KDSS Stupid (1 Viewer)

[kcjaz]

Let me start by saying that I'm an idiot. I went to adjust the KDSS system by driving the high side up on a block to see if I could improve "the lean." My first shot (using a 1 1/2" block under the tire) made a 1/4" improvement on a 1" initial side to side difference. So, I decided to try a 3" block. As I went to tighten the KDSS valves, I somehow, without thinking, turned the screw counter clockwise continuing to loosen it until it blew out and oil went every where. I can't believe I really did that. But I did. For what's its worth it takes about 7 turns to remove the screws...

Have I damaged anything? Does a dealer have to refill the system or can any shop do that? Whats that going to cost me? Will driving it with no KDSS pressure hurt anything until I can get it fixed? I'll have to drive it to a shop somewhere like it current is.

 

[Union]

Sorry to hear about this happening! The dealer will need to get a special part to refill the system. From what I understand it is NOT the same one they use to fill the 4runner KDSS system. It will probably cost a fair bit of money. Try searching the forums.

 

[Markuson]

Sorry that happened...

Most dealers will have to obtain the special pressurizing tool from Toyota or another dealer in order to perform this repair. It is many hundreds of pressure #...so definitely not something shops can just do. I’d wager many (most?) dealers have never done it on a 200.

If your dealer says something like, “Oh ya, we can do that...” beware...as the service guy may not even realize what is required...

 

[kcjaz]

Thanks. I found an old thread from 2012 that was someone looking for a dealer who could do it. Was $500 then in SoCal. Awesome.

The really sad thing here is my “lean” wasn’t that bad and I will be getting my new BP-51 parts this week. There was no reason to level it now. I was just curious. Now I know how a dead cat feels.

 

[bloc]

I'd really like to get my hands on one of these tools and see how it works. As far as I know all it does is connect to the QD fittings behind the DS rocker panel.. and fill, and maybe flush the system. Obviously it needs the ability to hit the required ~400psi and force fluid in..

I should probably look into the FSM procedures...

 

[99Cruiser]

On the bright side the install of the BP51 should be much easier without the pressure. Get it filled after installing the suspension. I am sure when that pressure released you puckered up.

 

[supercarrera]

That's a bummer! Did the fluid spray all over you?

 

[kcjaz]

Actually the pressure release wasn’t as I would have thought. After the “spray” I had the 5mm Allan in my hand with the valve stuck to it. It wasn’t so much a picker as a sinking feeling realizing what had just happened.

I’m afraid to have the dealer fix the KDSS after the other shop puts on the BP51 Because if there is any issue with the KDSS, or suspension, the dealer will point at the aftermarket parts and the shop may point at the KDSS.

 

[kcjaz]

I'd really like to get my hands on one of these tools and see how it works. As far as I know all it does is connect to the QD fittings behind the DS rocker panel.. and fill, and maybe flush the system. Obviously it needs the ability to hit the required ~400psi and force fluid in..

I should probably look into the FSM procedures...

https://toyota.service-solutions.com/en-US/Pages/ItemDetail.aspx?Sku=00002-12000-01

it’s only $1475...

 

[cboyd]

regardless of the suspension, they’ll do it. I had a lot of KDSS issues after my lift and to have a rebleed done to get it leveled. $650. They did have to have a tech order the fluid and tool from the regional center

sorry dude.

 

[bloc]

regardless of the suspension, they’ll do it. I had a lot of KDSS issues after my lift and to have a rebleed done to get it leveled. $650. They did have to have a tech order the fluid and tool from the regional center

sorry dude.

What KDSS issues? Lean? And no issues before the lift?

 

[terdrocket]

For those messing with and scared of the KDSS valves -

When I installed my rear spring spacers, I had the rear frame on jack stands with the rear axle in full droop (or the best it could droop with KDSS closed).

With the valves fully closed, I jacked up one side of the rear axle. With the KDSS screws closed, you could feel the system fighting the axle twist. It wanted to lift the whole truck off of the jackstands rather than just one side of the axle. The opposite side of the axle was not allowed to drop, while I lifted one side.

I then opened one KDSS screw until the pressure shifted and opposite side the axle drooped fully. This was less than 3 turns. It was .5 to 2 turns, roughly.

I then cracked the other KDSS screw for good measure. It didn't seem to do anything futher.

I was happy with this technique, as I saw actual results. It's always odd opening the screws making sure you turned them enough, but scared to death that you will turn them too far, yet all the while nothing is visually happening during this proceedure.

