Community Forums

chunker · 09-28-2016, 08:31 PM

Last year I was adjusting and setting the ride height on the coach and I could adjust the front with the residual air in the system, engine shut down. However when I went to adjust the rear, I had to run the engine. I did run it to bring pressures back to normal and shut down. Frankly I would prefer not to be under the coach with the engine running, not that I'm afraid it will roll away, but it's noisy and disconcerting when the air dryer burps out the moisture right beside my head.

So I'm wondering. In the front compartment is an air chuck to connect a typical air hose. It can be used by the wrecker if you break down to connect there and release the brakes for towing and recovery. Can I connect my air compressor to the fitting and air up the suspension so I can make the adjustments? My compressor has an adjustable regulator so I could set it low enough not to prevent damage by overpressure. It would be a lot nicer, and quieter, to have the compressor at some distance from my work area.

For those that will raise alarm about being under the coach, I have made drive on ramps, 6 of them, that give me an additional 6" clearance. That's a safe clearance even with the suspension fully dumped.

mackwrench · 09-28-2016, 09:11 PM

Short answer, yes if the air line connection is plumbed that way.
Without knowing what brand of chassis and type of suspension, are you sure its ok to drive it up ramps and then adjust the suspension?

chunker · 09-28-2016, 09:24 PM

It's a Freightliner Evolution chassis. The ramps are 2x12 stacked up with the top level being about 15" long, and the coach sits level with 6 of them, one for each tire. I don't know if there is a check valve on the suspension side of the plumbing that would block compressed air to that part.

**JohnRR** · 09-28-2016, 09:37 PM

You should have no problem airing it up at that fitting that's what it was installed for.

FIRE UP · 09-28-2016, 10:16 PM

Quote:

Originally Posted by drwwicks

Last year I was adjusting and setting the ride height on the coach and I could adjust the front with the residual air in the system, engine shut down. However when I went to adjust the rear, I had to run the engine. I did run it to bring pressures back to normal and shut down. Frankly I would prefer not to be under the coach with the engine running, not that I'm afraid it will roll away, but it's noisy and disconcerting when the air dryer burps out the moisture right beside my head.

So I'm wondering. In the front compartment is an air chuck to connect a typical air hose. It can be used by the wrecker if you break down to connect there and release the brakes for towing and recovery. Can I connect my air compressor to the fitting and air up the suspension so I can make the adjustments? My compressor has an adjustable regulator so I could set it low enough not to prevent damage by overpressure. It would be a lot nicer, and quieter, to have the compressor at some distance from my work area.

For those that will raise alarm about being under the coach, I have made drive on ramps, 6 of them, that give me an additional 6" clearance. That's a safe clearance even with the suspension fully dumped.

Well Sir,
First off, let me ask you, does your air chuck etc. in the front, look like the one in the picture?

Now, if yours is fairly similar to this one, then, the short answer to your request if it can be used by your home air compressor to air up the system, yes. The long answer is, YES and NO.

I say it that way because:
1. If your system is like mine, (and possibly many others out there), if the air pressure on the external gauge is above 60-65 psi., and you attempt to hook up your home air compressor, it SHOULD fill the system to capacity.

2. If that air pressure in your system drops or, bleeds down to below 60 psi., there is a check valve in the system that, stops you, or any tow truck driver) from filling that system, from that port.

If you drop below 60, the only way I (again, maybe most others too) can actually fill the air system from an external source is, the schrader valve on the air dryer, under the coach.

Now, I urge you or, anyone to prove me wrong on this or, just test your own coach's air system by running the engine 'till the air system is topped off. Then, shut down the engine. Now, pump the brake pedal a few times, to bleed down the system to about 70 or so. Now, go out and attempt to fill that system back up, from your home air compressor (or any other air source you may want to use) by using that front air chuck. Your system SHOULD fill to capacity.

Now, if and when it fills from that outside source to capacity, (approximately 130 psi), then, using the brake pedal, pump it down to say, 50 psi or so. Now, go out and again, attempt to fill it. If it's like mine, your system will not fill. The incoming air will hit that check valve and stop. Your system will remain at 50 psi.

Again, this is all assuming that all your systems are like mine.

One more thing, drwwicks, you CANNOT over fill that system, using your home air compressor. The pop-off safety valve and purge valve, will do the same exact release when filling that system with external air, as it does when your engines air compressor is filling it. I know, I've done it that way several times.
Scott

steve11669 · 09-29-2016, 12:02 AM

I run the engine and wear mickey mouse ear muffs to muffle the noise.

chunker · 09-29-2016, 05:56 AM

Scott, the coach is in the shop getting a few things fixed under my extended service plan. The trip to AK "rattled" a few things. Probably in November I'll finish the annual servicing including checking and adjusting the ride height. I assume the picture is your Itasca Horizon since it looks similar to what I have.

I do wear ear plugs or muffs when working around the noisy things, but it might be easier to try the compressor method.

David

gatorcq · 09-29-2016, 06:05 AM

On my 2007 XC chassis there is a check valve to PREVENT this.

FIRE UP · 09-29-2016, 10:29 AM

Quote:

Originally Posted by gatorcq

On my 2007 XC chassis there is a check valve to PREVENT this.

There is a check valve to PREVENT what?
Scott

cbeierl · 09-29-2016, 11:58 AM

Scott, if you look on the other side of your generator (driver's side) you should see this fitting which is the "air up" connection as I understand it.

FIRE UP · 09-30-2016, 01:01 PM

Quote:

Originally Posted by cbeierl

Scott, if you look on the other side of your generator (driver's side) you should see this fitting which is the "air up" connection as I understand it.

Yes Chris,
I do have the same exact micro air manifold. And it has the schrader valve too. But, just like the reaction to filling I get when attempting to fill the system from the air chuck (pictured) and the system is below 60 psi, it too will not allow me to fill the system, or a tow truck driver. But, again, just like the air chuck side, if the system is above 60-65 psi., I can fill it with that schrader valve too, all the way up 'till the purge valve pops in the dryer. Try it like I've described and see if your system, works like mine does.

That air chuck is primarily there for "Air out" in that, it will fill bicycle tires, coach tires and anything you need air for. It can be used for AIR IN, if, the system, (at least mine) is ABOVE 60 psi. Other wise, you're filling about 6' of air line and that gauge. If I try and fill the system and it's below 60, all that happens is, that gauge goes from whatever it's sitting at, say, about 40 or so, to 130 (my home air system pressure) in about one nano-second. That indicates you're not filling anything but a small air line and the gauge, not any tanks.
Scott

cbeierl · 09-30-2016, 01:08 PM

I've never actually tried filling the system externally--the only source of air I have currently is the coach itself!

jleamo1 · 09-30-2016, 01:13 PM

Wow, so many are so different. I have an air chuck in the side bay and one up front next to the generator. The one at the generator is for a tow truck to connect to, it also has a one-way check valve so air can only go in, not out. The one on the side in the baggage compartment is the opposite, are can go out but not in. This one is for airing up tires, sports balls etc. I replaced both quick connects since I didn't have the other half.

Safetysteve5 · 10-08-2016, 10:08 AM

2014 Freightliner XCS chassis. The air OUTLET will not work as an air INLET due to a check valve in the system. This is a convenience outlet only. Tow truck INLET to unlock the brakes is the Schraeder valve on the bottom of the air dryer (this information direct from Freightliner). I tapped into a Tee on the "wet" tank and ran an air tube to my front storage bay where I installed a valve and an air INLET fitting to attach my shop air. This allows me to use shop air to keep the system full when adjusting ride height. Internal check valves will still need to be "tripped' by lowering the system pressure (brake activation) if you want both primary & secondary air systems to fill to "full".