I've been thinking a lot lately about my LX470 and its hydraulic suspension components. I've heard a few people say that the parts typically last about 10 years or 100k miles. So now my truck is 11 years old and I have 98k miles on it. So I am dreading the day that the parts start to crater. Supposedly the reason the accumulators fail is because the rubber diaphragms fail due to the stress of the increased pressure of fluid being pushed in and out of the accumulator. So in theory if you keep the setting on the "comfort" level and stay away from "sport" then the fluid should flow more freely causing the accumulator to last longer right? Being in sport mode will not let as much fluid in and out of the shock making MORE pressure while in comfort it would flow better with less pressure. What does everyone else think? When have your suspension parts needed to be replaced and how much did you pay?

The AHC system is extremely reliable provided: Fluid gets changed every 5 years/60K miles and not contaminated with water, brake fluid etc.
The 4 strut accumulators do 'wear out' , just like tires and brake pads. The 'rubber' diaphragm material ,like all polymers, continues to harden with time. After 4-8 years, depending on temperature history and road conditions, the diaphragm will develop cracks and eventually the gas gets out.
Go ahead and enjoy whatever ride setting you want, it will not in any meaningful way influence the accumulator life. You ARE well out on the life experience curve. 4-6 years is much more typical, but I have a neighbor with a '98, 75K miles, looks new, and rides perfectly. However, I am willing to wager a single trip over real bumpy roads with a heavy load will finish off the accumulators.

Heavier loads and rougher roads do cause the diaphragm to flex more and an old stiff one will be much more likely to crack and let the gas escape into the oil and on out the reservoir vent.

Dealer prices to replace all 4 runs $3000+/-
However, you can buy a better product on my web site (activesuspensionsystems.com) for $1400, and any mechanic can easily follow the installation procedure--no special tools or training needed. Figure at most 2 hours (really less than an hour). So total cost is about $1600--with a 3 year parts warranty.

Yes I have a link to your website and will buy from you when they go!! You need to frequent this forum more often. You're one of the few that reply for the LX470 that know what they are talking about!!

I hope the accumulators will last for a while longer. I just spent about 3k on the 90k service along with getting all fluids changed. When we evacuated for hurricane Ike almost a year ago we drove on a pretty far trip with the truck loaded down. Still smooth as silk and adjusted to the load properly.

i have a 99 with 101,000 miles on it. no idea about its previous history of fluid replacement, so is there anyway i can check it myself? also my truck seems to be leaning to the left (the drivers side is about 1 inch lower than the passenger side) but the AHC still operates and it self-levels pretty well unless the truck is really weighed down. whats happening here? should i just get rid of the thing? or are there some preventative measures i can take? 3 grand is not an option for a 22 year old college student to pay for a new suspension.

AHC fluid can be flushed and replaced for 50 bucks at a Lexus dealership. The fluid tank is on the passenger side closest to the fire wall. You can see the fluid level there.