Air Suspension head scratcher

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Tapps33

Full Access Member
Joined
Jul 23, 2019
Posts
301
Reaction score
181
Location
Bath, Maine
Now that the valve block has been swapped, lets take a look at the old one and see if we can't figure out what went wrong.

Initial separation:
IMG_7141.jpeg


Nothing seemed to be a "smoking gun" if you will, but I pulled the plungers out and this is how they looked:

IMG_7143.jpeg


Again, not too bad. a little bit of white dessicant on them, but nothing too crazy, especially considering I'm on my 3rd compressor and the valve block is 13 years old.

Internal manifold looks pretty clean too:

IMG_7144.jpeg


However, I did see a spot on the far solenoid o-ring that I tried to get a picture of, but it's really hard to see unless the light it "just" right:

IMG_7142.jpeg


It appears to be a blow out area, going past the outer o-ring. I could be wrong, but it would make sense as I believe that's the RR solenoid valve.

Either way, the new valve block is in! I'm going to let it set overnight without pulling any fuses to see what happens. If it drops again by tomorrow morning I'll let you all know! If it doesn't...well, I'll probable tell you all that too!
 

Longtrail

Full Access Member
Joined
Sep 3, 2022
Posts
257
Reaction score
128
Location
Ann Arbor
Great work and photos - Thank you for sharing. Looking at the old valves I think there's enough desiccant for the valves to be leaky. Mine looked similar! By cleaning, lubricating (with silicon grease) and adding new o'rings I was also able to stop my suspension from dropping. I don't think it takes too much desiccant to cause issues!

Keep us posted, curious to see where things are this morning...
 

Tapps33

Full Access Member
Joined
Jul 23, 2019
Posts
301
Reaction score
181
Location
Bath, Maine
Sooooooo.....still fell down over night. Looks like the next step is the cross over air tube....but it's still on back order. If that doesn't get it, the only other thing I can think of is the RR air strut is leaking. If after all that it's still falling, as the position sensors are all reading correct, the EAS module itself would be the only other thing I can think of....but that sounds really far fetched.

On a good note, I'll pretty much have a brand new air suspension system when this is all said and done. o_O
 

ryanjl

Full Access Member
Joined
Dec 31, 2015
Posts
3,070
Reaction score
1,837
Location
KCMO
If you are unplugging the EAS fuse at night, the EAS ECU won't be on to do anything to make it drop overnight.

At this point, I'd guess it's your right rear strut.
 

Tapps33

Full Access Member
Joined
Jul 23, 2019
Posts
301
Reaction score
181
Location
Bath, Maine
If you are unplugging the EAS fuse at night, the EAS ECU won't be on to do anything to make it drop overnight.

At this point, I'd guess it's your right rear strut.
It's definitely looking more and more like it....really thought we had it with the rear valve block.

I keep hoping I'll get a shipping notification for the hose, but here I wait.
 

ryanjl

Full Access Member
Joined
Dec 31, 2015
Posts
3,070
Reaction score
1,837
Location
KCMO
I'm not familiar with the routing for that hose. Is it somewhere you can spray it with soapy water? Regardless, unless your vehicle has been in an accident or something, the hoses aren't generally in locations where they can chafe or rub on anything to spring a leak.
 

Tapps33

Full Access Member
Joined
Jul 23, 2019
Posts
301
Reaction score
181
Location
Bath, Maine
It pretty much runs up along the frame cross member, around the parking brake actuator, and then over top off the passenger exhaust pipe and through to the shock mount. Unfortunately, the majority of the tube is hidden...or at least so far behind everything I can't spray it...cause I've tried. I can only really hit the ends where it pops back out to the air strut....heck, you can't even really get to the valve block side unless you remove the lower supply line and rotate the valve block.

I agree, thus far, I have never had an issue with the hoses...or even really heard of a fractured hose, which leads me to the conclusion the RR air strut is my issue. I was just really hoping I didn't have to replace them...cause now I'm toying with the idea of seeing if I can modify the system to add ADDS. In theory it's just the 3 accelerometers, the ADDS module and the new ADDS Air struts....ok, and a little bit of wiring and some creative CCF editing.

Or, I could just replace it with a standard one....but where's the fun in that?
 

Longtrail

Full Access Member
Joined
Sep 3, 2022
Posts
257
Reaction score
128
Location
Ann Arbor
Perhaps it's worth checking the pipe going in to the air spring (again)? Is there any reduction in how much it falls overnight, in other words has the valve block slowed it down at all? I concur on the routing of the pipe, I tried following it just visually and had a rough time!

What is ADDS? Coil spring replacement?... So sorry you're having to deal with this.
 

Tapps33

Full Access Member
Joined
Jul 23, 2019
Posts
301
Reaction score
181
Location
Bath, Maine
Perhaps it's worth checking the pipe going in to the air spring (again)? Is there any reduction in how much it falls overnight, in other words has the valve block slowed it down at all? I concur on the routing of the pipe, I tried following it just visually and had a rough time!

What is ADDS? Coil spring replacement?... So sorry you're having to deal with this.
Yeah, for what should be a pretty simple system, tracing this one particular glitch has been a bit of a pain.

When my wife gets home tonight I'll pull the fuses and take some measurements again and see if there's a fall vs. time difference from before.

It's actually ADS, and it stands for "Adaptive Dynamics System." More specifically, it's the electronically adjustable air struts from the RRS. It uses 3 accelerometers as well as inputs from the BCM, RLM engine PCM and a few other inputs to constantly adjust the stiffness of the 4 air struts.

All that is to say I'd have to buy 4 new air struts, an Adaptive Damping Module, the 3 accelerometers, then wire everything together, then get it programmed to the the vehicles system. Not gonna lie, I may hit up the folks at GAP and see if they've ever tried this.

....or, I just put a new strut on the RR and be done with it...I'm not sure how crazy I want to get with this.

Before you say anything, yes, I acknowledge that I have a serious problem of trying to upgrade EVERYTHING! (Hence why the next addition, once I'm finished building it, is the supercharged 5.0 AJ133!!!!...which all stemmed from the fact that my timing chains are due...like I said...I have a problem.)
 

Longtrail

Full Access Member
Joined
Sep 3, 2022
Posts
257
Reaction score
128
Location
Ann Arbor
I have to think you don't have kids!... I can't imagine this much freedom and I'm lucky in that I've managed to get as far as I have! Anyway; thank you for explaining the adaptive suspension system, it's a very cool idea! I certainly like the idea of a softer ride on the dirt roads and then stiffen her up as I drive on pavement! I always though the Cadillac Magnetic Ride control was a pretty neat solution. Not sure I know yet (how you stiffen an airspring) without changing the ride height, it must be some sort of variable piston diameter (a worthy web search when I have a minute). Keep us posted...
 

Latest posts

Members online

Forum statistics

Threads
36,321
Posts
218,675
Members
30,523
Latest member
Nico3dd
Top