BT3100

You most likely have what I had. The passengers hose from the compressor to the shock has a hairline crack under the rubber cover at the bend of the frame. This hose leaks under the small rubber portion and you will not detect by spraying water. I found mine by removing the rubber section, replacing the hose, inflating the system then slightly bending the host at it's natural curves around the frame. I even tried to repair the hose as a replacement was $90 and took 2 weeks to come in. No luck on that. but here is a link to it.

https://www.lexuspartsoutlet.com/oem...RoCAIwQAvD_BwE

Lexus4321

Did you take apart & clean out the air control box in rear? There will be fine dust build-up in that valve box.

phamine

Okay.

So today I smoke tested the hard lines from the air tank to each of the air springs. I pulled off the rubber protectors as well.
No smoke seen so the spring and the hard lines are okay.

There wasn't a way to smoke test the valve body on the air tank for leaks. I did spray soapy water on the tank and no leak to be seen also.

I'm going to take your suggestion and take the valve body apart and see if there are seals are bad.

Lexus4321

The valves/seals are likely not bad, but overly dirty.

frhill

I have an 08 GX with 255K mileage. I took my GX into Lexus service in St. Louis back in October to look at my leak problem. It seemed 2 out of 10 drives after sitting overnight the next morning the rear was sitting on the bump stops. They had it for a week and found no leaks. Now it seems that 7 out of 10 drives I find it resting on the bump stops either over night or two or within an hour. It’s an intermittent problem. What’s interesting is I drove the GX a week ago Saturday and the air held for 6 days. Took it out for lunch on Friday and within an hour it’s on the bump stops;



I will be traveling mid May to move my son home from college (Williamsburg , VA) - 1600 miles round trip from St. Louis. Pulling a large trailer for half the trip. I do not want to risk a complete failure - being broke down on Interstate 64 in West Virginia with a trailer is not my idea of a good time.



I notice another Lexus dealer in St. Louis had 2 luxury GX460s @ 70k MSRP. I thought, screw it, I’ll buy new. So last Friday I drove to the dealership. Only when I got there, they sold one and the other was on the way to be delivered. They were selling for MSRP and I could get in line to buy the other by putting $1000 down. It’s interesting they did have any 2022 GX460s on their lot. Not one.



Well I thought. I’m here, I leave my GX with their service department. On Saturday they called me and told me they checked the system and found no leaks. They said the bags look great. They think it’s either the valves or ride height sensors. To replace valves and tank is $4000 (only $800 is labor). I’m actually ok with that price because if I were to trade in my GX on a new one, that 4 grand would be 4 months of payments on the new GX. I’m not interested in going to a conventional set up; And my son got into Texas A&M grad school; Hence I’ll be moving him to Texas and in two years to Washington DC. He’s focus is on National Security with an emphasis on China. So I would keep the GX for at least 2 more years.



Anyhow; I’m wondering, should I just have them replace valves and sensors. They really don’t want to do anything unless they can positively diagnose. Seems like the sensors would require the vehicle to be on to work? But maybe I’m wrong. I could see a valve getting stuck open after shutting the engine off. The problem is; they have replaced a lot of air bags on GXs but never other components of the air system. They have GXs they’ve serviced that have over 500k miles and have only seen issues with the bags.



What do you guys think - replace valves and sensors?

lexo98

iTrader: (2)

Not familiar with these suspensions but where do the valves dump out the air? If a valve is sticking the air will be coming from there

chiph9

That's a lot of money for a "maybe". Ask them if they had checked the coil resistance of the valve solenoids. And if they'd applied power to them and listened to see if the valves actuated crisply. Looks like you can't buy the valve body separately - it comes with the tank (P/N 48930-60020, list price is $1100 or $600-ish from Amayama)

If the tank has water in it, ask about replacing the dehydrator + filter ($380, $40)

I'm with you. A few thousand on repairs vs. $1k a month payment for 4-5 years? I'll repair.

I recall someone saying (here or on Reddit) that their dealer offered them an even trade - their slightly used 2021 for a brand new 2022. Turned out the dealer was not allowed to mark up new vehicles but *could* on used vehicles. So the sales department was calling everyone they had sold a GX to the previous year and offering them this deal.

Chip H.

IanB2

The rear height sensors can't contribute to your airbags leaking down, they are only involved in setting the target height for the rear suspension, to shut off the air compressor once it's reached that height while airing up.

As for the valves and tank, that's a lot of money to throw at it, but it's not my money, and I also agree with "fix rather than replace" mentality. Given the air bags are already new, and yourself and 2 dealerships have now checked the hard and soft lines for leaks, it makes sense that the problem would lie somewhere in the valves/tank assembly...it's all that's left!

frhill

Gentleman, thank you for your expert opinions. The parts came in TODAY for the new valves, tank, etc. And my GX finally dropped for them. They were able to find the leaky bag. Apparently, the rear of the vehicle can compress the bags in a way where they don’t leak. So, instead of a $4000 job, I was charged $1600 for bag replacements. That was close as I was ready to pull the trigger for the more expensive repair - and I would have been back because of the leaky bag. Whew. Glad to have the old rig back and turn in the loaner RX350 - they really should have running boards - hard to step in and out of. Best, Fred

ALAN553

it's always the bags and finding the leak to prove it seems to be the major theme on message boards. It's thick rubber...when fully inflated...pin holes close up.

IanB2

So you had one of your Arnott replacement airbags leaking from new then?

Glad they got you sorted out and it wasn't the more expensive repair!

frhill

Actually, I highjacked this thread. My airbags were original. So I hope to get 250K out of them that would put my odometer over half million miles

IanB2

Ya, I got you mixed up with the OP. Glad you're sorted out too though!

Lexus4321

The bubble solutions used in HVAC work is an ez way to find pinhole leaks.

AFA

Hi All,

My 2008 Lexus GX 470 has 163,000 miles on it. I would like to convert the air suspension to a traditional spring/coil suspension. I took my vehicle to the Lexus dealer and they said they would not perform such a service. I have found a local shop that is willing to do the work.

I am curious to know if you have a recommendation about aftermarket parts/kits that work great for a GX and your experience with it. Also, I have heard that eliminating the air suspension could trigger a light on the dashboard. Have you had any experience with it? If so, what did you do to eliminate it?

Thanks,