I always assumed if a shock is not leaking and has compression/rebound functions working it is still good. Along with this, if tires are wearing normally, the shocks would be functioning normally.
On my Accord, I 'bounce' on any corner of the body, the car will rise and stop, without pogoing. To me the shock is good; same with the ST.
Where am I going wrong here?
Hey, Fred:
Fun topic, huh?
For clarification purposes: the tires are an important part of the suspension system, as are any other compressive, tensive, or elastic parts, and their positions relative to their paths of travel. "Reading" the tires' wear is a really good indicator of what is going on elsewhere. It may take more time to wear-in the tires than to check for other parts which are worn out, though. But back to your question.
I'm not sure that you are doing anything wrong. Bouncing the car is a fine way to estimate one segment of the shock's rebound damping ability. It does not check much of the compression stroke, though. It is the compression stroke damping that most of us look for in shock performance. There's much more to it than that, of course.
If one pushes down on the corner, as you described, the shock's spring pushes back with an equal effort (balanced forces). When you release the car's corner, the spring's upward force against the car body's downward force becomes unbalanced and pushes back against the car's mass. This continues until the spring's force and car's resistance to movement, as effected by gravity, balance. At that point both the shock's spring/rod and the car body stop moving. Unless one can provide the force required to pass the spring and damper through their entire compression stroke and rebound stroke, I doubt that there is much one could learn from this exercise. Kind of like kicking the tires; it no longer tells us as much as it used to.
Looking for oil weeps around a failed shock's body, and not finding any, is not that uncommon. I don't know where the oil goes. Sometimes it just isn't "there".
Riding along the roadway, intentionally riding over rough areas, can easily compress or extend the shock's spring and damper, sometimes to the point where all of the shock's travel is used. I'm just not sure that this is a safe way to check for suspension wear, but it is a way. Using a shock dynamometer is a safer way, but few of us have access to one. I like to ride along a familiar course, noting how irregularities "feel". I know what I like -- as does everyone else. My job is to make changes to my bike's suspension until I get "that" feel. Like the old saw about what is "art": I know it when I see it.
To paraphrase a wiser person than I, it ain't that hard; it ain't that easy. It surely is fun though!
Have a terrific Holiday season,
Marshal