Serious kdss problem

[Jeremy556]

OK, I was being a SA when I posted that, but seriously - fix it? Not so sure I'd do that. Let's just say you get lucky and do get it fixed right the first time, and for oh, what, $1,000?

There are 3 more of those cylinders left, right? Just sayin'.

Just 2, 1 front, 1 rear.

 

[Bama67]

As someone that recently joined the 4Runner crew with a KDSS model, this frightens me a bit. That is a VERY expensive fix.

But for the life of me, I cannot figure how this would be that hard of a fix. I don't know much about the KDSS system, but isn't it just basically a closed loop with two cylinders that just work passively? One goes up, other goes down?

These KDSS 4runners are rare, but not exceedingly so, there has got to be wrecked ones out there, and I would think the cylinders off of one would be really cheap.

It might take a bit of research to find the part, and also to figure out how to bleed it, but should be easy enough with the right tool.

Also, I wonder if someone could figure out the viscosity or oil ratings of the KDSS fluid and cross reference it to a regular (economical) hydraulic fluid? $30 in fluid vs $300. I am sure Toyota is just using something else rebranded and charging 10x for it. Probably.

This thread is pretty important and could be a great source of info for us KDSS owners that might have issues down the road.

Good luck OP no matter what you choose to do!

 

[apollo]

Not a real engineer, for the record. IT guy with engineer in job title, kinda like a custodial or sanitation engineer. :nerd:

haha...yet demonstrably knowledgeable, and friendly edit: (enough) to help people with questions relating to your knowledge...just glad to see your IT title includes engineer instead of architect

 

[Jeremy556]

But for the life of me, I cannot figure how this would be that hard of a fix. I don't know much about the KDSS system, but isn't it just basically a closed loop with two cylinders that just work passively? One goes up, other goes down?

These KDSS 4runners are rare, but not exceedingly so, there has got to be wrecked ones out there, and I would think the cylinders off of one would be really cheap.

It might take a bit of research to find the part, and also to figure out how to bleed it, but should be easy enough with the right tool.

Also, I wonder if someone could figure out the viscosity or oil ratings of the KDSS fluid and cross reference it to a regular (economical) hydraulic fluid? $30 in fluid vs $300. I am sure Toyota is just using something else rebranded and charging 10x for it. Probably.

Not passive, there is an ECU that controls valves connecting the upper and lower chambers of the KDSS pistons, based on input from the wheel speed, steering angle and yaw rate sensors.

The high pressure pump is available for $450 here
Toyota Lexus Kdss Fluid Pump Bleeder.*otc 00002-12000-01, Tmc 09760-60020 - New Other (see Details) for sale in Douglasville, Georgia | Vehicles-Classifieds.com
and the procedure is here
GSIC - Global Service Information Center

 

[BCtrail]

As someone that recently joined the 4Runner crew with a KDSS model, this frightens me a bit. That is a VERY expensive fix.

But for the life of me, I cannot figure how this would be that hard of a fix. I don't know much about the KDSS system, but isn't it just basically a closed loop with two cylinders that just work passively? One goes up, other goes down?

These KDSS 4runners are rare, but not exceedingly so, there has got to be wrecked ones out there, and I would think the cylinders off of one would be really cheap.

It might take a bit of research to find the part, and also to figure out how to bleed it, but should be easy enough with the right tool.

Also, I wonder if someone could figure out the viscosity or oil ratings of the KDSS fluid and cross reference it to a regular (economical) hydraulic fluid? $30 in fluid vs $300. I am sure Toyota is just using something else rebranded and charging 10x for it. Probably.

This thread is pretty important and could be a great source of info for us KDSS owners that might have issues down the road.

Good luck OP no matter what you choose to do!

Hi bama67. When i first started to deal with this problem 3 months ago i knew nothing
About kdss now im a pro. The kdss system is a high pressure system that works with a hydralic fluid and a high pressure gas in the same cylinder one ion the front drivers side
Swaybar and one in the back. The system is working continuously to stabilize the ride and vibration. The cylinder itself is 1639$ US and toyota charges 2900$cnd. Even with the low dollar its still cheaper to step across the line and buy it. The dealer has estimated 1100$ for install and fluids in vancouver bc. Now the tool i have asked every toyota and most lexus dealers if they have the gauge and machine to charge and discharge the high pressure system and only one in surrey has it. They all say at first its suppose to be in service but none had it. They claim its 2000$ for it and with trails being rare there not willing to put out the money

 

[BCtrail]

[MENTION=119149]BCtrail[/MENTION] I just pm'd a fellow member and engineer my thoughts on helping you out a bit. If he concurs I will post a possible alternate method that could be a much cheaper fix. I will update this post soon.

Update:
Alright, just went through this with [MENTION=78273]Jeremy556[/MENTION] and we both agree there is an alternate way to fix your problem.
First of all, do this at your own risk! This is what I would do in your situation and if you don't feel comfortable with it then by all means work it out with Toyota.

