KDSS recharge - making my own SST

[Okusputokus]

See pic above in my previous posts, it's the part with "QC 90" on it. Got it at an HVAC supply store. Might need an adapter, take your hose with you, they may be able to provide adapter fitting.

[MENTION=167849]Okusputokus[/MENTION]
Did you ever figure this fitting? I am going through the KDSS clunk now and building the SST out to swap the cylinder.
Thanks for your info!

 

[Mitsuboost30]

Gotcha, not sure why I was thinking that was a different fitting.
So the nipples on the system are standard r134a HVAC connectors?
Thank you!

See pic above in my previous posts, it's the part with "QC 90" on it. Got it at an HVAC supply store. Might need an adapter, take your hose with you, they may be able to provide adapter fitting.

 

[Okusputokus]

Yes, they are. Cheers

Gotcha, not sure why I was thinking that was a different fitting.
So the nipples on the system are standard r134a HVAC connectors?
Thank you!

 

[Mitsuboost30]

Yes, they are. Cheers

Finally got around to building the pump and bleeding the system. All worked well.
Im stuck on the instructions. Am I reading this right?
Bleed all parts to 1015psi.
Then back down the pressure based on this fluid temp chart (attached), 415-420psi?

 

[Okusputokus]

Yes, that's what I have done the two times I've bled the system.

Finally got around to building the pump and bleeding the system. All worked well.
Im stuck on the instructions. Am I reading this right?
Bleed all parts to 1015psi.
Then back down the pressure based on this fluid temp chart (attached), 415-420psi?

 

[Mitsuboost30]

Yes, that's what I have done the two times I've bled the system.

Got it. Did you use the pump to lower the pressure or bleed it out?
Instructions are pretty straightforward, I, unfortunately, suffer from overthinking everything LMAO

Thank you! :cheers:

 

[baldrik78]

I gotta say, I sure hope I never need this thread, but I'm sure glad its here.

 

[krazywake]

I ended up letting out the ratchet strap and just letting the piston do what it wanted, didn't end up hitting anything(skids). No lean.

I also put my front sway back on for the winter since I wasn't doing much on trails and really want to fix the piston. I have bought a used piston and will install it in the coming weeks. 99% sure the internal nut in the piston has slowly loosened over the last few years. If you want to learn a bunch about KDSS follow Dr_kdss on IG. He's got some great aftermarket parts and diligently trying to make more options so that KDSS is more compatible with lifting etc.

Did you ever end up swapping out the cylinder with a new or known working one and then recharging the system? I'd like to know if this route was successful before conjuring up my own sst pump to attempt the same. My kdss system never showed any signs of leaking but the knocking in the front cylinder is pretty much constant over bumps and I'm sure beyond repair if there's actually an internal nut loose or damage.

Does a teardown of what one of these kdss cylinders actually look like internally exist anywhere on the Internet? I haven't been able to find one.

 

[Okusputokus]

Hey man, I did swap in a used front, recharged, seemed good for a bit, clunk came back. Also, a couple years later, replaced the rear with a new one, recharged, still have a clunk. Now I'm running no front sway, still have a clunk which means it's something else which is baffling because my whole suspension is less than a year old in different phases. My plan in the spring is to recharge it once more with front sway back on and try to find the clunk elsewhere using cameras or something. It's the same clunk for the last two + years, not really getting worse, I'm pretty much used to it and my OCD isn't fretting over it lol. Doesn't mean your clunk isn't kdss related, I'm assuming mine is lift geometry related, who knows.

As for the teardown, they are not, you have to cut them open and then they're toast. The internal shaft/nut is stuffed in there at the factory, and then stamp welded at the bottom. See pics

this is one I bought used and the cylinder fell out since the internal nut came loose! Luckily I bought it for the hoses and not the cylinder!

Did you ever end up swapping out the cylinder with a new or known working one and then recharging the system? I'd like to know if this route was successful before committing up my own sst pump to attempt the same. My kdss system never showed any signs of leaking but the knocking in the front cylinder is pretty much constant over bumps and I'm sure beyond repair if there's actually an internal nut loose or damage.

Does a teardown of what one of these kdss cylinders actually look like internally exist anywhere on the Internet? I haven't been able to find one.

 

[krazywake]

Damn that really sucks! But it's very useful beta/data point for those of us with lifts and kdss so thanks for sharing your experience. The photos of the internals of the cylinder are also helpful- not because I thought I could repair it but just to understand what may/may not be happening.

 

[krazywake]

Hey man, I did swap in a used front, recharged, seemed good for a bit, clunk came back.

Do you know if you are running a heavier spring rate than other basic lifts? For example I think I have the icon 700 lb/in to help with the weight of the front bumper. I'm thinking there might be a correlation to running heavier duty springs and destroying these kdss cylinders. I did notice my clunk came about the same time I went from stock bumper with 650lb/in springs to heavy C4 bumper and the 700 springs. Might just be asking too much from the older style kdss system.

