Fixing a KDSS lean
the KDSS system
The following should not be taken as instructions. It is simply a documenting of the procedure I followed to rectify my own lean. No warranty is provided as to the accuracy of the information, and/or whether it applies in your situation or to your vehicle.
- There are potentially lethal dangers resulting from the vehicle moving during the procedure.
- There is the potential for expensive vehicle damage from improper procedures.
If you undertake your own KDSS fix, you do so entirely at your own risk.
Solving a KDSS Lean
Step 1: Preparation
- Measure the distance from the bottom of the wheel to the bottom of the guard on each side of the vehicle. Note the measurements.
- Locate the KDSS valve box, attached to the LEFT chassis rail (between the muffler and the chassis).
- Loosen the two shutter valves a maximum of 3 turns, using a 5mm allen key. See photo.
If you undo the valves more than three turns, it could allow air into the KDSS hydraulic system, which would require an (expensive) bleeding procedure to be completed by a Toyota dealer.
Step 2: Drive up on the wood
- Park the vehicle on a hard, level surface.
- Put your 75mm-high piece of wood in front of (or behind) the LEFT REAR tyre.
- Drive the LEFT REAR tyre up onto the wood.
- As an alternative, you can also place a jack under the LEFT REAR AXLE HOUSING, and raise until the tyre is approximately 50mm off the ground. (The 25mm difference with this method is to allow for the flex in the tyre).
Step 4: Drive back off the wood and check results
- Drive the vehicle back down off the piece of wood
- Measure the wheel-guard distance on each side:
- If the side-side measurements are within 10mm: You're done.
- If it's still leaning (but by a reduced amount): You can repeat the procedure, but increase the height of the object you drive onto (eg: to 100 or 125mm), or jack the axle up higher.
- If there is no improvement: You may have to fit a strut spacer or longer springs to the right side of the vehicle, or you could have a leak or fault in the KDSS system. Either way, you will need to have the vehicle assessed by a suspension specialist familiar with the KDSS system.
- While it may seem counter-intuitive to increase the lean in order to rectify it, this method works due to the way the KDSS system balances. The other alternative ie: Jacking up the right side of the vehicle to make it more level, then operating the valves, does not work.
- KDSS is an entirely manual hydraulic system. There is absolutely no connection or control between any part of the KDSS system and any sensor or electronic system on the vehicle. Therefore, there is nothing to be gained by 'resetting' the ECU or making any changes to it, in order to correct a KDSS lean.