Active Suspension System Air Compressor

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Sep 14, 2019
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Ohio
Hi All,

My 2013 LC is sagging on the Drivers side front and rear. I took it to Toyota and they said that I need to replace the active suspension system air compressor. I'm confused because I see there are coil springs on the suspension, and can't understand why an air compressor is needed for the suspension? Toyota did advise that if replacing the compressor doesn't work, I'll need to replace the Steering Damper and the Rear Coil Damper, which would be another 3K for parts and labor on top of the 2K they are charging me to replace the air compressor.

Anyone have any idea why one side would sag and if the air compressor has anything to do with it? The car drives fine though just notices the sag on one side when it is parked.

Lastly, any idea what the steering damper (4887660022 - Steering Damper (Front). Cylinder, Stabilizer Control - Genuine Toyota Part) and the rear coil damper( 4888660022 - Coil Spring Damper (Rear) - Genuine Toyota Part) will do with the sagging problem? I honestly am having doubts with Toyota's diagnosis, because they are currently unable to replace the air compressor because they claim that they don't have the tool to do so, which they need to borrow from another dealer.

Appreciate your inputs.
 

RET2

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Hi All,

My 2013 LC is sagging on the Drivers side front and rear. I took it to Toyota and they said that I need to replace the active suspension system air compressor. I'm confused because I see there are coil springs on the suspension, and can't understand why an air compressor is needed for the suspension? Toyota did advise that if replacing the compressor doesn't work, I'll need to replace the Steering Damper and the Rear Coil Damper, which would be another 3K for parts and labor on top of the 2K they are charging me to replace the air compressor.

Anyone have any idea why one side would sag and if the air compressor has anything to do with it? The car drives fine though just notices the sag on one side when it is parked.

Lastly, any idea what the steering damper (4887660022 - Steering Damper (Front). Cylinder, Stabilizer Control - Genuine Toyota Part) and the rear coil damper( 4888660022 - Coil Spring Damper (Rear) - Genuine Toyota Part) will do with the sagging problem? I honestly am having doubts with Toyota's diagnosis, because they are currently unable to replace the air compressor because they claim that they don't have the tool to do so, which they need to borrow from another dealer.

Appreciate your inputs.
Parody thread? Are you sure you didn't go to a Lexus dealer? Run away from this (s) dealer
 
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Joined
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Search on these forums for "Correcting a KDSS lean".

This looks to be the "steering damper" part of the KDSS (hydraulic cylinder)
kdss2.jpg

Coil spring damper (rear) is the hydraulic cylinder in the rear.
 
Last edited:

Sandroad

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Ack! There is NO active air suspension on the Land Cruiser and there is NO air compressor on either the Land Cruiser or the LX570 (Lexus system is hydraulic). There is a passive KDSS on the Land Cruiser that can develop a lean, but there is no compressor to replace and correcting the lean normally requires no parts. It's possible the valve body of the KDSS is heavily rusted and replacing that probably does require them to borrow the tool and it's an expensive operation. I didn't look up those steering and suspension parts, but I doubt they are the problem unless broken. So, either you or the dealer is confused about what's going on and you need clarification before plunking down your money.
 

bloc

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How uneven is it side to side? I believe up to an inch of lean is allowed per the service manual. Beyond that you can try opening the valves and in some cases this will let the system balance and level out, in others it is a deeper problem with springs, suspension bushing neutral position, or other.

If your system has totally failed you could get a lean but you’d have a leak somewhere in the front or rear cylinders or maybe the control/accumulator stack in the middle of the vehicle.

As others have said, there is no air compressor, or compressor/pump of any type on a 2008-current landcruiser.
 

TeCKis300

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Same as @bloc . How much lean are we talking about? Unless I'm not understanding, the compressor is a red herring. It likely also has nothing to do with KDSS either, unless someone lifted their vehicle without following reset procedures. Don't let them send you down the path of a wild goose chase.

Since the beginning of time with SUVs and trucks, or vehicles with tall soft springs, there's been a tendency to lean over time. Once a lean starts, more weight is carried by the lower side, further exacerbating the lean. All springs will wear over time potentially developing a sag to against the weaker spring in the set.

What to do? It's why trim packers exist. 5 or 10mm springs spacers to be fitted to the sagging side to re-level the vehicle.

You're right that there is no air pump. There's also presumptions about "KDSS lean". KDSS's function is strictly as a on demand sway bar. Sway bars generally do not impart any twist or lean on the vehicle and will tend to keep it flat/neutral. Messing with the KDSS system to fix a lean is another misdirection.
 

afgman786

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Gainesville, VA
Hi All,

My 2013 LC is sagging on the Drivers side front and rear. I took it to Toyota and they said that I need to replace the active suspension system air compressor. I'm confused because I see there are coil springs on the suspension, and can't understand why an air compressor is needed for the suspension? Toyota did advise that if replacing the compressor doesn't work, I'll need to replace the Steering Damper and the Rear Coil Damper, which would be another 3K for parts and labor on top of the 2K they are charging me to replace the air compressor.

Anyone have any idea why one side would sag and if the air compressor has anything to do with it? The car drives fine though just notices the sag on one side when it is parked.

