KDSS issue while replacing shocks and springs - help needed

[Adam from PL]

Hello All!

I have decided to replace the springs and shocks on mu 2016 LC200. The problem at hand is that the 2 valves on the KDSS regulator located mid frame on the left side (marked on the picture) are rusty and can't be unscrewed. The fact that they are a tiny 5mm allan key operated does not help

The car is back on the wheels and we need to either open these valves or bleed the whole system (via air bleed valves at each wheel) to put the suspension elements back together.

The question:
if we don't touch the rusty valves and just bleed the KDSS can we then pressure fill it again without opening these two valves?

Time is of essence as I am supposed to leave for Africa for 5 weeks on Thursday, so removing the regulator to work on these rusty valves on a bench is really not considered....

Any of you familiar with KDSS be so kind to advise.

 

[linuxgod]

You don’t have to loosen them to swap the suspension, it’s just a lot harder to muscle everything into position.

If you do try to loose them have someone weld a hex nut to them and turn that, after dousing for a few days in kroil

The system is 600psi. You don’t bleed it. If you have to replace the valve it requires a special Toyota tool that is hard to come by to repressurize it.

My vote is don’t bother opening them, the system will eventually equalize itself after a few days, just be prepared to use prying bars and ratchet straps to fight everything into position

 

[Adam from PL]

seems impossible now. a big guy has not enough strength to put the stabilizer rod or steering rod in place!

 

[linuxgod]

seems impossible now. a big guy has not enough strength to put the stabilizer rod or steering rod in place!

KDSS is linked. Push up on one rear wheel and a front wheel drops down. Or push up on one front wheel and the other drops. You can use that to help reposition things.

For the front sway bars, use ratchet straps to help guide it into position. A jack under one wheel can help. Sometimes you need to jack up the opposite side instead.

My dealer doesn’t open KDSS valves when doing suspension work. “Too many issues”. They do everything with the system intact. So it’s definitely possible to reassemble whatever you have apart, but there are tricks to it.

 

[Adam from PL]

@linuxgod - thank you for your input We did just what you said and it worked. Now only a visit for geometry and the car should be ready.

 

[patride71]

A bit of a hijack here....so I had the bright idea of dropping my front swaybar while replacing my tensioner and belt. I was struggling getting my breaker bar high enough to retract the tensioner to put the belt on. I was not thinking about the KDSS when I did this, so naturally I can't get my swaybar back into position to bolt it back on. I seem to not understand KDSS in the sense of reducing the hydraulic pressure. Is it as simple as turning the screws the 3 turns or do the wheels have to be off the ground? I did some research and had seen folks putting the vehicle on a lift, turning the screws, and then putting the vehicle back on the ground. Can I just reduce the pressure while all 4 wheels are on the ground? I don't have a lift and really don't want to put the entire vehicle on 4 jack stands if I don't have to...thanks for any feedback.

 

[bloc]

A bit of a hijack here....so I had the bright idea of dropping my front swaybar while replacing my tensioner and belt. I was struggling getting my breaker bar high enough to retract the tensioner to put the belt on. I was not thinking about the KDSS when I did this, so naturally I can't get my swaybar back into position to bolt it back on. I seem to not understand KDSS in the sense of reducing the hydraulic pressure. Is it as simple as turning the screws the 3 turns or do the wheels have to be off the ground? I did some research and had seen folks putting the vehicle on a lift, turning the screws, and then putting the vehicle back on the ground. Can I just reduce the pressure while all 4 wheels are on the ground? I don't have a lift and really don't want to put the entire vehicle on 4 jack stands if I don't have to...thanks for any feedback.

The screws don’t reduce pressure. They open extra circuits that connect the tops and bottoms of the rams so they can be moved independently. Otherwise they are locked together.

There will still be some force pushing down on the front and rear rams, but that force will be manageable with a floor jack or ratchet straps. The same operation with the screws closed requires a whole lot more force.

For the record, never unscrew them more than 3 turns!! Doing so can cause the system to lose pressure suddenly and getting it back in operation requires a rare and expensive tool as well as some specialty procedures.

More reading and some diagrams on the KDSS system operation here:

Thread 'Anatomy of a KDSS valve'

Oct 27, 2020

I think you guys and gals are gonna like this..

HUGE thanks to @jimoldguy who shipped me his rust-damaged KDSS valve after it was replaced for him with a new one. That can't have been cheap. Fortunately for me he kept the old one, and when I PM'd asking if he'd send it for a project I'm working on he boxed it up.

So my plan was first to clean it up to the extent I could, to avoid tetanus, then cut the thing up and understand it. Then, post all of it. The eventual goal is a comprehensive thread on our KDSS system with details on the functions of it, and this thread is one small part...

• bloc
• Replies: 53
• Forum: 200-Series Cruisers

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[patride71]

Thanks Bloc! This is very helpful.

 

[albIV1980]

2013 LC KDSS valves stuck on the " valve box" . and I need to address lean I created when replacing bad sway bar link. Previous owner /someone tried to weld on a bolt but it is all boogered up and not gonna crack open. Trollholes Cruisers suggested go ahead and replace 48006-60024 "Stabilizer Housing Sub Assembly with fluid' ie the valve box. but suggested let dealership do it so can repressurize. Took it in and they gave me estimate for $12,500 for all they say they have to do including take down exhaust/cat/muffler( that alone was $5000) among many other things I just dont need messed with. My question, can one of the kdss lines off of the box be loosened to get the pressure off the system or is there an alternatve valve somewhere to release pressure. I am fully aware of the pressure otherwise would have already drilled out one or both of the valve screws. I would love to be able to take everything down myself and then just get it to dealership to fill/pressurize.

 

[patride71]

A bit of a hijack here....so I had the bright idea of dropping my front swaybar while replacing my tensioner and belt. I was struggling getting my breaker bar high enough to retract the tensioner to put the belt on. I was not thinking about the KDSS when I did this, so naturally I can't get my swaybar back into position to bolt it back on. I seem to not understand KDSS in the sense of reducing the hydraulic pressure. Is it as simple as turning the screws the 3 turns or do the wheels have to be off the ground? I did some research and had seen folks putting the vehicle on a lift, turning the screws, and then putting the vehicle back on the ground. Can I just reduce the pressure while all 4 wheels are on the ground? I don't have a lift and really don't want to put the entire vehicle on 4 jack stands if I don't have to...thanks for any feedback.

It ended up being a piece of cake. I had to use a breaker bar on the KDSS screws, but once I broke them open they turned easy and just went with the 2 full turns. From there just used floor jack and block of wood to put the sway bar in place for reattaching.