Malibu V6-191 3.1L VIN M SFI (1997)
Suspension Strut / Shock Absorber: Testing and Inspection
Off-Vehicle Checks
All strut dampeners and shock absorbers should be stroked before attempting a bench check. When stored horizontally, such as new units in stock, an
air pocket will develop in the pressure chamber. An air pocket will also form if the vehicle has been stationary for a period of time.
Do the following to remove air from the pressure chamber:
^
Extend in vertical position - top end up.
^
Collapse in vertical position - top end down.
^
Do this again five more times to make sure air is purged from the pressure chamber.
Proceed with the actual bench check as follows:
1. Clamp a vise on the bottom mount with the strut dampener or shock absorber upright in the vise top end up. Do not clamp on the reservoir tube or
the mounting threads.
2. Pump strut dampener or shock absorber by hand at various rates of speed and note the resistance.
3. Rebound resistance normally is stronger than compression resistance by about 2 to 1. However, the resistance should be smooth and constant for
each stroking rate.
4. Compare with a strut dampener or shock absorber known to be good.
5. It is normal to hear a hissing noise. The following symptoms are abnormal and are reason for replacement.
A. A skip or lag at reversal near mid-stroke.
B. A seize (except at either extreme end of travel).
C. A Noise (such as a grunt or squeal) after completing one full stroke in both directions.
D. A clicking noise at fast reversal.
E. Fluid leakage.