It is not necessary to purge air from non-spiral groove shock absorbers. These shock absorbers contain a gas-filled cell within the shocks reservoir. These shocks differ from spiral groove shocks. Spiral groove shock absorbers contain an air-filled cell within the shocks reservoir.

1. Remove the shock absorber from the vehicle.

•	For RWD vehicles, refer to Shock Absorber Replacement (RWD) .

•	For 4WD vehicles, refer to Shock Absorber Replacement (4WD) .

Important: Do not clamp the vise jaws on the shock upper stem threads or the reservoir.

2. Place the shock absorber in a vise.

•	Clamp the vise jaws on the top mounting stud of the shock.

•	Hold the shock vertically in the vise with the bottom end up.

3. Pump the shock at various rates of speed. Observe the rebound force.

•	The rebound force normally is stronger than the compression force (approximately two to one).

•	The rebound force should be smooth and constant for each stroke rate.

4. Compare this shock with a good shock absorber.
5. If you observe any of the following conditions, replace the shock absorber:

•	A skip, or a lag, at reversal near mid-stroke

•	A seizing (except at the extreme ends of travel)

•	A noise, a grunt or a squeal, after completing one full stroke in both directions

•	A clicking noise at fast reversal