Xsen
Junior Member
Hey everyone,
Been thinking of writing this last fall, but decided to actually test everything first. Well, one winter later I can confirm that it works perfectly fine! So.
I hope this will be useful for anyone driving a truck with air suspension, who wants to keep it that way and not convert to regular springs. That was exactly my reason to do this mod.
Also, a disclaimer, I am not the original mod inventor, so all credit should go to Shezl (that’s how he’s known at Drive2 website). I just took my time to do this write-up. And yes, do it at your own risk.
The basic idea is this: troubles with air suspension that cause the truck to suddenly fall on one or more corners or get stuck elevated during low temperatures are most often caused by moisture in the airlines. Once the passage freezes, it blocks the air until the ice block melts, hence the fact that a night at a warm garage might heal the suspension. Till it freezes next time.
The Gen4 Ram air suspension is not exactly a closed circuit, though it does recycle the air a lot and uses the air tanks under the truck bed to store the air under pressure. However, there are times when the air volume needs to be increased or decreased significantly, i.e. when you load the truck, so the system may take some air in or purge some out. This is just to illustrate the fact that regular outside air (and moisture!) can be introduced into the system.
So, what we need is making sure that the air in the system is kept dry at all times, regardless of whether it’s stored in the tanks or sucked from the outside. The simplest way of doing so is installing an air dryer and running the air through it. On a Gen4 Ram there is only one place, where this can be done without triggering a DTC in the suspension control module – that is the supply line from the compressor to the tanks.
Here’s what we’ll need:
1. One WABCO 4324102227 air dryer cartridge or any similar unit, like this:

2. Two fittings 6mm – 1/4 , something like Camozzi 6512:

3. Seven ft (2m) of a 6 mm plastic frost-proof air line.
Here’s the hard part - this mod requires some fabrication, namely a plate adapter that we’ll use to connect the air dryer cartridge to the air lines. This can be fabricated from either steel or aluminum, I used the latter to save weight and skip the painting part. Here’s the CAD of the plate for the WABCO cartridge that has M39x1.5 thread.

All dimensions provided on the drawing are metric!
Speaking of the installation it’s nothing especially challenging and can be easily done by a DIY mechanic with basic skills. A 4-point lift is a great help too, though not mandatory. Here’s the routine:
1. Remove the F50 fuse from the fuse box under the hood, to disable the air suspension control unit.
2. Lower the spare tire. Wash, if needed.
3. Raise the truck on a lift or jack the rear right wheel, take the wheel and the wheel liner off.
4. Take the plastic shield on the rear side of the wheel well to get better access.
5. Take that stone shield thingy off the compressor.
6. Looking at the air tanks from the wheel well you’ll see this:

The red boxes on the photo mark the connection points for the nitrogen filling equipment. The green box marks the line that you need to disconnect.
7. Open either of the plastic caps, marked by the red boxes. Using a Philips screwdriver or a similar tool press the tip inside the connector to release the pressure in the tanks. Be careful, this will cause lots of dust flying around, so you might want to cover your eyes and face. The tanks are connected, you don’t have to do both connectors. Notice that your airbags would still be pressurized, so the truck could stay level. Once all the air is out, reinstall the plastic cap and move on to the next step.
8. Using a 12mm wrench unscrew the airline from the tanks. Do not apply excessive force here, it goes out pretty easily.
9. Get the other end of this line out of the compressor.

The yellow arrows point at the airline, and the green arrow points at the fitting, that you need to remove.
10. Carefully remove the factory fittings from the airline. Insert the airline that you’ve bought into the fitting, leaving about 3-4 mm, not more, sticking out of the fitting.
11. Re-install the fitting with the newly connected airline to the air tanks bracket. Again, be very careful, the bracket is made from plastic. Tighten the fitting, and give the airline a firm pull to properly seat it in the fitting.

12. Route the airline to the spare tire mount point. There’s a convenient place to pull the line out of the frame right next to the plastic tube. Mark this line with a piece of electric tape just to remember which line goes where.