I hope this helps.

 

[CharlieS]

What does backing out the "shutter valve" screws (only 2.0-3.5 mm, not removing them) for the upper chamber shutter valve and lower chamber shutter valve do inside that block?

Does it turn the whole thing into one big loop? Does it just effectively disable the left to right "balancing" so the anti-sway bars provide less resistance while installing the suspension? Also allowing all four corners to come to equilibrium eliminating lean?

I'm trying to understand why/how loosening only one of the shutter valve screws like terdrocket did, works...

Practically speaking I want to know for my suspension install, because I was able to get one of my shutter valve screws to move, and the other is still stuck (after over a week of Kroil dousing, scraping with picks, and snapping one hex bit so far).

I couldn't find the exact answer on a search, so apologies if this has been rehashed before.

I did find the following (and read a lot more), and learned a lot in the process:

Interesting video (150 series but same idea, I think):

And the first two minutes of this (previously posted by Markuson):

And a good written description here: 2013 200 mods and effect on KDSS and other features

 

[bjowett]

The main assembly part of the tool is a simple and widely available air over hydraulic foot pedal activated pump. Applications are normally presses and small lifts. They can be purchased for as little as $150 - $200.... though who knows what you may get at that price point. The more relatively difficult part is gathering up all the hoses, gauges, and adapters.

 

[bloc]

What does backing out the "shutter valve" screws (only 2.0-3.5 mm, not removing them) for the upper shutter valve and lower shutter valve do inside that block?

Does it turn the whole thing into one big loop? Does it just effectively disable the left to right "balancing" so the anti-sway bars provide less resistance while installing the suspension? Also allowing all four corners to come to equilibrium eliminating lean?

I'm trying to understand why/how loosening only one of the shutter valve screws like terdrocket did, works...

Practically speaking I want to know for my suspension install, because I was able to get one of my shutter valve screws to move, and the other is still stuck (after over a week of Kroil dousing, scraping with picks, and snapping one hex bit so far).

I couldn't find the exact answer on a search, so apologies if this has been rehashed before.

I did find the following (and read a lot more), and learned a lot in the process:

Interesting video (150 series but same idea, I think):

And the first two minutes of this (previously posted by Markuson):

And a good written description here: 2013 200 mods and effect on KDSS and other features

My rudimentary understanding is there are two circuits in the system. For simplicity, imagine one connects the top of each of the cylinders, and one connects the bottoms.

Also, there are two accumulators that keep near-constant pressure in the system despite the internal volume changing as the pistons in both cylinders extend and retract. If the system were completely static both pistons being forced in would drastically increase pressure and fail.

I -think- the accumulators are what allow the situation you describe where only one valve is opened and the system seems to balance. It allows pressure change on one circuit. I haven’t yet figured out why two valves would be needed for two circuits.. it points to three circuits and I think those accumulators are partly the reason for that.

 

[bloc]

Side note: looking at the FSM procedure the tech is supposed to go to at least 1015psi during bleeding but not over 1060 to avoid damage to the system. That is a pretty tight window.

Operating pressure is around 4-500psi depending on ambient temperature.

No good info yet on why two balance valves are needed.. I'll keep digging.

 

[bloc]

KDSS pump

 

[bjowett]

Looks like an OTC 4020, or a variant of it.

Air/Hydraulic Pump | OTC Tools

www.otctools.com

 

[gaijin]

Side note: looking at the FSM procedure the tech is supposed to go to at least 1015psi during bleeding but not over 1060 to avoid damage to the system. That is a pretty tight window.

Operating pressure is around 4-500psi depending on ambient temperature.

No good info yet on why two balance valves are needed.. I'll keep digging.

I'm sure you have already seen this diagram, but just because no thread can have too many pics, I offer it again here for completeness on the subject of KDSS (Notes in RED are mine and were used in the context of a different thread):

So... maybe if what is meant by "Upper Chamber" and "Lower Chamber" the reason for two valves might be better understood.

HTH

 

[bloc]

I'm sure you have already seen this diagram, but just because no thread can have too many pics, I offer it again here for completeness on the subject of KDSS (Notes in RED are mine and were used in the context of a different thread):

So... maybe if what is meant by "Upper Chamber" and "Lower Chamber" the reason for two valves might be better understood.

HTH

Thanks for this! In the bleeding procedure the FSM refers to the “upper” and “lower” chambers on the KDSS cylinders meaning above and below the piston.