 

[T4R_Canuck]

Do you know if you are running a heavier spring rate than other basic lifts? For example I think I have the icon 700 lb/in to help with the weight of the front bumper. I'm thinking there might be a correlation to running heavier duty springs and destroying these kdss cylinders. I did notice my clunk came about the same time I went from stock bumper with 650lb/in springs to heavy C4 bumper and the 700 springs. Might just be asking too much from the older style kdss system.

I think I understand what you're saying here, but I can't envision suspension spring rate would affect the KDSS cylinder, but perhaps overall suspension travel does. As far as I know, the KDSS cylinder doesn't actually hold any of the weight of the vehicle, it just flexes as the suspension cycles. I believe the only factor affected by a suspension lift is the angle of the outer kdss attachment points and the amount of droop it encounters during suspension cycles. I would imagine (purely speculation) that during max suspension droop on the driver side, it's possible the KDSS cylinder hits it max extension before the suspension does, which over time could kill the cylinder. The best way to prevent this would be to flex out the front suspension, and install limit straps that prevent the KDSS cylinder from being the only thing limiting suspension travel.

Let me know your thoughts.

 

[tpotnoc]

90k. Probably leave it as is for a while. I'd imagine that rear sway helps on the freeway. I have good flex back there with the Blackgate customs KDSS extenders.

Thanks for sharing all this knowledge. Can you share the bleeding/pressurizing procedure that you followed?

 

[Okusputokus]

Thanks for sharing all this knowledge. Can you share the bleeding/pressurizing procedure that you followed?

Funny, we connected on KDSS FB page! Sent it to you there. Cheers

 

[arthurm]

Can you post your method here please? If it's the same as the service manual, don't bother; I already know that. If it's simpler, as some others are doing, it would help us all.

FYI, someone recommends bleeding just at the accumulator at 700psi or so until no more air comes out. No need to mess at the cylinder bleed points, thank goodness as those are probably rusted on mine.

 

[Okusputokus]

Same as manual, very tedious bleed procedure, and I was approximate with pressure stages since it's difficult to be precise with analog display. I think it's important to bleed at the cylinders as I've see a lot of air come out of those.

Can you post your method here please? If it's the same as the service manual, don't bother; I already know that. If it's simpler, as some others are doing, it would help us all.

FYI, someone recommends bleeding just at the accumulator at 700psi or so until no more air comes out. No need to mess at the cylinder bleed points, thank goodness as those are probably rusted on mine.

 

[WenSamya]

Can you post your method here please? If it's the same as the service manual, don't bother; I already know that. If it's simpler, as some others are doing, it would help us all.

FYI, someone recommends bleeding just at the accumulator at 700psi or so until no more air comes out. No need to mess at the cylinder bleed points, thank goodness as those are probably rusted on mine.

I’ve been down the DIY rabbit hole with KDSS before, so I feel your pain trying to piece together the right fittings. I had a similar situation when working on a high-pressure hydraulic project for my buddy’s skid-steer. I ended up using quick couplers from Northern Hydraulics—they were a lifesaver. I stumbled across them after a frustrating day of trying to find something local that could handle the PSI requirements. Their site had exactly what I needed, and the quality was solid—no leaks, even under heavy use.As for your setup, I like the idea of bleeding at the accumulator around 700psi. It’s so much cleaner and avoids the headache of potentially snapping off a rusted cylinder bleed screw (been there, done that).

 

[arthurm]

Update: Dealing with a family member with dementia on a daily basis, I simply did not have the time to invest in a DIY effort.

So, I purchased the parts (from Japan: accumulator $550, front cylinder $520; from US Toyota dealers: front lines and bolts $240, fluid $133). Paid a dealer, familiar with the system, to replace all and refill $800.

Initially, I had asked to replace just the accumulator. However, since the front cylinder was heavily corroded, it and the lines were added to the job.

All in all, I am satisfied with the work. If I had purchased the pump/fittings for say $150, I would have saved $650. Big deal!

 

[mofokid69]

Update: Dealing with a family member with dementia on a daily basis, I simply did not have the time to invest in a DIY effort.

So, I purchased the parts (from Japan: accumulator $550, front cylinder $520; from US Toyota dealers: front lines and bolts $240, fluid $133). Paid a dealer, familiar with the system, to replace all and refill $800.

Initially, I had asked to replace just the accumulator. However, since the front cylinder was heavily corroded, it and the lines were added to the job.

All in all, I am satisfied with the work. If I had purchased the pump/fittings for say $150, I would have saved $650. Big deal!

Hey, can you give me some for info, I'm in the same boat, with the cold weather and lack of time it's getting harder to deal with this C1851 code, I want to fix it or delete either way the truck will drive better than it does right now. PM or reply here. thanks