Air Suspension not working right

SUBYDAZZ · Post by **SUBYDAZZ** » Wed Jun 18, 2008 9:51 am

In an almost-last-ditch attempt to sort out some issues I'm having with my beloved Air Suspension system in the Liberty, I am whacking the details up here as well as what I have done so far. Feel free to assist if you can*

History:

Noticed that the suspension would not go into "Hi" mode, then ride in front was rough, losing pressure, fault code kept flashing up on switch after about 10 or more minutes driving

Self-diagnosed faults in the system to codes 7, 8 & 9. Codes 7 & 8 are rear solenoid valve output continues for 10 minutes and 9 is the compressor relay output continues for 10 minutes.

Couldn't seem to find any leaks in the system, so took it to Subaru how had trouble getting the system to charge and came up with "Replace Compressor" diagnosis.

Went for a 2nd hand compressor from the wreckers at first (ouch!), and all that seemed to happen is that I lost all the air out of my front struts, but back ones remained on a relatively high setting.

Then went for new genuine compressor (ouch, ouch!), and bingo, no difference.

Noticed that at least the front solenoids were not opening when height control set to high, manually opened them with +12V into solenoid connectors and front struts raised quickly to very high setting (while compressor was running). Also noticed solenoids not opening to release air when height control set back to normal. At least I can drive it a bit now.

Tried removing fuse, disconnecting battery and resetting Engine ECU in a vain attempt to reboot the suspension control unit or reset it. Since is a separate unit I don't this would work anyway. Codes in suspension ECU cleared (as expected), same ones return after driving for a while.

Replaced Control unit with wreckers number (ouch!) and no difference, tending to not want to try genuine new unit as the price I was quoted was $4154! Yes. I didn't think that was right either. An old Subaru parts CD I have had a completely different part number that was about 1/7th that price but didn't appear in dealers book / dodgy diagrams?

Running out of ideas now...

*comments about changing to conventional suspension will be ignored

Suby Roo · Post by **Suby Roo** » Wed Jun 18, 2008 10:01 am

Not a leaky air bag at all is it??

SUBYDAZZ · Post by **SUBYDAZZ** » Wed Jun 18, 2008 11:17 am

Nup, leaky airbags tend to leak air (had that before), these are staying up.

FROG · Post by **FROG** » Wed Jun 18, 2008 12:48 pm

DAZZ
do you enter your vin on your old fast or just do it by model????
throw me your vin number
ill have a read of the workshop manual tonight if i get time
cheers
Andy

Faulty pressure switch
BLOCKED or leaking air line
compressor circuit breaker getting hot
faulty height conrol sensor

SUBYDAZZ · Post by **SUBYDAZZ** » Thu Jun 19, 2008 9:47 am

I enter my VIN.

VIN has been thrown in PM.

I have a pdf of the FSM for mine and have been going off that.

I think I have found at least part of the problem, my rear solenoids are both open circuit, i.e. dead. Apparently I can get newies from Japan in a few weeks. Wreckers are loath to separate them as they are on the rear struts unlike the fronts.

Kind of interested in how/why they failed now.

FROG · Post by **FROG** » Thu Jun 19, 2008 10:05 am

Pm Replied

chriSTIan · Post by **chriSTIan** » Fri Jun 20, 2008 9:52 pm

U can buy my wgn with fully operational air suspension...

SUBYDAZZ · Post by **SUBYDAZZ** » Fri Aug 01, 2008 6:14 pm

Well, to cut a long and drawn-out process down to what the actual problem was I will say here:

Both of my rear airbag strut's solenoid's black wires had broken. This renders the solenoids broken but the ECU can't tell if it is working or not, since they are normally closed type then the struts retained what air they had until I left it out when pulling them out and changing the solenoids. Since all solenoids in the system appear to be the same I replaced them with some others I acquired, and patched up the wiring.

Since the back struts couldn't get up or down then the fronts (which are second in line in the air suspension system sequence stayed put.

