So I have been reading AHC threads for days but still would like some advice. I bought an 06 lx470 last month. When I inspected the fluid in reservoir was low and would not go into low or high mode. I topped off the reservoir and ran the test and from low to high it moves about 5.5-6 lines I know this is on the low side. I went ahead and flushed the system and put brand new fluid in. The lx drives better then it did and now goes from low to high without issue. On small cracks or bumps it drives fairly normal, however on big dips or bumps it drives as if it doesn't have suspension. I was thinking the globes are bad but I wanted to make sure before I invest the money to fix. Originally I planned on installing ome but its the wife's car and she is second guessing the mild lift. Thanks In advance for the help. Kevin
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Probably globes. Was the old fluid bubbly when you flushed the system? Can you tell a difference between comfort and sport?
After changing out fluid and giving it a comprehensive bleed the next step is to get your front and rear neutral pressures to their sweet spot. If you're seeing 5-6 grads then you're most likely looking at new globes, but even new globes won't perform as designed with high pressures which you probably have as you haven't shared this important info. Do the 16 step test [search] to see if you can isolate a single failed globe.
Last edited:
- Thread starter
- #5
I will try the 16 step test thanks for the help. The lx has 103,000 miles. I cant really tell a difference between comfort and sport and the fluid didn't seem bubbly at all it had the same constancy as the new stuff or maybe a little thicker just a total different color.
- Thread starter
- #6
Okay so when I do the 16 point test the fronts are hard as a rock. Doesn't seem to change from one setting to another. The rear starts out nice and soft and gets harder with each setting. Could I get away with just two new globes? Thanks Kevin
Yes you can just change out the two front damper accumulators - but unless you're itching to spend money I'd get the pressures dialed in first. I take it you don't have your own version of Techstream or haven't taken it to a shop for a pressure reading so you can tune the system correctly in a methodical way. So, on the strong hunch your pressures are high why don't you put on say 5 full cw turns on both TB adjusting bolts and see if that improves the front damping with your existing accumulators. Can't hurt and you may get a bit more service out of them if they aren't completely shot. Maybe a few more/less turns if the damping is improving incrementally. Even with new damper globes you're really going to have to get pressure readings and adjust the TBs (and probably coils/spacers) for optimum performance.
Last edited:
Can soneone post some pics of the torsion bars locations on lx 470 or rough guide.
Paddo by adjusting the torsion bars as I dont have techstream does that get the pressures right and help improve ride, and how would you know how many turns to adjust etc and which way. There's is 2 torsion bars in the front either side any in the rear.Thanks.
Tightening the torsion bars (turning the bolts clockwise) lowers the front pressure 0.2MPa per turn on both bolts; loosening raises the pressure. We know the target front pressure is 6.9MPa for optimum design performance and by knowing how far off that mark we are by reading the pressures in Techstream (or any other suitable device) we simply close the pressure gap by tightening (nearly always the case) or loosening the TBs. As these vehicles age the effective torsional rate begins to decrease and this causes the hydraulic system to work harder by increasing its internal pressure above 6.9MPa to hold the vehicle at N height. This negatively affects damping. We compensate by tightening the torsion bars which adds some "twist" which increases the TBs effective lift, the hydraulics therefore don't work as hard and the system's pressure is lowered back down to 6.9MPa at N height and all things equal damping should be at its best. You can fiddle with pressures to alter the torsion bar to "gas spring" damper accumulator ratios to try and get things even better as the damper accumulators age and loose pressure. There is no way off guessing how many turns you need to get pressures optimal: experience is that unless the vehicle's AHC has be tuned and maintained then it will have high pressures; by how much is the question, but many unadjusted AHC systems are initially 0.5-1.5MPa too high. No TBs in the rear, just coils and they can't be adjusted. Best you can do is add coil spacers to artificially increase their length or replace them (or both).
- Thread starter
- #11
I took it to a friend with an scanner seeing if any of this info will help. I took a few snapshots and then the info screen of maybe I looked at the wrong page. I really appreciate all the help. Going to raise the torrsion bars here in a few minutes. Kevin
Trying getting the reading after cycling from n to low to n.
Kevin you're on the right track but there's nothing usable there from the Snap On. You've got to have that screen up, lower to L then raise to N and read off the pressure fields when they've populated. You'll only read 0s if you just hook up and don't do the L to N raise. Did you clear the C1762? If not you can clear it without the scanner: IG off and short [using a paper clip, wire loop or similar] Tc and E1 in the DLC1 connector under the hood, IG on [you'll have Christmas tree dash lights flashing] pump brake pedal 9 times in less then 3 seconds, IG off and remove the short. Done.
Nice!
Thankyou PADDO.Do wheels have to come off or can we set the rig on h or n to ajust the TB.Might try with 3 turns each side see how it goes.I recently got a wheel alignment before I changed my AHC fluid I seen the tech underneath ajusting something.Car drives well.
Your front pressure is now good, rear at 7.3 is quite high if you're at stock weight and front/rear heights.
Last edited:
Leave the wheels on, the manual says to adjust on a flat surface so there's no point in lifting the vehicle either. You can do the adjustments in H if you like as it takes a little tension off the bars and may make it a little easier. I've measured only about 65 ft lb torque on the bolts when tightening them.
- Thread starter
- #19
I am at stock wright and height so to get the pressure better in the rear I need to lift it up by about 1/2 inch with a coil spring spacer? Also now that my pressure is good should I redo the test to see how my globes are? The ride is 60% better so far, thanks so much for your help. If you private message me your paypal I would like to tip you for all the help. Thanks Again Kevin
Regarding the rear coils/spacers and vehicle height if you raise the N height by adjusting the sensor position [sensor lift] then the pressure increases because the hydraulics is doing more work to raise the vehicle and maintain the new N height. Same if you add weight, more hydraulic work and increased pressures. Conversely if you lower the rear's height then the pressure lowers too. Stock rear height should be close to 20.5 inch hub center to fender bottom. Often we encounter situations where someone can't get their rear pressure down and it turns out they're higher than stock height without doing anything to compensate like adding spacers or replacing tired, set coils. By adding a set of 30mm spacers you'll decrease the rear pressure by about 0.5MPa but the vehicle's height won't change because the height sensor drives the rear height to its null, N position. Now as the hydraulics are doing less work (because the 30mm spacers have helped by effectively simulating a longer coil) you'll read lower pressures. Honestly the work to install spacers is identical to installing new springs too so I'd recommend doing new AHC coils (about $200) and spacers ($50-60) at the same time if you're paying someone. If you like doing this sort of stuff yourself then maybe just go with spacers and enjoy the improved damping that you'll realize with lower rear pressure and fit new coils with the spacers at a later date if you're so inclined.
Sounds like you're going in the right direction and improved damping is always a good thing. Just out of interest you can re do the L to H check, noting it will also get better with the rear pressure lower.
Glad to help and thanks for the offer but I come pretty cheap
Maybe buy a silver star to show your support for this great site?
Sounds like you're going in the right direction and improved damping is always a good thing. Just out of interest you can re do the L to H check, noting it will also get better with the rear pressure lower.
Glad to help and thanks for the offer but I come pretty cheap
Maybe buy a silver star to show your support for this great site?
Last edited:
