Air pressure change

[TXBart]

I ran my generator yesterday to give my batteries a charge and while I was playing and wishing I was on the road I decided to run the engine.

It started right up, ran like a top. Air pressure built normally, ran up,to top of the gage and "huffed" then I noticed the front gage slowly drop to about 120psi, rear gage stayed at almost 150 psi until I pushed the brakes. I pumped the brakes several times to drop pressure and let it rebuild. Did the same thing every time. I realized I have never paid attention in the past. I know they go to top of the gage but run a little lower with the front slightly lower than the rear, both at 120 psi or above.

Has anyone else noticed the front lowering pressure?

[Skip426]

Possible that the air suspension operates, from the front tank, only, you would need an air system diagram for your coach. Should be checked out, because you may have a slow leak somewhere in the system.
My coach, after the air system is up with no brake application, gauges are stable , with the same reading.
I know , I've got an older , brand X coach, as far as your concerned , but some systems are fairly common.

[TXBart]

Skip,

Prior to this coach the closest I had been to air brakes was driving next to an 18-wheeler on the interstate so any information is good to me! Thanks!

[loisjop]

My air pressure will go to about 130-140. When the pump shuts off they will initially drop about 5psi but then they will hold that for quite awhile. I have timed the pump cycle when on the road and if I don't have to use the brakes it will cycle every couple of hours.
If I build the pressure when parked the rear tank will stay above 65psi for a week or more. The front tank will bleed down to 65 psi in 3 or 4 days. I think my air system is very tight although I had a couple of leaks in the beginning. Noel

[TXBart]

Noel - You describe mine as well. Thanks!

[wmpbauer]

Use soapy water and look for leaks, guys.

[Skip426]

Originally Posted by loisjop

If I build the pressure when parked the rear tank will stay above 65psi for a week or more. The front tank will bleed down to 65 psi in 3 or 4 days. I think my air system is very tight although I had a couple of leaks in the beginning. Noel

Noel ; you say you had leaks in the beginning. Were they in the air suspension ? Or in other sections of the air supply ?
The air suspension portion of the system would have a supply shut off, to stop a major air leak in that portion from depleting all the air and rendering the coach immobile .
In another post , a member had a link to a " Motor home air system for beginners hand book " I'll see if I can track it down.

[DougTex]

I have the same situation. Both Motor Home Specialists and customer service at Entegra say's that is normal. My front gauge reads 110-120, assuming that the 65 at the top of the gauge is half and the line at the end of gauge is 130, with the 150 signage below the end of said gauge. Hopefully, that is not too confusing, and someone correct me if I am wrong.

[loisjop]

Originally Posted by Skip426

Noel ; you say you had leaks in the beginning. Were they in the air suspension ? Or in other sections of the air supply ?
The air suspension portion of the system would have a supply shut off, to stop a major air leak in that portion from depleting all the air and rendering the coach immobile .
In another post , a member had a link to a " Motor home air system for beginners hand book " I'll see if I can track it down.

The original leaks were in the air supply, because my air would go to zero or the rear tank fairly rapid. Now the air takes a long time to get down to 65psi where the proprietary valve for the brakes holds it for even longer. Once it reaches 65psi it will eventually go on down, but it takes several days. Noel

[brobox]

One thing to add Vance, the gauges will fluctuate 5 or 10 PSI while going down the road. That is the air suspension using air doing it's thing and normal

If the 2 gauges do not hold equal amounts of air with the engine off and sitting for an hour, then there is an air leak. On my previous coach I had two major air leaks, a ride height valve and a front air bag manifold, both of those could be heard outside of the coach. Along with several loose air lines over the years, those take soap solution to find. The gauges would show 5-20 PSI air loss in the hour. My Anthem was delivered loosing a 100 PSI an hour, so I guess air leaks are common for me.

What Noel described is normal operation.
I noticed the gauges on the Entegra are numbered 1 and 2. Does anyone know which one is the brake system?

[TXBart]

My gage are "Front" and "Rear" and both deplete with the brakes.

[brobox]

Originally Posted by TXBart

My gage are "Front" and "Rear" and both deplete with the brakes.

Opps, I should have said front and rear, but that is strange that both gauges go down using the brakes. Not having my Anthem yet, I don't know, but one should be for air brakes only. I hope that is something they haven't changed.

After thinking about it, they may have the gauges for front and rear suspension, but I don't know. If that is the case, I would like to know which one the brakes are connected to as that is the important one to watch.

[757driver]

Originally Posted by brobox

Opps, I should have said front and rear, but that is strange that both gauges go down using the brakes. Not having my Anthem yet, I don't know, but one should be for air brakes only. I hope that is something they haven't changed.

After thinking about it, they may have the gauges for front and rear suspension, but I don't know. If that is the case, I would like to know which one the brakes are connected to as that is the important one to watch.

From my understanding the rear (primary) is for the rear brakes and the front (secondary) is for the front brakes.

[papaw1]

Secondary meaning front brakes and any other air operated components.