AHC Problem (1 Viewer)

[Greenland Landcruiser]

My LC100 with AHC has a little problem. It is tilting a bit to the left side (driver’s side), so I took it to the mechanics. The attached their computer and tried to align the height in both sides.
They fixed the alignments when it was raised and when it was in 'normal' height. But when it was lowered the ‘value’ didn’t match. They talked to the national Toyota corp. (Toyota Denmark) and were told to change the front-left-side AHC censor. So we did.
But now it is tilting a bit to the left side again! The mechanics troubleshooting computer is shipped to Toyota for an upgrade. In the meantime I would like to know if anyone else has experienced the same problem and have a good idea how to fix the problem.

 

[uHu]

any news

A few weeks has passed...
but anyhow:
Sounds to me like either a sensor,
or the torsion spring tension (which is adjusted after measuring the pressure of the AHC fluid for the same wheel)

 

[Greenland Landcruiser]

According to my local Toyota dealer/mechanic it was a torsion/tension-thing. He fixed it. Thank you for your post and marry x-mas.

 

[hoser]

Greenland, anyway you could expand on "torsion/tenion" thing? Was it a simple adjustment?

 

[tom.]

Hi.
I have got a similar problem. In low, normal and high mode car is leaning about 1 inch to the left side (front and back). I have been to the Toyota dealer and they told me that all 3 sensors need to be changed (1100 pounds). They did not even try to adjust anything and told me about abnormal reading from sensors. After I read these coments I started to wonder if it is necessary.
I will appreciate any advice.

Regards.

 

[hoser]

I doubt all three sensor went bad at the same time. You can remove each sensor (mark it's location first) and test them individually. If you don't have the manual, I'll have to dig out the specs later. The problem with the sensors is they don't block out moisture well. Some have had success with cleaning and resealing them.

 

[tom.]

I do not want to touch this by myself. I even do not know where sensors are. What is a warranty term on ahc sensors? I heard somewhere that Toyota extended warranty for them but I am not sure for how long and if it is true.

 

[Texasoil]

AHC tilting

While a bad sensor MAY cause uneven heights--99.9% of the time they can be adjusted to level things out. USUALLY, if a sensor fails, the system will trigger the trouble light and shut down. If the leaning is to the driver side, and develops over time, tightening up the driver side torsion bar will usually correct the spring sag.

The goal is level ride at Normal height.

 

[tom.]

I decided that at first I will try to clean these sensors by myself. Could you please tell where they are and if is it difficult to take them out and fit it back. Maybe someone could put a pictures of suspensions with markings where they are.

thanks.

 

[hoser]

Tom, check this diagram for location. Basically, there are three terminals on each sensor. You connect 4.5v (3 dry cells) at two terminals and test the voltage reading across the range. It will be .45 volts on one extreme of the range and 4.05V on the other. Clean/seal faulty sensor. PM me your email address for better diagram of the terminals.

 

[uHu]

Here some pix of the innards of the rear sensor

How's'it going? Got the sensors off yet?

 

[tom.]

I will have got some time this saturday to check these sensors and torsion bar.
What can I use to seal them in?

 

[tom.]

Thanks for all suggestions and photos. I have checked sensors and they all are like new and work fine. I have sealed them up with Loctite silicon 595. Then I adjusted Anchor Arm Adjusting Bolts on left and right and car is now in level.
Additionaly I tighten left bolt so much that only like 3/4inch left, so I wonder if it could cause any damages to another suspension components?

Is there any adjustment point where I can soften suspension? The car have rough ride in every mode including comfort. There are some differences between sport and comfort, but comfort is not comfort . I have a feeling like this is changing depends on road conditions and speed but not always in the same way. This problem I had before I started with any adjustments.

 

[hoser]

Sounds more like the problem is the accumulator(s) It is the sphere shaped part located between the running boards and frame rails. Did you notice a drop in AHC fluid in your reservoir?

 

[LandCruisers4Life]

I know the best way to fix the AHC crap - take it out and put in a regular suspension!!

 

[tom.]

I did not notice any changes, I have the car for five weeks now. I did the test described on B&B Suspension Blog and everything seems to be ok apart the test with speed bump.
Tomorrow I will try with different tire pressure, I have got 32 PSI front and back.

Perhaps there was and is now (set by me) wrong vehicle high.
Now in normal mode: front is 52cm (from spindle center to lower fender edge), back is 54cm.

 

[hkeller]

Just FYI, mine tested fine in terms of the numbers of gruduations of fluid fluctuation when moving from low to high, but I still need accumulators.

 

[tom.]

I do not know if it is accumulators fault but I need to be sure, they cost 2000 pounds. Sometimes car is ok, especially on motorways (even on bad surface). But most of the time (in city) is rather rough. I do not know what to expect from this car. This is my first 4x4. Before I have had Toyota Avensis (not on US market) and the ride was much more pleasant in terms of comfort (not space and equipment). Maybe I need to try another Landcruiser if it is a normal ride for this kind of car?

 

[hkeller]

I agree with a comparison test ride.

If, after the ride, you still yours is riding rough, I suggest change the ahc fluid before you do the accumulators. If it fixes it, great. If not, you have taken a step toward purging any contaminated fluid.

 

[tom.]

I would like to set up the correct vehicle height in normal mode. I found so many different meserments on this forum so I do not know which one is right. I have got 2002 LC before modernization and I asume that the correct value is shown at the bottom of this table: front 83mm, back 71mm. Is this correct?