100 series with bouncy ride

[SaadUK]

Dear Guys,

I have a 2003 Land Cruiser. Eventhough I have changed all the four accumulators including pistons plus both the motors, shocks, springs and torsion bars plus bleeded it number of times by following the method described in pdf file provided in this forum. The problem is, the ride is still bouncy and terrible when compared to my other same model LCs. Am I still missing something?

Thank you

 

[uHu]

What's the height (physical), Neutral Pressures and the height readings from the three sensors at N level? Also the degree reading from the steering wheel has a bit of influence, but mainly on roll.

Which two motors, and piston have you changed?

 

[SaadUK]

Dear uHu,

I took the readings while the engine was turned ON with steering at 0.00 degress and height at N. Kindly check the attached readings. Best wishes.

 

[uHu]

To get the pressure readings, you have to first put it in low, let it stabilize, and the up to N again. Looks like you haven't read the manual

Re the height readings: When they differ that much, the AHC will not work.
If, with this reading, the car is sitting on a level surface, and it is level left/right, you have to adjust the front sensors so that they show the same.
If the car is not straght left/right, you first have to adjust the torsion bars, and make sure the steering angle shows between -30 and +30 deg when checking left/right height.

The steering angle doesn't show in this pic, but if it shows around 0 when the steering wheel is straight, you're OK.

 

[SaadUK]

uHu,

Thank you for the info. As I havent worked on AHC adjustment before, Ill be asking few dumb questions. Sorry for that.
So now the question remains, what values range should I be in for both the sensors? And the adjustment has to be done through sensors or torsion bars? thank you once again

 

[uHu]

Read my previous post again.
First, you make sure the car is on flat, even, level ground, and that the height is according to specs.
Second, you make sure the steering is in straight postition, according to TachStream.
Third, you make sure that the car doesn't lean left or right by measuring physically. If it does, then adjust torsion bars.
Fourth, check height readings in TechStream, should be around 0 (zero) for all three sensors. (+- 4 mm)

 

[SaadUK]

Dear uHu,

Thanks for the help. My scanner will arrive on Friday. So ill come with the pressure values as well. I'll be grateful if you can provide to Toyota Specs on the values mentioned below:

FR Height Control Sensor ___mm
FL Height Control Sensor ___mm
RR Height Control Sensor ___mm

Front Pressure Sensor ___mpa-g
Rear Pressure Sensor ___mpa-g
Accumulator Pressure Sensor ____mpa-g

That would be great help

Thanks again

 

[PADDO]

The info you're after was recently posted in PDF form. Search "AHC neutral pressure FSM". HTH.


Sent from my iPhone using IH8MUD Forum

 

[uHu]

Dear uHu,

Thanks for the help. My scanner will arrive on Friday. So ill come with the pressure values as well. I'll be grateful if you can provide to Toyota Specs on the values mentioned below:

FR Height Control Sensor ___mm
FL Height Control Sensor ___mm
RR Height Control Sensor ___mm

Front Pressure Sensor ___mpa-g
Rear Pressure Sensor ___mpa-g
Accumulator Pressure Sensor ____mpa-g

That would be great help

Thanks again

As Paddo said.
But, The values are not absolutes, or they depend on several conditions. You really have to read up, in the service manuals, to understand.

The Height Readings e.g: The sensor values should always be at zero when at N height, that's the whole point of the system
For the front, the value is averaged between the two (for input to the ahc); and if the two are too different, it will do nothing!!
The values will never be exactly 0, but close, like <10mm.
These height values have nothing to do with the real height of the vehicle, only relative to how the sensors are adjusted.
And remember that the hydraulic system is open between left and right when the steering wheel is straight. (Straight according to the steering angle sensor)

The pressure figures depend on at least 5 conditions, like actual height (not sensor output), weight, sensor alignment, and whatever else it says in the manual. RTFM