LX570 AHC Globe/Accumulator Replacement
- Thread starter NKP Garage
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Its already been rebleed twice. Last one was approx 2k miles ago. It's getting harsh day by day.. and no consistency in damping i think I just might go with new accumulators.
Is there a PN for the red spring rubbers?
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My AHC was on its worst behavior right before my battery finally died.
Also, i need pics of the braid wheels!! Im jelly jelly
Red spring rubbers? Have a link?
I had leaking rear shocks. Replaced both left and right. Battery seems ok I think, it's a 2 year old battery but cranks right up. I guess globes it is then.
Oh and here's a pic of the car.
Light truck or metric/passenger rated 285 70 r17? What pressure are you running the tires? A lot of damping occurs in the tire…and if you’re rolling on 45 psi or so in those things, you’re likely transmitting every pebble on the road right through the tire and into your suspension system.
As cool as ahc is with its damping, automatically increasing pressure to compensate for extra weight on the vehicle and adjustable height, I do not think it has that wide of a range of damping capability…so if you hit a bump that exceeds it’s ability, it just doesn’t damp.
I’m beginning to think the trick with the system is to find the perfect combination of sidewall height, tire pressure, coil spacers, and wheel/tire weight to dial in precisely how much damping you want the vehicle to have.
There is an “envelope” that the system performs well in…but depending on what you expect, you may need to move things around a bit to get there.
Considering Lexus seems to have reduced the spring rate of the front coils around 2015, I expect they made an overall change in the design of the suspension towards comfort and away from “sport/handling.” The idea of low profile tires and relatively stiff springs (good for handling) on a 6,000 lb suv sounds goofy…but I suspect they were trying to slightly market the lx570 as a “luxury/sport” suv while the lc200 was marketed as a “luxury/Offroad” suv. The change in the suspension around 2015, I think, was a recognition that they needed to soften up the suspension a little bit since people really weren’t interested in a 6,000 lb sport handling vehicle. Comfort was, I think, the goal.
Upside to the pre 2015’s or so, is that I think they may be more readily laden with bumpers, sliders, etc because I think the coils are, relatively speaking, a bit stiff.
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To be clear: the rear pistons/shocks aren’t classic shocks and just because they have a grease slick and dust on them, unlike normal shocks, doesn’t mean they’re leaking. I’ve seen multiple posts of people replacing them at the instruction of an uninformed mechanic.
If your ahc fluid was low, it was leaking…if ahc fluid is static and there’s a grease slick/dust, it is not leaking…
P285/70/17, not LT. According to the tire pressure calculator I should be running 28 PSI, but currently I'm at 31 PSI approximately 2.1 Bar (stock 285/60/18 should be at 33 PSI).
Noted on the shocks. It was leaking really bad like literally wet with oil. Fronts are sweating but it doesn't need to be changed.
Currently at 85K. This happened about 2K miles ago after a road trip. The roads here aren't that great, so suspension parts tend to fail early.
What AHC fluid did you use to refill the system? Probably not a concern but there has been issues with using the oem fluid from the quart size plastic bottles in the US. The metal oem fluid containers are the answer.
Last i spoke to my Lexus advisor, they were discontinued and an advisory was sent out.
Over here the AHC fluid comes in 2.5 liters metal containers.
Have you had the AHC ecu scanned for codes? There are failures that can occur that are not reported by any lights on the dashboard..Does your easy access feature work? In a previous example, an owners easy access wasn’t working because one of the AVS valve actuators had failed. He was able to determine this by scanning the ecu.
Also, I would try letting the system function as normal (not turning it off). If you do have air in the lines, I have a fully unverified theory, that the system is self bleeding as it works during normal driving.
No codes. Everything seems to be ok. I've been driving with the AHC on for the past two days. It's a harsh ride still. I'm planning on installing new globes soon and have it properly bled. Hopefully its a smooth ride once again. Will post updates once it's done.
AHC off only applies in park BTW or otherwise stationary.
Me too, whenever i can, i drop to low on a decline, just to send any bubbles to the back. Don’t think it does anything though lol.
Whenever i pull AHC hose after a bleed at the shock, there is such a strong vacuum it fights hard and then pops like a champagne bottle. Zero fluid loss.
Me too, whenever i can, i drop to low on a decline, just to send any bubbles to the back. Don’t think it does anything though lol.
Whenever i pull AHC hose after a bleed at the shock, there is such a strong vacuum it fights hard and then pops like a champagne bottle. Zero fluid loss.
Warning! More unsubstantiated conjecture below!
The actual test for that theory would be to be in H while in the incline. Give time for bubbles to settle higher in the system, then drop to L to push the aerated fluid back to the reservoir. I think the biggest problem with that theory, is ideally you’d want the air to move towards the height control valve. I suspect it gets hung up high in the shock bodies and the hard lines back to the actuator.
I think the most we can hope for is the air bubbles to get dispersed through all the fluid in front of the height control valve and then when you push fluid back to the reservoir you are pushing a portion of the air out and ideally it’s replaced with non-aerated fluid. Do this enough times and the system will eventually be air free.