The TE KDSS system is not magic nor are there any components or systems that are not in use on other types of equipment.

If this were me with your problem:
1. Print out all applicable data on the KDSS system.
2. Drive your truck to a local hydraulics shop armed with that information and ask them for an estimate on repairing the KDSS cylinder and recharging the hydraulic side of the circuit. I checked and you have several shops close by. If the KDSS cylinder is able to be disassembled then it would be short work for them to put in a new rod seal. If the shaft is galled or the cylinder is built to be a throw away then you will have to get a new one.
3. Depending on which way you go with the cylinder I would still a) buy the fluid from Toyota and b) take it to the hydraulics shop and let them bleed and fill your KDSS hydraulic system. Why? These guys do hydraulic machines all the time and your local Toyota garage never does. They will know what to do if you give them the procedure with the correct pressure settings.

Now, this is what I would do. You could save potentially $2K or more by doing it this way. If you have to buy a new KDSS cylinder then that cuts back on your savings but a decent hydraulics shop already has the tooling they just don't have the procedure or the fluid.

Again, this is an alternate way to approach this fix. If you are uncomfortable with any part of it then by all means take it to the Toyota garage and let them do the whole thing. Good luck.

Thanks for the info. There is no way in the world i am mechanically enclined
Im a carpenter if the kdss was made of wood i could fix it but iwill leave it to
The dealer im suppose to trust to get it right. I have found a dealer that has the
Sst and i will purchase the cylinder in bellingham just across the border. Thanks for
Figuring it all out i find it fascinating but im not able to do it

 

[BCtrail]

These are just simple hydraulic pistons right? Is there any reason you can't just source a replacement piston from surplus center or elsewhere and have a machine shop weld on the proper ends from your existing one?

I don't know that it's worth the effort to save very little, but is there some reason it's not doable?

Hey jetboy. The kdss cylinders are a high pressure system that runs hydraulic fluid and high pressure gas in the same cylinder. They need a sst that very few have but very necessary to charge and dischsrge the system safely. The overall project will cost me 3000$ canadian
Thats an estimate i just found a dealer today that has the machine. Now to order the part. A few weeks yet till i get it done. Its a bery hitec system that does work awesome

 

[Engineer]

Hey jetboy. The kdss cylinders are a high pressure system that runs hydraulic fluid and high pressure gas in the same cylinder. They need a sst that very few have but very necessary to charge and dischsrge the system safely. The overall project will cost me 3000$ canadian
Thats an estimate i just found a dealer today that has the machine. Now to order the part. A few weeks yet till i get it done. Its a bery hitec system that does work awesome

I don't think there is any gas, just fluid at around 435psi in the system (Edit: See 1Engineers post below, there is indeed nitrogen gas in the system). Anyhow thats criminal what they are charging you. I understand it is what it is but wow. I would consider a run to the States for the tool and part which sounds like would only run you 1500. Any ways what are the chances you would mind saving the cylinder and maybe doing a tear down/photos of it? I think what others mentioned that IF this is a rebuildable cylinder this job could be done for much much less. Maybe some other member in the great north would be willing to do it for you if you just gave them the cylinder. Just a thought

 

[1engineer]

I don't think there is any gas, just fluid at around 435psi in the system. Anyhow thats criminal what they are charging you. I understand it is what it is but wow. I would consider a run to the States for the tool and part which sounds like would only run you 1500. Any ways what are the chances you would mind saving the cylinder and maybe doing a tear down/photos of it? I think what others mentioned that IF this is a rebuildable cylinder this job could be done for much much less. Maybe some other member in the great north would be willing to do it for you if you just gave them the cylinder. Just a thought

There are accumulators mounted back on the frame that are precharged with nitrogen. Usually the rule of thumb is two to one precharge to system pressure. There is no gas in the cylinder but there is in the accumulators. I understand the OP not wanting to take an alternative way to solve the issue as you really need to understand hydraulics before attempting to fix it.

 

[BlackWorksInc]

There are accumulators mounted back on the frame that are precharged with nitrogen. Usually the rule of thumb is two to one precharge to system pressure. There is no gas in the cylinder but there is in the accumulators. I understand the OP not wanting to take an alternative way to solve the issue as you really need to understand hydraulics before attempting to fix it.

On the subject it reminds me of the LX470 suspension I did for my step-dad. Needed 4 new nitrogen bulbs and the super secret suspension fluid. Was like $2300 (at my technician discount) just for the parts. I could easily see a job like this being in the $4000 range or more.