Lastly, any idea what the steering damper (4887660022 - Steering Damper (Front). Cylinder, Stabilizer Control - Genuine Toyota Part) and the rear coil damper( 4888660022 - Coil Spring Damper (Rear) - Genuine Toyota Part) will do with the sagging problem? I honestly am having doubts with Toyota's diagnosis, because they are currently unable to replace the air compressor because they claim that they don't have the tool to do so, which they need to borrow from another dealer.

Appreciate your inputs.
You mention THEY ARE charging you 2k... I really hope you haven't had them start doing anything to your LC, when they don't even know what they are talking about. I would run far far away from them for any work.
 
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Ohio
How uneven is it side to side? I believe up to an inch of lean is allowed per the service manual. Beyond that you can try opening the valves and in some cases this will let the system balance and level out, in others it is a deeper problem with springs, suspension bushing neutral position, or other.

If your system has totally failed you could get a lean but you’d have a leak somewhere in the front or rear cylinders or maybe the control/accumulator stack in the middle of the vehicle.

As others have said, there is no air compressor, or compressor/pump of any type on a 2008-current landcruiser.

Hi,

What valve are you talking about? Where do I find it? I have no knowledge beyond the BJ series of LCs and this one is really new and foreign to me. Thanks so much for your input!
 

TeCKis300

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Hi All,

I'm not positive I measured the lean right, but it's about an inch or so. Below is the part that Toyota made me buy.


I got it at the regular price though as sold by the dealer. I wish I knew better.

Looks like "air pump" is a misnomer and it is referring to the KDSS accumulator. They are throwing parts at a problem they don't understand.

1595971868843.png


As I said earlier, the whole KDSS lean, IMO is a not even a thing. It's misdirected understanding of how the system works. It's a passive decoupling sway bar that in itself should not impart lean unless a newly lifted suspension is installed and they did not let the system balance by opening the valves. The accumulator also itself does not impart lean. It is meant to balance and dampen front to rear suspension movements. Leaning is due weakening springs over time. Common to all 4x4s.
 
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bloc

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Hi,

What valve are you talking about? Where do I find it? I have no knowledge beyond the BJ series of LCs and this one is really new and foreign to me. Thanks so much for your input!
It has been covered here a lot and far better than I can do so search for “KDSS bolts” or screws. Of particular note: DO NOT OPEN THEM MORE THAN THREE FULL TURNS EACH. That can result in depressurization of the system and a repair bill from a dealer that likely won’t even have the tools so you’ll have to wait for them to acquire it.
 

afgman786

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Hi All,

I'm not positive I measured the lean right, but it's about an inch or so. Below is the part that Toyota made me buy.


I got it at the regular price though as sold by the dealer. I wish I knew better.

If they haven't started any work, return the part and stop there with them... it should take a day or 2 for that part to arrive anyways. If it was me I would cancel anything they are about to start before its too late. No need for you to pay soo much money for something that they don't need to do.
 
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Resized_2.jpg
this is the picture of the part they made me pay for. See the condition it's in. Unfortunately the part is unreturnable and they made me pay for it upfront. The part and suspension fluid they made me pay for is 1600. I might file a complaint and just take my LC to another dealer.
 

CharlieS

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Yeah, that KDSS valve is a goner. Mine was rusty, but yours is a boat anchor. If you ever need to loosen the valves (like for suspension work), you'll need that to be in much better condition. To other posters above, once they open the system, they need a special tool to recharge it (so I read here on 'mud). You're in for a doozy of a repair bill.
 
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If you are close to Noblesville, Indiana you might talk to Eric Sarjeant. Unless a fair amount was lost in translation, you are looking at being the guinea pig at the local dealer. To find competence, a 1000 miles is close.
 
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Thanks guys. I'm just so disappointed on how much rust there are on this LC. It's just 7 years old. I just got it from a Cadillac dealer. Even the rear frame has pretty bad rusts on it. I feel like the rust has messed up the suspension system pretty bad. I seriously doubt changing those dampers will do a thing, does anyone disagree with that?
 

CharlieS

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For a 200 in places where roads are salted in the winter, I think what you are seeing is fairly typical. The KDSS valve in particular is delivered with a milled bare steel surface, and seems to rust quickly. Areas like the rear crossmember seem to rust quickly as well. Frame welds also seem to corrode pretty quickly.

Disappointing? Yes. I think a lot of us wish Toyota would do something about it, but I don't see it happening. In the meantime, coat the new one with LPS3 or grease when you get it back.

Unsolicited 2 cents: don't replace your suspension with stock. Now is a perfect time to upgrade (once they replace that KDSS valve).
 
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That’s bad.

A little undercarriage care goes a long way in the winter....just wash the salt off once a week.

Find and have the entire under carriage coated with Fluid Film or equivalent.
 
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Thanks all for all the great inputs. I'm finding more information now that I'm aware it's called a KDSS Valve.

My additional question is, how do I address the lean on the driver side? No choice for me right now but to have the KDSS Valve replaced since it's really bad and I already bought the part. But will fixing it address the lean though? If not, what do I need to do with the suspension? Get new coils?
 

CharlieS

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Once you have a working kdss valve you can turn the two shutter valve screws (no more than 3 turns) and it should level out. There is also a procedure to drive one wheel up on a 4x4 while it equalizes, but that may not be necessary.
 

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