AHC question for 99 lx470 please

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hankandjed

10 Year
Joined
Sep 20, 2014
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7
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i have a used 99 lx470 that i bought with 107k miles, everything is stock, no lift. just had the 90k service as it was never done with PO and i changed all the AHC fluids with lexus-brand fluid. my AHC works fine from low-high, but i have a really bumpy ride in the rear and can feel every crack in the road when driving to work through the truck but just in the rear.

rather than change all to OME lift bc i'm still pumping money into my xj cherokee and rather than rebuild the entire AHC system which seems to be working well, can i just replace the rear coils with OEM coils and will this buffer the ride a bit? i know these LX coils tire easily but i don't want to rebuild the entire suspension at this point until i finish with my jeep.

do i need to ask my local toyota tech to adjust torsion bars also?

thanks for your assistance with this matter, scott in NC
 
hankandjed said:
i have a used 99 lx470 that i bought with 107k miles, everything is stock, no lift. just had the 90k service as it was never done with PO and i changed all the AHC fluids with lexus-brand fluid. my AHC works fine from low-high, but i have a really bumpy ride in the rear and can feel every crack in the road when driving to work through the truck but just in the rear.

rather than change all to OME lift bc i'm still pumping money into my xj cherokee and rather than rebuild the entire AHC system which seems to be working well, can i just replace the rear coils with OEM coils and will this buffer the ride a bit? i know these LX coils tire easily but i don't want to rebuild the entire suspension at this point until i finish with my jeep.

do i need to ask my local toyota tech to adjust torsion bars also?

thanks for your assistance with this matter, scott in NC
Click to expand...
I would guess you get more "damping" from the AHC globes, but the springs may help and are a lot less $$.

What's your damping switch setting??...to me that makes a very noticeable difference.

Steve
 
If it were me and money was tight Id give the rear globes and accumulator a quick bleed, check/replace my rear sway bar links, adjust my tire pressure etc. all the cheap fixes. Usually the bumpy ride is globes.

Did the previous person pull anything with it?
 
i have tried all the different settings from comfort to sport and do not notice that much difference in ride, still feel the bumps and i know i shouldn't be feeling them through the floorboard. i have it on the 2nd switch now from the left of comfort.

no, he just changed and flushed the AHC fluids. should i bleed the globes and accumulators and see if that works? if i do, do i need to order more of the AHC fluids? i read a writeup on that on this forum a month ago and cannot remember but i can find it. thx, scott
 
i would bleed the globes and accumulators. Its the cheapest of all the solutions. Maybe you have fluid contamination or small air pockets.
Sounds like you just need a little more dampening to get by for now. Yes,you will need more AHC fluid.
 
ok i did some research on the forum now and found a link just like my issue. bought it from texas in the heat and would bet it is all the globes and dampeners. may just do an OME lift rather than spend 4200 on this AHC rebuild.
 
Knowing your neutral pressures tells you a heck of a lot, don't throw money at it till you have readings for your front and rear. That said, if you have original coils they almost surely need changing out to get the rear pressures down and it's a solid bet your TBs could do with a turn or two to get things in spec. By all means check the tires, link ends etc. There are a few of us here in the Tar Heel State who could help you out. Pm if you like.
 
yes I have
my 99 is a florida truck and it took almost two full containers of AHC fluid to flush the system. I can't comment of ride quality because when it rolled off the trailer it was the first or second thing I did so I didn't have a chance to do a before and after ride quality test. In your case id pickup a can of AHC and bleed the rear globes and accumulator and see what happens. They may be flat but again it sounds like your just trying to get some dampening until you move to your OME setup.
 
i pm'd you and would ask, can i test my pressures myself or should i take it to a dealer? i'm very handy underneath jeeps for 7-years and rebuilding but don't know much about the AHC diagnostics.
 
sounds good, i may just try this for now. can do OME lift no problem but just want it to ride better for the present time until i finish my other projects with rear disc brake conversion and lift on jeep. thx richie. i'll try it and let u know if any impovement. did u get your fluids directly from lexus dealer or online?
 
Your LX probably rides about like mine does. The AHC fluid wasn't really changed out until I bought it. Small bumps are the worst. Have about 7 gradation marks on the reservoir from low to high. My pressures are in spec and have new rear coils. I'm probably going to keep it and put a lift on it in the next year or so. If the wife really wants a LX with AHC, I'll get her a '03+.
 
Toyota/Lexus part number # 08886-01805. I bought it from a lexus dealership. Someone will probably correct me but if I remember correctly you should put the truck in Low make a mark on your AHC reservoir and then kick it into high and see how many hash marks of fluid had dropped. Its supposed to be an indicator of globe health. If the difference in markings of fluid is 7 or more hash marks than your globes are in acceptable health. The higher the number the healthier the globes. My 99 was just a tad over 7 marks so my globes are on the well worn side of acceptable.
 
If you have the mini-VCI with Techstream then you can read th epressure and do lots of other stuff.
 
This sounds like busted globes. It's easy to count the graduations on the reservoir as mentioned above here. If the globes and coils have not been changed ever, it is more than likely that they all need replacement.

There are lotsa threads on this forum covering all your questions, if you don't mind digging and reading a bit.
The AHC is a pretty simple system if you just get an understanding of it (which, btw, is what most dealers lack).
And yes, TechStream or t0yota Tester is a requirement for AHC diagnosis and maintenance.
 
hankandjed said:
no, he just changed and flushed the AHC fluids. should i bleed the globes and accumulators and see if that works? if i do, do i need to order more of the AHC fluids? i read a writeup on that on this forum a month ago and cannot remember but i can find it. thx, scott
Click to expand...
The globes are self-bleeding once the fluid is changed and the 4 globes and accumulator are bled as part of the change...more or less similar to bleeding brakes.

Steve
 
you are all awesome and i appreciate the time you take to provide feedback. especially to stephen in charlotte (99richie) for taking 45-min of his free time this friday to call me out of the blue when i was underneath my jeep and he was in his garage working on cars, walking me through the steps and physics behind the entire AHC system. i appreciate it sincerely, scott
 
no ride is still bumpy. tightened torsion bars 1-full turn and very slight difference and dont want to turn them anymore until i get pressure readings, but i just received my techstream and found an old dell notebook in my basement that will hopefully accept the software as all my other comp's are macs. will run a diagnostic test today and let you know, may need some assistance with the readings. thx, scott
 
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