13. Cut the airline, leaving about 2ft hanging.
14. Reinstall the factory fitting on another piece of 6mm airline and install this fitting on the compressor side. I failed to take a picture of this step, but I think you’ve got the idea. Don’t forget to pull the line to seat it. Route this airline to the spare wheel, out the same hole and cut the line about 2ft down from the frame.
15. Install the Camozzi fittings onto the plate adapter. Do not overtighten, or you might damage the o-ring on them. Stick the airlines into the fittings till they stop and give them a firm pull, they should stay in the fitting. At this point you’ve completed the airline assembly.

16. Get the spare tire back on its cable and let it hang on it. If you’re working on the ground, let it just lay there.
17. Install the WABCO cartridge onto the adapter plate, cover it in something soft, like a few layers of fabric, etc. and put it into the spare tire. The airline length should be more than enough. This is the easiest way to keep it, lowering the spare once or twice a year for cartridge replacement, and the fabric would keep things quiet, but you might also consider fabricating a bracket for the adapter plate and fixing it somewhere on the frame nearby the compressor, there are a few options.

18. Reassemble everything from that stone shield to wheel well liner and the wheel, pull the spare up and lower the truck.
19. Put the F50 fuse back and start the engine. Let the compressor pump the air into the tanks.
That’s it, now you have a dryer in the system, that will keep it moisture-free under any conditions. Time for a cold one.
A few words on the nitrogen. The service manual says that you must use 99.999% nitrogen to fill the air suspension system. This might be a great idea, and if you’ve got a tank of nitrogen – just connect it to the tanks after step 17 and fill it up until the pressure reaches 12 Bar. But then again the system is not closed-circuit, air may enter and leave the system, so… You’ll have to decide for yourself. I filled it with regular air last fall and had zero issues, so that’s my 2c.
After you install this mod it’s quite recommended to operate your suspension in an active sort of way, several drives each day, running the height up and down, etc. Warm weather also helps.
In fact, late spring would probably be the best time for the mod, you’ll have plenty of warm weather to dry the air in the system until next colds come.
Been thinking of writing this last fall, but decided to actually test everything first. Well, one winter later I can confirm that it works perfectly fine! So.
I hope this will be useful for anyone driving a truck with air suspension, who wants to keep it that way and not convert to regular springs. That was exactly my reason to do this mod.
Also, a disclaimer, I am not the original mod inventor, so all credit should go to Shezl (that’s how he’s known at Drive2 website). I just took my time to do this write-up. And yes, do it at your own risk.
The basic idea is this: troubles with air suspension that cause the truck to suddenly fall on one or more corners or get stuck elevated during low temperatures are most often caused by moisture in the airlines. Once the passage freezes, it blocks the air until the ice block melts, hence the fact that a night at a warm garage might heal the suspension. Till it freezes next time.
The Gen4 Ram air suspension is not exactly a closed circuit, though it does recycle the air a lot and uses the air tanks under the truck bed to store the air under pressure. However, there are times when the air volume needs to be increased or decreased significantly, i.e. when you load the truck, so the system may take some air in or purge some out. This is just to illustrate the fact that regular outside air (and moisture!) can be introduced into the system.
So, what we need is making sure that the air in the system is kept dry at all times, regardless of whether it’s stored in the tanks or sucked from the outside. The simplest way of doing so is installing an air dryer and running the air through it. On a Gen4 Ram there is only one place, where this can be done without triggering a DTC in the suspension control module – that is the supply line from the compressor to the tanks.
Here’s what we’ll need:
1. One WABCO 4324102227 air dryer cartridge or any similar unit, like this:

2. Two fittings 6mm – 1/4 , something like Camozzi 6512:

3. Seven ft (2m) of a 6 mm plastic frost-proof air line.
Here’s the hard part - this mod requires some fabrication, namely a plate adapter that we’ll use to connect the air dryer cartridge to the air lines. This can be fabricated from either steel or aluminum, I used the latter to save weight and skip the painting part. Here’s the CAD of the plate for the WABCO cartridge that has M39x1.5 thread.

