What problem could allow the truck to rise when commanded to drain the air bags by the nanocom evolution? i.e. I told the nanocom to drain the rear bags and the solenoids clicked continuously as the truck got higher. The bags did drain but only completely drained after the second attempt with the nanocom.
A symptom I have right now is when I lower the truck it takes forever to actually lower on the rear. The front lowers rather quick. The solenoid clicks rather than just opening to drain the bags.

I had a problem after I rebuilt my eas block. 2 days in and it started acting weird. Randomly sending itself up to high ride height whilst driving. Then it wouldn't go down. Then it did, then it rose. Then it behaved. Then the front would go down and the back would only eventually go but slowly. I had the clicking going on. Turned out to be the new diaphragm I fitted. The metal cap had come off it. I replaced it and that sorted it.

It could be anything on the block but based on my experience, the dodgy diaphragm produced one of your symptoms.

If it's finding it easier to get into the rear bags than out the exhaust, you probably have a problem somewhere. Possibly a combination of the exhaust valve and non-return valves?

Would an bad diaphragm solenoid cause it? I get some air out the exhaust while compressor is on. Just replaced the diaphragm.

When you replaced the diaphragm, did you put it in dry ?
They don’t like any kind of lube, they stick..

yes it was installed dry. I had the same issue as blueplasticsoulman last time with a failure. I am thinking it has happened again. X8r diaphragms suck!

My compressor is running on/off all the time. I have the compressor cycle going on where the truck rises when the comp is on and drops after it comp stops etc..... forever! EAS is disabled until I can rip the valve block out again. NRV's are leaking slightly. Always have. Replaced with used ones and had no change. NRV's are always installed dry. The EAS on this truck has driven my completely insane at times and runs smooth other times. Valve block driver unit was replaced with new unit.

This may be a long shot mate but check the wiring from the underseat base through the passenger side kick plate / sill gaurd, i had lots of issues with my old p38 with suspension and thats why the previous owner sold it as he could not get it sorted anywhere, I did valve block drivers pipes pump etc and it still played up so I looked further (3 months of investigations) I were new to p38 so had fresh eyes to learn with and I set about wiring issues and found that because the footwell gets damp from peoples feet and the wiring under there that there were a number of wires corroded inside the plastic, I rewired them all ( some around 1 foots worth) and all was fine ever after and all worked good.
Worth a look.

I rebuilt the valve block on the weekend and replaced the Diaphragm Solenoid as the blue wires were cracked and corroded at the solenoid. It is behaving better but not completely normal. I have never actually got the EAS to work 100% in the 5 years I have owned the truck so to be able to drive the truck without disabling it is a bonus for now. There is a minor leak from the exaust while the compressor is on. The diaphragm is new. ¯_(ツ)_/¯

Have you had a look at the exhaust valve solenoid? Should be closed when inflating.

Have a look here for the diagrams and flow paths.

Thanks for posting blueplasticsoulman
Just so you are up to date on this saga the following parts have been replaced or repaired.
Compressor rebuilt
Valve block rebuilt 3 times
Driver unit replaced with new unit.
Connectors in left foot well repaired
Electrical connectors in EAS box dismantled, cleaned and tightened.
Compressor Relay
All 4 Air Springs
Diaphragm Solenoid
Dryer Unit
Zero Leaks that I can find external to the block.

The system fell back into full retard mode last night. I had to disable again. If I enable the system the rear of the truck rises while the compressor is on and the drops after the compressor stops and the the cycle continues until the compressor fries itself. Thankfully I caught it before this happened. Also the truck rises when the EAS is disabled so something weird is going on for sure. If I took saved the live data from nanocom would you be able to decipher it? I don't know how to get the info I need from the data.

Video of odd noise from valveblock exhaust. https://www.youtube.com/watch?v=p9ZX6nVdlgI

dazer2000 wrote:

This may be a long shot mate but check the wiring from the underseat base through the passenger side kick plate / sill gaurd, i had lots of issues with my old p38 with suspension and thats why the previous owner sold it as he could not get it sorted anywhere, I did valve block drivers pipes pump etc and it still played up so I looked further (3 months of investigations) I were new to p38 so had fresh eyes to learn with and I set about wiring issues and found that because the footwell gets damp from peoples feet and the wiring under there that there were a number of wires corroded inside the plastic, I rewired them all ( some around 1 foots worth) and all was fine ever after and all worked good.
Worth a look.

I redid the connectors in the foot well but I am going to dig deeper into the wiring in this area as with Canadian Winters it gets very wet. Thank you.

