Jump to content
Ultimate Subaru Message Board

Attempting to diagnose self level susp issue


Recommended Posts

Hey all, new to this place but not new to the Subaru comunity. I was a prior 2000 2.5RS owner, had to sell my baby to go back to school...but recently aquired a 1986 GL-10 XT 5 speed turbo 4WD. WOO HOO! I'm loving this car, got it at a bargin...but have one major issue...

 

The lady I bought it from smacked into something in the front drivers blinker area...destroying the blinker and bending the fender. I've got a replacement fender and blinker though, which is a good thing.

 

The bad news is that the air suspension isn't working at all. On the dash I'm getting the "high" blinking and the car rides like it has no damping whatsoever. It's pretty awful.

 

I got the fender off to take a look in there, and everything is connected.

 

What I'm trying to figure out is A) what is wrong and B) what I can do to fix it. Of course I can just go to a junkyard and get coilovers...but honestly, I would like to get this fancy stuff working again.

 

I removed the air compressor and it looks fine. Plugged it back into the car and turned it on (without the air lines attached) and there was nuthin...no air coming out.

 

Any thoughts/ideas/suggestions on what to do to troubleshoot this?

 

Thanks in advance!

Link to comment
Share on other sites

Most likely one of the sensors inside the shock itself. When this doesnt work the compressor wont run. I had the same problem on my XT6 and when I replaced the front with Legacy struts the stupid compressor started working again :banghead: You will need to replace the air shock on that side to fix it(if you can find one). And the price new is like $150ea.

Link to comment
Share on other sites

Most likely one of the sensors inside the shock itself. When this doesnt work the compressor wont run. I had the same problem on my XT6 and when I replaced the front with Legacy struts the stupid compressor started working again :banghead: You will need to replace the air shock on that side to fix it(if you can find one). And the price new is like $150ea.

Argh!! I was hoping it wouldn't end up being an "inside the strut" kinda fix. Looks like my new toy is gonna be sitting in the driveway a bit longer.

 

I just wonder if it is going to be worth doing all this troubleshooting to get a rather complicated (but cool) system working...or just swap "normal" suspension in.

 

Looks like it's gonna be a big 'ol junkyard run!

Link to comment
Share on other sites

Start by checking the compressor.

 

The compressor relay is mounted to the driver's strut tower (in the engine compartment). It's covered with a rubber boot. Pull the connector off the relay. You'll see two thick wires and two thin wires. Using a piece of wire, connect the two thick wires together. If the compressor now runs (even with the ignition switch off), the compressor and its power supply are OK. If the compressor doesn't run, you might just have a blown fuse.

 

Search for other posts by me. One of them goes into great detail on checking the air suspension. Search, and you shall find.

Link to comment
Share on other sites

Start by checking the compressor.

 

The compressor relay is mounted to the driver's strut tower (in the engine compartment). It's covered with a rubber boot. Pull the connector off the relay. You'll see two thick wires and two thin wires. Using a piece of wire, connect the two thick wires together. If the compressor now runs (even with the ignition switch off), the compressor and its power supply are OK. If the compressor doesn't run, you might just have a blown fuse.

 

Search for other posts by me. One of them goes into great detail on checking the air suspension. Search, and you shall find.

Holy CARP! I found the relay...it was totally covered in goo underneath where the wires run into it. I bridged the two thick wire and low and behold, the compressor went on! That is a good sign I hope....

 

I'm now searching through your posts to see what other info I can gleam.

 

LOL, I'm starting to miss my Leda coilovers from my RS

 

Oh yeah....THANKS!

Link to comment
Share on other sites

the air suspension isn't all that difficult to maintain. you need to be able to source parts and do some work. but once you get it working and understand it, it's not that bad. don't let it seem confusing - it's only a computer that uses the solenoids, compressor and tank to fill up the struts. not really that complicated. i put off working on it for too long, thinking it was difficult.

 

make sure the compressor and the solenoids for each strut work. the solenoids are likely in the engine bay right next to the top of the struts in the front and connected to the struts in the rear (i have only worked on XT6's so im not 100 percent sure of the XT).

 

buy a bunch of o-rings and replace ALL of them. at each air line fitting you'll find o-rings. at the air tank, compressor, solenoids, replace them all. these are common leakage points. if your compressor is bad, it's likely because it ran too long because of an exisiting leak. the orings aren't hard to replace but do not break the air lines fittings. they are fragile. a piece of tubing with a slit cut down the length of it so you can wrap it around the air line will slide down and pry all the fingers apart if you can find the right sized tubing at a hardware store. imagine a short piece of straw cut down the length so you can slide it over the air line....slide it down and it will pry the fingers open without damaging them. now with that picture in your mind, find some better material than a plastic stray at the hardware store and you'll have an air line removal tool. or borrow/buy one from subaru.