All dimensions provided on the drawing are metric!
Speaking of the installation it’s nothing especially challenging and can be easily done by a DIY mechanic with basic skills. A 4-point lift is a great help too, though not mandatory. Here’s the routine:
1. Remove the F50 fuse from the fuse box under the hood, to disable the air suspension control unit.
2. Lower the spare tire. Wash, if needed.
3. Raise the truck on a lift or jack the rear right wheel, take the wheel and the wheel liner off.
4. Take the plastic shield on the rear side of the wheel well to get better access.
5. Take that stone shield thingy off the compressor.
6. Looking at the air tanks from the wheel well you’ll see this:

The red boxes on the photo mark the connection points for the nitrogen filling equipment. The green box marks the line that you need to disconnect.
7. Open either of the plastic caps, marked by the red boxes. Using a Philips screwdriver or a similar tool press the tip inside the connector to release the pressure in the tanks. Be careful, this will cause lots of dust flying around, so you might want to cover your eyes and face. The tanks are connected, you don’t have to do both connectors. Notice that your airbags would still be pressurized, so the truck could stay level. Once all the air is out, reinstall the plastic cap and move on to the next step.
8. Using a 12mm wrench unscrew the airline from the tanks. Do not apply excessive force here, it goes out pretty easily.
9. Get the other end of this line out of the compressor.

The yellow arrows point at the airline, and the green arrow points at the fitting, that you need to remove.
10. Carefully remove the factory fittings from the airline. Insert the airline that you’ve bought into the fitting, leaving about 3-4 mm, not more, sticking out of the fitting.
11. Re-install the fitting with the newly connected airline to the air tanks bracket. Again, be very careful, the bracket is made from plastic. Tighten the fitting, and give the airline a firm pull to properly seat it in the fitting.

12. Route the airline to the spare tire mount point. There’s a convenient place to pull the line out of the frame right next to the plastic tube. Mark this line with a piece of electric tape just to remember which line goes where.

13. Cut the airline, leaving about 2ft hanging.
14. Reinstall the factory fitting on another piece of 6mm airline and install this fitting on the compressor side. I failed to take a picture of this step, but I think you’ve got the idea. Don’t forget to pull the line to seat it. Route this airline to the spare wheel, out the same hole and cut the line about 2ft down from the frame.
15. Install the Camozzi fittings onto the plate adapter. Do not overtighten, or you might damage the o-ring on them. Stick the airlines into the fittings till they stop and give them a firm pull, they should stay in the fitting. At this point you’ve completed the airline assembly.

16. Get the spare tire back on its cable and let it hang on it. If you’re working on the ground, let it just lay there.
17. Install the WABCO cartridge onto the adapter plate, cover it in something soft, like a few layers of fabric, etc. and put it into the spare tire. The airline length should be more than enough. This is the easiest way to keep it, lowering the spare once or twice a year for cartridge replacement, and the fabric would keep things quiet, but you might also consider fabricating a bracket for the adapter plate and fixing it somewhere on the frame nearby the compressor, there are a few options.

18. Reassemble everything from that stone shield to wheel well liner and the wheel, pull the spare up and lower the truck.
19. Put the F50 fuse back and start the engine. Let the compressor pump the air into the tanks.
That’s it, now you have a dryer in the system, that will keep it moisture-free under any conditions. Time for a cold one.
A few words on the nitrogen. The service manual says that you must use 99.999% nitrogen to fill the air suspension system. This might be a great idea, and if you’ve got a tank of nitrogen – just connect it to the tanks after step 17 and fill it up until the pressure reaches 12 Bar. But then again the system is not closed-circuit, air may enter and leave the system, so… You’ll have to decide for yourself. I filled it with regular air last fall and had zero issues, so that’s my 2c.
After you install this mod it’s quite recommended to operate your suspension in an active sort of way, several drives each day, running the height up and down, etc. Warm weather also helps.
In fact, late spring would probably be the best time for the mod, you’ll have plenty of warm weather to dry the air in the system until next colds come.