G 2500 3/4 Ton Van V8-305 5.0L VIN M SFI (1997)
Suspension Strut / Shock Absorber: Component Tests and General Diagnostics
Diagnostic Information & Procedures
Bench Test-Non-Spiral Groove
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Purging the air from the non-spiral groove shock absorbers is not necessary. These shock absorbers have a gas filled-cell in their reservoirs (as
opposed to the air filled-cell in the spiral groove shock absorber reservoirs).
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Remove the shock absorber from the vehicle. Refer to "Shock Absorber."
1. Place the shock absorber in a vise with the jaws clamped on the shock absorber top mounting stud.
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The shock absorber should be held vertically in the vise with the bottom end up.
Important: Do not clamp the vise jaws on the shock absorber upper stem threads or reservoir.
2. Pump the shock absorber at various rates of speed and observe the rebound force.
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the rebound force is normally stronger than the compression force (approximately two to one).
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The rebound force should be smooth and constant for each stroke rate.
3. Compare with a good shock absorber.
4. If one of the following is observed, replace the shock absorber.
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A skip or lag at reversal near mid-stroke.
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A seize (except at the extreme ends of travel).
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A noise (grunt or squeal) after completing one full stroke in both directions.
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A clicking noise at fast reversal.
Rear Suspension
1. Remove the shock absorber.
2. Place the shock absorber in a vise with the jaws clamped on the shock absorber's top mount.
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Hold the shock absorber vertically in the vise with its bottom end up.
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Do not clamp the vise jaws on the shock's reservoir tube.
3. Pump the shock absorber at various rates of speed and observe the rebound force.
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Rebound force is normally stronger than the compression force (approximately two to one).
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Rebound force should be smooth and constant for each stroke.
4. Compare with a good shock absorber.
5. If any of the following problems are observed, replace the shock absorber.
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A skip or lag at reversal near mid-stroke.
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A seize (except at the extreme ends of travel).
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A grunt or squeal noise after completing one full stroke in both directions.
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A clicking noise at fast reversal.