You can manually inflate the fronts fairly easily by applying compressed air into the line south of the front solenoids and then plugging the line back into the solenoid to stop the air leaking back out. Getting the appropriate height is a bit tricky though

Now apart from some small leaks near the compressor area everything is now A-OK

SUBYDAZZ · Post by **SUBYDAZZ** » Fri Aug 01, 2008 6:19 pm

Well, that was until about 4 days ago when the struts went down, the invisible air leak got bigger and the new compressor ($500+) appears to have carked it. I didn't really need a new one anyway (Thanks Subaru) as it wasn't the problem, but now glad I have it because I think I stuffed the other one trying to rebuild it.

Luckily, I think I have now narrowed down the problem to a shot Air Suspension Compressor Relay and have sourced a similar item for $10 ($50-something from Subaru) and am going to fit it shortly (fingers crossed)...

vincentvega · Post by **vincentvega** » Fri Aug 01, 2008 7:31 pm

hahaha that was an entertaining read dazz!

we could have sent you a 2" kit, and ne struts + springs ith that much money!!

SUBYDAZZ · Post by **SUBYDAZZ** » Fri Aug 01, 2008 8:09 pm

Please, don't remind me. I have an eye on a set of coil-overs with adjustable struts tops at the wreckers at the moment too, just in case...

New relay seems to work, just have to get it all back together with my eyes shut (about the 10th time now, like radiators in my last L-Series) to see if it is all going to work like magic again...

vincentvega · Post by **vincentvega** » Fri Aug 01, 2008 8:40 pm

its a shame i threw out all my airbag stuff. i really should have shipped it to you. only had 80k on it

Suberman · Post by **Suberman** » Sun Aug 03, 2008 11:10 am

SUBYDAZZ - Luckily, I think I have now narrowed down the problem to a shot Air Suspension Compressor Relay and have sourced a similar item for $10 ($50-something from Subaru) and am going to fit it shortly (fingers crossed)...

Hi SUBYDAZZ, did she look like this when you first had the problem?

She takes five minutes to come up after ignition. Goes completely flat at the front after about five hours. This began the day after the car had been on a hoist having a gas conversion. Still doing it.

SUBYDAZZ · Post by **SUBYDAZZ** » Sun Aug 03, 2008 11:28 am

Yes it looked like that when my rear solenoid's wires were broken.

But they way you describe it, it looks like it will be more of a leak in the front struts. If the rear solenoids are not working the fronts won't come up at all.

Your compressor will also be running more because of the leak. You probably won't be getting an error flash up on your button yet, unless you drive for long periods of time. If it takes about 5 hours to come down it is probably a fairly small leak and you mightn't hear it when the car is off. You can try to test for leaks with some really soapy water on the rubber of the struts but it's pretty hard to see if it is on the back of the strut as you face it.

What you may also find is that a build-up of dirt etc. on the diaphragm's
rolling surface (ie the metal of the struts that the rubber bit rolls over) which can cause small leaks, but doesn't mean your rubber is leaking. These need to be kept as clean as possible. Once all the air has leaked out of the struts (or by disconnecting the air lines) you can jack up the car so the wheels are off the ground (good luck as the bugger will be very low if you try to use a trolley jack) and the struts will be at their full extension which makes it a bit easier to see and clean.

Hope this helps. I must be somewhat of an air-suspension expert these days.

Oh, and by the way, now I have replaced the dead relay and whacked a few extra o-rings in at leaky joins mine is going like new

SUBYDAZZ · Post by **SUBYDAZZ** » Sun Aug 03, 2008 2:46 pm

Here's some pics of mine when there was almost no air left in the struts:

Not much daylight here, and no-go for trolley jacks:

No fingers will fit between tyre and guard:

Hmm, fronts are surprisingly high, must be some air left:

Fully Sik(sic) lowered Lib

Scrapes going into and out of my driveway

:

Suberman · Post by **Suberman** » Sun Aug 03, 2008 3:03 pm

What got me is how bouncy it rides with no shockers. Hit the smallest bump and you're bouncing like a 70's cadillac.

SUBYDAZZ · Post by **SUBYDAZZ** » Sun Aug 03, 2008 6:09 pm

Yes, it's not pleasant.

Relying on the oil in the strut to do the job of a spring tends to do that.

SUBYDAZZ · Post by **SUBYDAZZ** » Mon Sep 06, 2010 8:24 am

Hmmm, how come my pics aren't showing any more?