gxman1

Hello All!

I have been out of this board for a while. I have a problem and looking for help. In the past I read lots of thread on the spring conversion for the rear struts.
Anyway, here are the issue:

1. In my Driveway, many times I notice my GX in the rear is sagging. I measured it from the center of the wheel up . when it appears normal it is 21". When it is sagging it measures 18".
So there is 3" difference.

What is causing this, I know some will say it maybe a airbag leak. I dont think thats the case and I MAYBE wrong. Because, when I park the car with with no sag at night and the height is 21" it stays like that in the morning.

PLEASE HELP, also, I know there are lots of idea of doing a change over to regular struts. What is the best method out there?

Many thanks:

BradTank

Usually it starts out intermittently sagging, then it just goes out completely. At least that's what happened with mine.

So if you come out to the car and it's sagging in the rear, I wouldn't wait any longer, replace them. I decided to do a "wait and see" because it only happened occasionally, and it went out completely on a road trip with the rear bouncing like a stagecoach.

In my opinion, it's a part that is simply going to go out eventually on all of them, almost like tires, they're rubber and they wear out.

Do a search and see all the options. The GX was my wife's and we needed it on the road ASAP so we just went the dealer route of replacing the rear bags rather than ordering a kit and me installing it. Out the door it was around $800 for parts and labor to replace the rear bags. If it was my car, I would have gotten a steel coil kit for around half that and been done with the silly air ride.

gxman1

Thanks Brad,

Update: trying to troubleshoot. I stated the car last night, and raised the car to HI position and measured it, it is at 23" at HI point. This morning same 23". This is an indication the airbag is not leaking, am I correct?

tz693

I would say it most likely to be the height sensor intermittent.

ALAN553

There were many nights when I came back in the morning and there was no sag and then at another time it would. It's rubber, depending on how inflated or deflated it is, the hole may or may not open...could just be a pin hole....if it cycles thought the settings correctly, than height sensors are probably working. Go through hundreds of post here, the bags are made of rubber and they are under the truck....they leak eventually. You can wait until the reservoir solenoid burns out too from constantly adjusting the height due to leak, the truck will be left just sitting on the bump stops and you can be in the middle of nowhere..

BradTank

Not necessarily, even though you would think an airbag leak would leak air all the time, for whatever reason, it doesn't. Mine would be fine one day, the next I would come out and see it would be sagging slightly. I think the "holes" started out being really small and certain factors like the temperature can make them deflate much quicker.

This was my experience as well.

I'm not saying you should throw parts at it, you want to diagnose it correctly, but I think it's pretty likely if the rear air bags are original and they start sagging, they probably need replacement.

Ali SC3

iTrader: (10)

I thought If it's sagging in the morning even 1 time then it's the bags. My understanding was the car does not inflate based off the sensor until you put the key in, so if it's the sensor it would go whacky when you put the key in.. But I could be wrong haven't had it happen yet.

ALAN553

If you manually put it to the high position when you park, the hole in the rubber probably closes, as the bag collapses ever so slightly, the rubber folds and the hole opened up...its a 2003 right? Get underneath and take a good look, the rubber must be dried cracked and splot.

gxman1

Alan... I read many of your post on the 13 pages thread before posting a new thread. I know youre dealer change the parts and that didnt fix the issue. It was you who discovered the leak when vacummin the back. By the way did the airbag replacement fixed your GX problem?

Brad, that for the PM, and the posts here, I am asking all these questions, since Alan and other threw lots of money and the dealer didnt diagnose properly.

Another data point:
I just drove home and saw the car was bit low, I started the car and and hit the switch to L position, guess what the car went up an inch instead of going lower.

ALAN553

They replaced reservoir first, that did not fix it, I found the pin hole. I heard the leak one day, got underneath and could feel the air. They go by computer codes...its like bad medicine, not listening, maybe that was bad too but it didn't fix the problem. They did not charge me labor for the air bags replacements. They detailed the truck no charge. I replaced the height sensors just because. .....but it was the leak. I chose to keep the truck stock rather that switch to coils.

gxman1

ANOTHER UPDATE - Getting closer.

Last night, when I pulled into the drive way, the rear was low. I stated the engine and heard the pump turn on and leveled the rear.

After 1 hour I came out an saw the rear go down again, I started the car and it pumped it self back to normal.

This morning, I checked again and it was low, I started the truck and heard the pump and it leveled again.


Please correct me of the following assumptions.
1. It is airbags.
2. I am curious, if one airbag is leaking why both side is sagging, why not only one side, it is highly unlikely both side will leak simultaneously.
3. Or do you think the leak is in the line? Any diagram or procedure how I can check all this before I attempt to go under the back of the truck?

ALAN553

close?? LOL, it will come to you eventually. wait until it drops on the bump stops while you are driving on the highway...computer probably detects error codes and cant keep only one side up...

gxman1

Alan,

I hope it wont come to that, that is the only reason I am monitoring daily. I will get it fixed or do a conversion. I just dont want to rush and go thru what you went thru, dealer throwing parts.

Car is OFF and parked, I don't think the computer has anything to do with sagging, it is the leak, but the question is why both side drops while engine off , and since the engine is off it wont be self leveling ,,I think.

Did your both side sagged since you actually saw the leak in the boots. or one side?

I am thinking it is in the lines somewhere letting the air out of the bags.

Ali SC3

iTrader: (10)

I think you are trying really hard to find a way for it to not be the airbags, the only problem is it is at least one of the airbags. The reason both sides sag is that they are connected together at the compressor in a special way, where when one looses pressure, the other side does too via the same leak to lower the car down safely to the axle and rest on the bump stops. you would not want one side up on normal and the other side sitting down on low as you drive along, the engineers decided this would be more dangerous than de-inflating both bags when there is a leak in the system, so they deesigned it to deflate both sides when there is a leak so when the system encounters a fault it will lower both sides onto the bumpstops, and not cause you to swerve off the road or into oncoming traffic when you loose a bag while driving and the other side stays inflated you would have literally less than half the chance of keeping the car straight and bringing that thing to a stop safely.

lines generally do not leak but it is a possibility. the only way I would think it is that is if you tried to remove it improperly without the special service tool and damaged it, but out of the blue its much more likely to be a bag then an air line.

gxman1

Thanks Ali,

What a wonderful explanation..Amazing.

I do want it to be something so I can get it fixed. Now I understand the concept of both side deflating. I need to figure out which bag, or change both.

Good news is Lexus dealership is selling for $160 per bag. I am not sure if I can change it myself, since you mentioned special tools or I need to bring to lexus, again troubleshoot which bag right or left.