Factory air system used as on board air?

[EZeis]

Although this has been discussed many times here on the TDR, nobody really truly understands how the 3500 air suspension truly works. We’ve seen snippets from manuals and we’ve had some input from technicians, but nobody has told us exactly how this system is supposed to work. Mine doesn’t seem to work as other 18s have been described as working. I’ve never heard my compressor run. I’ve also never had a problem. I would like to see a shop manual that shows how it works. It’s just a bit of mystery still.

If it expels air, it's not a nitrogen system. It would run out. The compressors are extremely quiet. Does yours expel air shortly after start up? Expel air when you go to alternate trailer height? Expel air when you remove a heavy load from the bed?

Earl

 

[DeansRedRam]

Almost everytime I hop in my truck I hear a pressure relief and I assume the bags are adjusting. I always wanted to drain moisture from the system but the more I think about this "pressure relief" I hear maybe its a moisture relief.

I have heard the compressor run as well many a time.

 

[EZeis]

Almost everytime I hop in my truck I hear a pressure relief and I assume the bags are adjusting. I always wanted to drain moisture from the system but the more I think about this "pressure relief" I hear maybe its a moisture relief.

I have heard the compressor run as well many a time.

That's a moisture dump you're hearing shortly after startup.


Earl

 

[DeansRedRam]

That's a moisture dump you're hearing shortly after startup.


Earl

Roger that, thank you.

 

[JR]

I get the appeal of an onboard compressor, but Viair makes dang good portable compressors. They have long power cable and air hose and are very utilitarian. And the best part, they can be moved from vehicle to vehicle or used anywhere an engine and battery can go. I've used mine several times over in places my truck could never go. I've got the 088 which goes for well under $100 but these are really nice....

https://www.quadratec.com/products/...U8Pt-vHHLMx3O7EZdk2zt11KLn2y7JTsaAsY7EALw_wcB

 

[dieselshadow]

If it expels air, it's not a nitrogen system. It would run out. The compressors are extremely quiet. Does yours expel air shortly after start up? Expel air when you go to alternate trailer height? Expel air when you remove a heavy load from the bed?Earl

I’ve never heard mine ever run. Never heard it expel air, nothing. I can’t complain either. The truck rides well and has always been level. That being said, I haven’t put more than 1K or so in the bed or on the tongue.

 

[BigPapa]

From Alldata for a 2017, 2018, and 2019 3500. This is in the procedure for “Complete System Fill”. It also says it requires a scan tool to command the Air Suspension Control Module.

“The Air Suspension Refill Tool - 10247B is used with a nitrogen supply tank which can be acquired at a local gas supplier. The nitrogen must be Purity Class 5 (99.999% pure).”

I’d say it’s nitrogen filled or Alldata is wrong.

 

[EZeis]

From Alldata for a 2017, 2018, and 2019 3500. This is in the procedure for “Complete System Fill”. It also says it requires a scan tool to command the Air Suspension Control Module.

“The Air Suspension Refill Tool - 10247B is used with a nitrogen supply tank which can be acquired at a local gas supplier. The nitrogen must be Purity Class 5 (99.999% pure).”

I’d say it’s nitrogen filled or Alldata is wrong.

As much as mine expels air, I'd of been out of nitrogen in a week. Lol


Earl

 

[TFucili]

That part number supercedes. $600+ for a regulator and zero loss chuck. I bought a bottle, regulator, and all the fixin's to recharge my off road shocks for about $300. Must be more to it???

https://moparessentialtools.com/ite...mber=2062700020&type=tools&keyword=2062700020


And I have to agree that mine sure sounds like it vents to atmosphere when the bags dump. Not sure I buy it being a closed system on the 3500s.

 

[lpennock]

I got curious on my 2018 this morning.
Looking at the tank there is a schrader type value that would appear to work with the tool that @TFuciili linked. This would imply a closed system.

However, there is also a filtered air intake line off the compressor which implies an open system as does the burp on startup I get.

So I didn't really add much definite information on the system.