I would be no good at deciphering data. I just work through stuff til it's fixed. lol. Someone here will be able to though.

You're certain of no external leaks? Checked top and bottom of the air dryer? How long after the compressor stops running does it fall back to earth?

Obviously, that's quite a bit of air in there. When the compressor is off, you must be able to hear it leaking out from somewhere as it drops back down?

When you rebuilt the block, did you check the orientation of the one way valves when you put them back in? These can also get stuck and they advise not to lube the o-rings that go on them. I've just rebuilt a spare block i have. One of the one way valves was sticky. The spring was full of white powder and muck. A good blast with cleaner and a little brush and it was good as new.

The sound is rather strange from the exhaust valve. Could there be a blockage inside the block?

Do you have the ability with the nanocom to select a ride height? If so, what happens when you do that? Does it work normally or do you still get the same issue? I use EASUnlock for doing this.

Where about's are you?

It does not fall to earth. As the compressor runs the rear of the truck rises above standard (could be the whole truck as I just noticed in the rear mirror using the lines on the glass as reference) when compressor stops truck returns to standard height and starts again. With the timer relay removed the truck still rises gradually. I have to insert the relay to bring it down. No lube on check valves. I had already replaced a worn out one.
Nanocom will move the truck to any height I select. The EAS works at all heights as designed. Tank fills in just under 10 minutes while raising the truck to first height setting as door trigger does not work. EAS thinks doors are always closed. Located in Ontario, Canada.

So it's working as it should if you use the nanocom to control it? Goes up and down to any height without problems?

Ride height sensors aren't on your list of replaced parts.

Have you checked the calibrated ride heights?

If you have a faulty ride height sensor, it could be always fighting with itself to level.

I just found a post stating exactly what you have said. Thank you for confirming it.
List for the weekend include.
Check wiring from ECU to Driver unit.
Calibrate using blocks. I made some 4 years ago.
Get front left tire fixed. Slow puncture which apparently will affect the EAS.
I had replaced 2 bad height sensors with used units.
Yes it works with Nanocom as it should.

You also mention the door trigger not working. That could do with further investigation as to why it doesn't. A wiring fault can cause all sorts of havoc.

Door trigger works for everything but EAS. Also Park brake trigger for EAS does not work. On Nanocom it show park brake off and door closed no matter what I do. I am looking into all this on the week end.

So I was busy on the weekend and dug into the EAS system again.
Diaphragm replaced with old one solid disc design that does not leak.
Checked the check valves and all were installed correctly with zero lube.
Checked all wiring from the ECU to valve block. All tested good.
Found the reason the door trigger did not work. Corroded splice between the ECU, Timer Relay and BECM.
Found a leak on one of the lines from the air spring. Fixed.
Found I have 2 slow punctures on the front of the truck. Getting these fixed this week. One looses 5 Psi over night.
Found the Exhaust solenoid is cracked and possibly sticking.
I did a full calibration of the heights. They were very close to where they should have been. 3 bits out max.
The compressor no longer short cycles.

So the following symptoms persist even though I have very close to the magic carpet experience again.

1. When I was raising the truck using EAS unlock suite the air was being blown out the exhaust rather than to the spring. This happened a couple of times and then after I clicked lower and back to raise it worked fine. Sticking solenoid?.
2. When the compressor stops. Sometimes the blow off does not happen for a second or two. Sticking solenoid?

I order a used valve block and compressor off ebay today so I will have spares in a week.
I also order a rebuild kit for both. I plan on rebuilding the whole box when it arrives and drop it into my truck.
I also plan on testing the height sensors this weekend for dead spots.
Thanks for following my insanity!

So I put my old Diaphragm Solenoid back on for testing purposes. After a while it failed and these are the symptoms for anyone down the road.

1. EAS tries to lower and fails as diaphragm is closed blocking exhaust exit.
2. Air is diverted from front springs to rear spring because of weight of engine.
3. Rear Height sensors register 130 or more while the fronts register 70 making the ECU think the truck is stuck.
4. ECU requested Extended Pro and compressor activates. Compressor proceeds to fill the rear bags even more.
   I had to pull the compressor relay to prevent any issues with the air springs as they registered 156 or higher.
   I used Nanocom to level the truck and pulled the timer relay.
   The height switch lights flashed for Extended height and standard height at the same time. If I clicked standard it would return after a second to both flashing again but the truck did not move. I'm still learning about the system so I could be wrong about some stuff.