- Thread starter
- #41
Hi, sure! I'll give you some money for it too! Let me know how to send you the money. Thanks so much!
Active Suspension System Air Compressor (1 Viewer)
- Thread starter BJSeriesExpert
- Start date
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Just send me a Pm. They aren’t worth anything, happy to help out.
gaijin
GOLD Star
Just to be sure, the "other dealer" is a Toyota dealer, right? It is my understanding that only Toyota dealers have access to the high pressure (approx. 700psi) pump necessary to recharge the hydraulic fluid in the KDSS after replacing the valve assembly.
HTH
- Thread starter
- #44
Hello,
The other dealer is a Toyota dealer too. They have the tool to put in the KDSS valve. The dealer I originally went to didn't have the tool and was going to borrow the tool from this other dealer I'll be going to now. Do you have any idea how much fluid is needed? I bought 3 suspension fluids which the first dealer made me buy. Thank you for your input. Same goes for everyone.
bloc
SILVER Star
I’d have to dig into the manual for sure, but I think I remember it being more than the simple volume of the system since you effectively flush it a few times to get all the air out.
If the other dealer has the tool, chances are they have used it and know how to handle the system. I guess it could have been work on a 4Runner KDSS which is technically different but similar in operation.
- Thread starter
- #47
Hi All,
Out of curiosity and for my knowledge, why is a KDSS valve needed? Where does the fluid get pumped in the system? Coils? Shocks? I still am trying to piece things together but can't make things out. I mean what causes the lean when the valve is busted? Does it mean fluid isn't getting pumped on the driver side but what specific part is the fluid not getting to? Sorry for all the questions. Appreciate it guys!
Out of curiosity and for my knowledge, why is a KDSS valve needed? Where does the fluid get pumped in the system? Coils? Shocks? I still am trying to piece things together but can't make things out. I mean what causes the lean when the valve is busted? Does it mean fluid isn't getting pumped on the driver side but what specific part is the fluid not getting to? Sorry for all the questions. Appreciate it guys!
bloc
SILVER Star
The 30k foot view is you have a cylinder each on the front and rear that either locks that sway bar into acting like a normal sway bar, or "unlocks" it by hydraulically allowing one of the pivots to move freely. Those cylinders have hydraulic circuits that cross-link them.. so if you go into a turn and the truck leans right, they stay locked because both are moving the same way, but if you cross an obstacle diagonally, it is seen as articulation, aka the sway bars seeing opposing force, and lets those pivots move.
To accomplish this hydraulic cross-linking, and especially because the system is sealed with the cylinder shafts moving in and out of the system taking up space (displacing fluid), you need a valve body in the middle that can be used for filling/draining/bleeding the system, and a couple pressurized hydraulic accumulators that allow for the volume change in the system as those shafts move in and out of the cylinders.
When things get imbalanced in this system due to failure of a part, maybe the seal on the piston within one cylinder, too much pressure can be applied to the wrong part and now you've got a high pressure hydraulic cylinder cranking on a sway bar.. and the truck will lean.
Many people deal with "KDSS lean" after installing a suspension lift.. IMO the heart of this problem isn't actually the KDSS system, but suspension bushings not torqued at their new zero point, or springs incorrectly installed, or other issues.. and the 4x4 block of wood method to "fix it" is worse than a bandaid.. it is pre-loading the KDSS system in a way it wasn't designed to be used, massively increasing the loads when the vehicle is at rest.
But that's not what's going on with OP.. likely their system is so corroded that they've developed leaks or internal parts aren't moving/functioning as they should, and the only way to fix that is to throw expensive parts at it.
bloc
SILVER Star
Side note: I've had a desire for a while to do a detailed KDSS thread explaining everything about this system, but frankly can't handle creating the diagrams that are needed to visualize things. If you guys know anyone that can do this....
- Thread starter
- #50
Hi Bloc,
We can collaborate on this. I might have the softwares to create the diagrams you need for your thread.
Let me know, and thank you for the explanation.
gaijin
GOLD Star
Everything @bloc said, plus maybe a little more for the visual learners among us.
Here is a schematic of the Valve Body showing the two accumulators and the two shutter valves that are often talked about in relationship to "lean."
This is a totally passive hydraulic system, i.e. there are no pumps or electrical sensors anywhere in the system - just pressurized hydraulic fluid.
When the Shutter Valves are in their normal position - closed - the system acts just as @bloc explained.
When the Shutter Valves are opened, however, fluid is allowed to flow freely throughout the entire system and equalize pressure.
Barring any other mechanical problems, when the vehicle is on a level surface, and the KDSS valves are opened, pressure should equalize and the vehicle should be (or return to) level.
HTH
Here is a schematic of the Valve Body showing the two accumulators and the two shutter valves that are often talked about in relationship to "lean."
This is a totally passive hydraulic system, i.e. there are no pumps or electrical sensors anywhere in the system - just pressurized hydraulic fluid.
When the Shutter Valves are in their normal position - closed - the system acts just as @bloc explained.
When the Shutter Valves are opened, however, fluid is allowed to flow freely throughout the entire system and equalize pressure.
Barring any other mechanical problems, when the vehicle is on a level surface, and the KDSS valves are opened, pressure should equalize and the vehicle should be (or return to) level.
HTH
bloc
SILVER Star
Good call, I didn’t even think about the all-important shutter valves.
- Thread starter
- #54
Interesting you said that, I saw a 2015 LC200 being sold on Carmax, and the vehicle has the same lean as my 2013. I wonder if the lean is something Toyota needs to seriously address, starting with putting in a more robust system i.e. rust resistant parts, sturdier parts as well.
Until explained above, i always thought that lean was part of life at some point for most SUV. Personally, i don’t care about the lean because it does not affect performance/handling.......unless it is due to what you’re experiencing with the rusted/failed parts. I doubt Toyota will ever address the lean because it does not affect anything other than aesthetics. (Again, rusted & failed parts don’t count.)
Hey, for me and my simple mind, as long as it is within factory specs and does not endanger my family, i am good. But that is why i don’t modify my cars much.