 

[lpennock]

Found this on another forum but this was from a 2015 post so take the date into consideration.

From Chrysler Tech Authority:

"The air suspension system is an open system. The air suspension reservoir stores a specified volume of pressurized air for use when the system need to raise or lower the vehicle height. If an individual pressurized component of the air suspension system is damaged and air pressure is lost, the reservoir will hold any pressure left in the component. A scan tool is used to evacuate the component. After repair or replacement of the component, a scan tool can be used to refill the component from the reservoir.

The compressor cannot refill the reservoir and complete system if all pressure is exhausted, as in a compressor assembly or valve block replacement. The system will need to be filled at the reservoir with nitrogen. For complete filling of the air suspension system after a repair (Refer to 17 - Rear Suspension/Standard Procedure) ."

"The Air Suspension Unit (ASU) is made up of two primary components, the compressor and the valve block. There is a single pressurized air line between the compressor and the valve block to maintain system pressure. Control of the air compressor and valve block is from the Air Suspension Control Module (ASCM). Diagnose the air suspension system using a scan tool.

Air Compressor The compressor runs to maintain air pressure any time the vehicle height is being changed or in the event of a small reduction in over all system pressure. Integrated reversing valves in the air compressor allow pressurized air to be moved in two directions, making this a closed system. There is a desiccant located inside the compressor for moisture protection, and an air suspension hose assembly attached to the air compressor (including a filter) which are not pressurized, and can be replaced as an assembly. If water is visible in the filter, the air suspension hose assembly and the valve block must be replaced. An air suspension temperature sensor is attached to the air compressor bracket to monitor ambient air temperature for protection of the compressor."

 

[dieselshadow]

See, very confusing.... LOL

 

[EZeis]

See, very confusing.... LOL

Not at all. My 18 3500 has an open compressor system. Nothing confusing about it at all. I can tell this by looking at it. I can also tell this by hearing it expel air when adjusting the bags and the startup purge. A sealed system wouldn't expel at all and would eventually need topped off as rubber bags won't hold nitrogen in forever. While nitrogen slows down the loss compared to atmosphere air, it will still eventually leak through the rubber. Also any system leaks.

Earl

 

[AH64ID]

My 19 is definitly Nitrogen

Any pics of the setup?

I’ve looked close at a 19 and that one was identical to my 18, which is absolutely an open system.

Just today I stated it up and it purged as the wife walked by the vent/intake and she jumped

 

[DogramTD]

I just tapped into my system adding another tank and balancing line with a check valve to prevent air from going back into the OEM tank from the steel tank I installed....then I read this thread ‍

 

[kthaxton]

As much as mine expels air, I'd of been out of nitrogen in a week. Lol


Earl

Well, only until approximately 79% Nitrogen.....it won't go any less than that.

 

[sag2]

It is designed to be a (mostly) closed system. The compressor is there to add any make up air for small leaks in the system, but it's primary job is to transfer air (Nitrogen) back and forth between the tank and bags. It should not "vent" anywhere except to the tank. If there are no leaks, in theory the system would never have to add any outside air to the system.

 

[Cummins12V98]

It is designed to be a (mostly) closed system. The compressor is there to add any make up air for small leaks in the system, but it's primary job is to transfer air (Nitrogen) back and forth between the tank and bags. It should not "vent" anywhere except to the tank. If there are no leaks, in theory the system would never have to add any outside air to the system.

Best answer yet!!! That is how I understood it in 2015.

 

[AH64ID]

It is designed to be a (mostly) closed system. The compressor is there to add any make up air for small leaks in the system, but it's primary job is to transfer air (Nitrogen) back and forth between the tank and bags. It should not "vent" anywhere except to the tank. If there are no leaks, in theory the system would never have to add any outside air to the system.

Which model/year are you referring to?

My 18 doesn’t work that way at all, nor does dads 17 3500.

 

[AH64ID]

Best answer yet!!! That is how I understood it in 2015.

It’s how we all understood it at the debut, but not how the 3500 system works for some, if not all, years.