 

if you want your struts to last and they have any age to them...pull them off and use some fittings from the parts store to extend them all the way with an air compressor. you'll see where the rubber air bag meets the metal lower portion of the strut. be sure to wire brush this really good, make is smooth and paint it with some type of very resilient paint. rust at this juncture is what ruins most struts. the rust builds up and will gradually break down the rubber where it meets the rusted metal portion of the lower strut. i've yet to have any struts leak air from anywhere else but this point where the rust forms. take care of that and your struts will last a long time.

 

best bet is to find a cheap source for parts and buy one of everything, that way you have it on hand just in case. you already checked the compressor, right? and yo'ure sure it wasn't putting out any air? again if your compressor is indeed bad, be sure to replace all of your o-rings and keep your eyese out for leaky struts - any leak will cause the compressor to cycle on all the time and shorten it's lifespan.

 

give 12 volts to each solenoid - you should hear them click open and close.

 

i'm not familiar with the relays so follow the instructions from others for that as i've never had issues with them.

 

now that i've said too much.....make sure your compressor does or does not work and we'll go from there. with the compressor off, be sure to remove all the old orings and replace them with new. also - apply grease to the new orings when you install them.

Link to comment
Share on other sites

I think I might have led you astray -- I'm active not only in the USMB, but also in the XT6 board. http://xt6.net/forum/

 

I think my air suspension posts can be found in the XT6 board.

 

Good luck. At least, you know that the compressor is working and that its power supply is good. You also know that the connections to the compressor are working. This leaves the control circuit.

Link to comment
Share on other sites

Great info from the XT6 guru's. They helped me trouble shoot my suspension, but I had to many things going bad and didnt want to spend alot of money to get it right again.

But I think we are forgetting that the car in question was damaged in the area of the compressor and air tank. I'm surprised the comp works after taking a hit, but theres definatly some damage done to some other components like the air tank, lines and probably the shock(s).

Link to comment
Share on other sites

I went through all the "air suspension" threads here...and on the XT6 board...and copied all the relvant info into one document. 10 pages with 2 diagrams! Yow.

 

I'm going to go through the whole system check each component as I go. Compressor, solenoids, lines, struts, and computer. I'm going to pull each strut out and clean 'em, replace all the o-rings (and grease them!) and we shall see what happens.

 

Damn I wish I didn't have to work today! Oh well...

 

Thanks again everyone here...I'll post up what happens.

Link to comment
Share on other sites

Well by bypassing the compressor relay I was able to get the compressor to kick on.

 

By bypassing the two front strut solenoids I was able to make 'em click open.

 

When I first start the car I can hear the compressor kick on briefly.

 

The air lines are in tact.

 

However, the bags are still not inflaiting.

 

The good news is that there are two PDF files that are EXTREMELY useful here...

http://endwrench.com/images/pdfs/AirSuspenFall01.pdf

http://endwrench.com/images/pdfs/AirSuspSumm01.pdf

One explains the whole system, the other goes through diagnostic testing.

 

It looks like Turbone is probably going to be right. The compressor works, the solenoids work. And the blinking light on the dash indicates that the "control unit is getting an impossible signal from the reed switches in one or more of the struts". What I need to do is isolate that as an issue. That means disconecting the height sensors in each strut one by one...turn off car, disconnect from first strut, turn on car. If light doesn't blink, that strut is bad. If light still blinks...turn off car, disconnect from second strut, turn on car. Rinse and repeat.

 

The "bump" didn't do a lot of damage to the car...just bent the bumper in and broke the blinker light housing. But...it could have been strong enough to damage that reed sensor.

 

We shall see!

 

And yes, it this is a complicated system, but it isn't impossible to understand...thankfully!

Link to comment
Share on other sites

SUCCESS!!!!

 

Disconnected the height sensor on the drivers side front strut...the one that was closest to the "accident". Light still stays on...so I'm bummed, thinking it'll be something else.

 

I think about quitting for the night...but hey, I can probably pull the plastic mud guard enough to get at that passenger front connection...pull it...turn on car, compressor kicks on! Light on dash goes away! WOO HOO! Plug drivers side back in...and light stays off, compressor still runs...AWESOME.

 

Well, mildly awesome. Looks like I'll need to source myself a passenger side front strut. But hey, at least I know it should work!

 

There is one remaining "issue" though. I still want to check all the air lines and make sure there are no leaks...that compressor was running quite a while and I hate the idea of burning it out as it tries to fill bags that have leaks :(

 

Thanks again everyone!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...