Hello,

I have a disco II 2001, 103,000. I just did an oil change. The three amigos are on but that's not my real problem here. When I drove the vehicle last the brake, off road light and the leveling light did not turn off after few seconds when starting the vehicle. But when I got to my destination then came out and turned the vehicle on the lights were off except for the three amigos.

This morning I come out to see the air suspension on both sides deflated. I had just replaced both bags around the 90,000-93,000 mile mark. And yes I know I should have just replaced with the springs...wouldn't being have this problem right now. Is it possible for them to both go out at the same time this quickly?

I am on a college budget and don't have a hawkeye reader (its on my wish list for x-mas this year). I was hoping maybe someone might have a few suggestions this way I could avoid going to the dealership to diagnosis.

Thank you

 

If both sides dropped exactly the same amount, it is not the bags but an electrical issue that can only be found using a scanner with the specific Rover software.
If you want more help, send me your number and I'll call you.

 

this is exactly what I was worried about with my SLS..I would replace the bags and something else would mess up..so I installed coils. Give Mike a call, he'll be able to help you out...post back with the fix.

 

I've never heard of this happening before.. mine both leak SOMETIMES but it's an actual LEAK and only when I'm messing with the back of the car, so I'm thinking my bags are just cracked (happens much more under heavier loads or with full tank of gas, towing, etc).

TWO things have to happen for the bags to lose air electronically - the SLABS unit has to command the control valves for BOTH bags to open, then it also has to command the air dump valve on the compressor to open - as a previous poster mentioned, the two sides are NOT connected before their individual control valves.

This is weird, I feel like something else is going on here. Don't ditch the system yet - I just rebuilt mine with an aftermarket compressor and solenoid valves and it's working like a beauty (vehicle is 11 years old and has 154k miles on it). I spent LESS $$ finding cheap (yet better built) aftermarket components than any of the coil-spring conversion kits, and I still keep my caddy-smooth air-ride and auto-leveling for safe trailering and hauling which is very important to me! Especially with horse trailers.

 

Just wanted to give an update.

After two days of overnight deflation then filling up with air upon starting vehicle. On day three they didn't deflate completely just half. Today no air has escaped they are at normal inflation. I have no idea what would cause this.

I think it has something to do with running in sport mode which is something I never did until the last two weeks (fear of wasting more gas...these trucks are thirsty). I ran the vehicle in sport mode and then this happens. I took it off sport mode on Friday I believe. I think their is probably a bigger issue at hand but for now as long as she doesn't sag I am going to leave it alone for now.

Thank you Mike for the help and for everyone else thank you.

 

sport mode just changes the shift points of the transmission. I don't think it has anything to do with the SLS. Check the resistance of your ride height sensors, they're probably just potentiometers and should be easy to check. BTW I have all the SLS parts off my DII for sale if you need anything.

 

Doesn't have anything to do with sport mode - that's an "internal" program / circuit to the transmission system alone.

It can't be the height sensors if the vehicle inflates to the correct height once the it's running (they're either broken or working).

When you replaced the air bags did you change the air line? If not, did you buy new compression fittings for the top of the air bags? Did you replace the bags with the Arnotts or OEMs? I'm not sure if they use different fitting types (most of my SLS system now uses the push-lock air fittings since the crush fittings SUCK).

I had a leaking crush fitting in the air compressor/valve block box after replacing the dump valve solenoid in there, it's possible that you have a similar issue on your air bags if the fittings or lines are damaged - if the leak is slow enough then obviously it won't be a problem when the car is on (it'll just use the compressor more often).

The system also seems to be sensitive to ambient temperatures and loads in the back of the vehicle (including gas) if there IS a leak. As I said before, sometimes mine will be fine (even after more than a week) but other times it'll be gone in a day. Either way, there's a leak.

EDIT: If you're done messing with this thing, a sure way to discover the weakest link would be to fill your tank to the max (29 gallons is 177 lbs!) throw some stuff in the back (or hitch a trailer if you can) press the "off road" button to bring it to max height (gives you higher pressures AND better visibility of the lines/fittings) then spray some soapy water onto the bags AND fittings/air lines on the top of the bags. I'm 99.9% sure you'll find something.

The bottom line is that if your system functions and inflates to the correct height when the vehicle is running, then there really can't be any major faults or failures electronically - my money is still on a leak.

 

I don't know what I'm talking about for the most part, most of what I know is from these forums.

However, I was having the same problem (still am) with my bags as it would seemingly totally deflate overnight or after each use, and then re-inflate if I drove it 2 hours or more later. Sometimes they would stay properly inflated for 2 or 3 days. After I had the truck up on a lift last week, it was quite obvious that my passenger side bag has a leak. It confuses me as to why it only deflates sometimes, but I would venture to guess that the leak is around the "fold" toward the bottom of the bag and its just a matter of positioning.

So what I'm trying to say is, although it seems random and that it isn't a leaky bag, CHECK AGAIN. After I saw the passenger bag totally deflated on the lift with the drivers totally inflated, I now notice that the passenger side is always further deflated (resting on the bump stops) and that the drivers side just deflates to keep it level?...though my drivers side never goes down quite as far, never on the bump stops.

I'm now deciding between replacing both bags and hoping for the best (since they are both 11 years old), or converting.

My $.02

 

I should have read this post first...

 

I don't agree. I've seen numerous electronic components act flaky because of a bad connection or too much heat...not that the ride sensors get a lot of heat but I think it's worth the time to check the connection and their resistance.