:roadkill:

 

[Engineer]

It looks like the KDSS system takes a max of 6L of Toyota AHC SUSPENSION FLUID - TOYOTA (08886-01805) which is around $30 for 2.5L so 90$ would get you all you need (the fluid, not the service tool or cylinder). It seems this is the same fluid that is used on the LX height adjustable suspsension

 

[BlackWorksInc]

It looks like the KDSS system takes a max of 6L of Toyota AHC SUSPENSION FLUID - TOYOTA (08886-01805) which is around $30 for 2.5L so 90$ would get you all you need (the fluid, not the service tool or cylinder). It seems this is the same fluid that is used on the LX height adjustable suspsension

Neat, it got cheaper; used to be like $50~60 just for 2.5L last time I needed it a few years ago. Its pink by the way, so don't confuse it with the coolant. :nerd:

 

[BCtrail]

Neat, it got cheaper; used to be like $50~60 just for 2.5L last time I needed it a few years ago. Its pink by the way, so don't confuse it with the coolant. :nerd:

Toyota told me it is 63$ a bottle for the fluid needing 6.5 litres to fill
I will keep the cylinder if anybody might want it

 

[1engineer]

On the subject it reminds me of the LX470 suspension I did for my step-dad. Needed 4 new nitrogen bulbs and the super secret suspension fluid. Was like $2300 (at my technician discount) just for the parts. I could easily see a job like this being in the $4000 range or more.

:roadkill:

In the real world (not Toyota) those are called bladder style accumulators. They are very common in the hydraulics world and they are not cheap either. Actually the piston style accumulators are even more expensive.

 

[Jetboy]

Does anyone have a description of the reset/bleed process? After looking over what the SST is, my guess is that this *could* be done at home. I'm not necessarily suggesting it should be done by most people, but some of use might want to at some point. The SST is just a hydraulic pump and bleed kit in a fancy metal box. Nothing terribly exciting.

Looks like you could replicate the bleed kit SST for about $3-400.

It is comprised of five pieces:

The Manifold/pressure guage:
1 4way manifold
1 10mpa pressure guage
2 12" flex hydraulic lines
2 Hydraulic quick release female fittings
1 Quick Release Male fitting

The Pump:
Foot Hydraulic Pump w/ 1 female quick release hydraulic fitting

24" Hose connecting pump to manifold.

and 2 bleed cups and hoses.

To build a home version I think a hydrostatic test pump $100 plus a 4 way manifold $30, some hoses $50, some couplers $80 and a pressure guage $25 plus maybe another $100 in budget because these are just random choices, I don't know for certain what fittings are used by Toyota for example. Anyway, the price from Toyota to build a bleed kit isn't all that far out of reason, but it possibly could be replicated cheaper if you really wanted to do it yourself.

The process appears to be just bleeding the system like you would brakes and then adding some pressure. The nitrogen dampers probably don't need to be messed with unless the bladder fails or something unusual like that.

 

[Jeremy556]

Does anyone have a description of the reset/bleed process? After looking over what the SST is, my guess is that this *could* be done at home. I'm not necessarily suggesting it should be done by most people, but some of use might want to at some point.

Looks like you could replicate the bleed kit SST for about $3-400.

The high pressure pump is available for $450 here
Toyota Lexus Kdss Fluid Pump Bleeder.*otc 00002-12000-01, Tmc 09760-60020 - New Other (see Details) for sale in Douglasville, Georgia | Vehicles-Classifieds.com
and the procedure is here
GSIC - Global Service Information Center

....

 

[BlackWorksInc]

In the real world (not Toyota) those are called bladder style accumulators. They are very common in the hydraulics world and they are not cheap either. Actually the piston style accumulators are even more expensive.

I made that name up because I couldn't remember what Toyota calls them. But yeah, those things were something like $500 a pop at my cost.

 

[BCtrail]

Neat, it got cheaper; used to be like $50~60 just for 2.5L last time I needed it a few years ago. Its pink by the way, so don't confuse it with the coolant. :nerd:

Hey BlackWorks inc do you think this cylinder is rebuildable
Then i could have a spare.

 

[BlackWorksInc]

I suppose? There's nothing in TIS about rebuilding the unit. But I am sure if you find a savvy hydraulic shop they could do it.

 

[BCtrail]

Hi all this is my first post ive been a long time lurker and have joined now to seek the advice of the people that know 4runners. I live in Vancouver Canada own a 2010 TE and love it. I started noticing clanging in the front end and shortly there after clanging in the rear. I took it to my Toyota dealer were they determined the front cylinder on my kdss was leaking and had depressurized the system. The cost of a new cylinder is 2995.00$ and the labour and fluids an adittional 1400.00$. Wow also there will be 6 to 9 weeks wait for part and tool they dont have. I am working with a susspension shop and there researching out how to remove the system and put in new suspension. Does anybody have any thoughts ideas suggestions on this expensive pronlem

Conclusion,finally found a toyota dealer with the machine, took it in yesterday,they hooked it up and the pressure was slightly low but not depressurized completely like my toyota dealer told me it was. They also told me (and showed me) that the front cylinder was not leaking and didnt need replacing unlike my dealer who said 3000$ for the part. The computer had a couple codes pointing to the electrical connection on the main valve on the side of the frame,when he removed the cover it was full of mud and the connection full of water,he cleaned and dried then water proofed the connection clearing the codes and bringing the pressure back to normal and it now is back up again. The clunking has stopped and the kdss light no longer flashing.
For a grand total of 150$.