The UZZ32 suspension contains a total of 7 nitrogen-filled accumulators:
- the four accumulators located at the bottom of each suspension strut act as "Gas Springs" in lieu of conventional springs
- additional accumulators on the Suspension Pump and Valve Body serve to provide a store of energy and to even out undesired fluctuations
The nitrogen is under high pressure and tends to leak out over time, rendering the suspension harsh. Replacement accumulators are no longer available from Toyota, but the existing accumulators can be re-gassed if required after minor modification.
To re-fill the Nitrogen in the suspension accumulators;
- Remove the accumulator
- Install valve
- Fill with Nitrogen
Removing the accumulator
To remove the accumulator:
- Remove the wheel
- Clean the suspension components and surrounding area so that a) you can see what you're doing, and b) the dirt does not get into the threads of eg the nuts & bolts
- Apply suitable lubricant / (eg Penetrene) and let sit for a while to help release the bolts.
- Release the hose clamps around the rubber boots that protect(ed) the suspension piston.
- Unscrew the "cover" that joins the top of the accumulator to the rest of the suspension strut. This will likely need a pipe wrench (diameter of the cover is approx. 75 mmm)
- Unscrew the suspension piston. For the Front, this will require a 36mm spanner. Note that the spanner can be no more than 8mm thick
- Unscrew the speed sensor / wiring which is attached to the (upper) control arm.
- Unscrew the 19mm nut that holds the accumulator to the lower A-arm
- Unscrew the 19mm nut that hold the upper A-arm in place and remove the bolt. As this bolt is quite long, you will also need to remove the front side wheel well /engine under cover.
Optionally, re-build the suspension struts and/or check & replace the suspension bushes while "in the area".