learn about air brakes. It does not take much to get used to driving a coach with air brakes versus hydraulic brakes. What I would suggest is to take the coach out in the country and drive those back roads and get the feel of driving a diesel pusher. Once you drive a few miles you would never go back to a gasoline motor home. You would feel more confident driving that big diesel then you would driving your automobile.

After the air tanks are filled(120psi) ,The airbrake system is protected from the suspension system with a check valve in case of a failure(broken air line or air bag) in the suspension so you will still have brakes,your air compressor should kick in @90psi and continue to 125psi. Though you have automatic air dryer you should still open and drain the air tanks manually

The OP said he had used enough brake applications the air level was down in the reservoir system which can create a possible situation where the air pressure in the suspension bags exceeds what is available in the air system. If the ride height valve keeps demanding air due to an incline or uneven driveway under this condition the suspension will start bleeding back towards the reservoir. Air brake courses and operating manuals will not tell you about this condition.

dons2346 wrote:

Mike and Trish wrote:

dons2346 wrote:
" Then turn on the Cruise Control. Press the Set button on the steering wheel. This will increase the idle to about 1500-1800 RPM."

Yup, how to make friends in a campground

I don't know, which would you prefer -- higher revs/shorter time to air up, or the guy who lets it idle for 20 minutes or longer? The "fast idle" feature is there for exactly that purpose -- get aired up and go.

There is no need to let it idle for 20 minutes either. I can dump all the air in my bags, start the coach and be at ride height in less that 5 minutes and go. I never use fast idle

SAME HERE!

When starting, your alarm will go off when your air tanks are at pressure and you'll hear it blow off. Meaning your tanks are full. Then switch the air bags lever to auto. It will (should) then inflate your air bags. By going outside you can visually confirm the coach is raising to ride height. Again, when the tanks reach pressure it will blow off and the coach should be aired up. Visually you should be able to determine this.

As others noted you should learn to test for leaks as some of your other comments lead to believing there is a issue if deflating while driving.

The air dump lever should be dumped before extending your jacks ( at least in ours). But we have the hydraulic system, other manufactures and higher end coaches use a air system to level if you have that. I always dump the air when not driving and parked for some time.

Starting your engine and run time is another thread all together. But most of what you hear is long enough to pull in your slides, retract your jacks, and inflate your air ride. Some coaches have a different procedure, but the engine must be on in ours to bring the slides in or operate the hydraulic jacks.

RayChez wrote:
The part that some of the Monaco experts have not addressed is how come the air bags deflate so much while trying to park the coach. To where the OP says the coach is dragging. To me it sounds like he might have a bad air leak somewhere in the system. The air bags should not deflate because of the use of the air brakes.

HWH system will allow the coach to drop all the way down prior to extending the jacks, but it does not deplete the brake system air, just the ride system.

I deploy the jacks manually prior to reducing the air pressure for the leveling system to work. that simply reduces the run time for the jacks under a load.

The part that some of the Monaco experts have not addressed is how come the air bags deflate so much while trying to park the coach. To where the OP says the coach is dragging. To me it sounds like he might have a bad air leak somewhere in the system. The air bags should not deflate because of the use of the air brakes.

To the OP....time for your homework assignment. I assumed you purchased the coach new but it appears you did not or at least didn't get all the necessary paperwork with it. Here's your assignment.

Monday morning, although it's a holiday, so you might have to wait until Tuesday..but, write down either your coach number, which is found on the RVIA sticker just outside your front door, or copy the last six digits of your VIN. Call Monaco @ 800-509-3417. Ask them to email you the build sheet and any documents they have pertaining to your coach. The build sheet will give you MODEL AND SERIAL numbers of all your included equipment, A/Cs, W/D, inverter, etc. etc. Armed with this information you can then research how to's of your particular piece of equipment..It's also a handy reference if something breaks.....Dennis

Sprink-Fitter wrote:

How is warming up a diesel motor for 10 minutes a waste? It probably took 3/4 of that to build air pressure.

7 and 1 half minutes to pump the air up? there has to be some thing wrong there.

My air system has automatic water bleeds, it requires nothing from me to dump the water collected in the tanks.

After the coach sets an extended time our tanks will be empty, and it takes about 3-4 minutes at Idle to hear the tank discharge activate.

My routine is:

retract the slides. start the diesel, retract the levelers, walk around disconnect the sewage hose, disconnect the electrical, check to see all jacks are up, walk thru the coach insure the interior is safe to drive, lock the slides. pull away.