Does manually hand-testing shock absorbers have any validity for checking if a shock is good or bad? Does hand-priming shock absorbers help?
I usually hand-prime shock absorbers that I feel are acting inconsistently or behaving not as it should. Usually they are shocks that have been sitting on the shelf for a long time, usually sideways, so it causes issues with the fluids in the shock.
Shock manufacturer I contacted states that it does not have any validity as to the status of the shock, nor does it help the shock in any way (i.e. for "priming" before installation) due to the forces it sees (or doesnt see) when hand-priming.
Basically was told that the only way to see if a shock is good or bad is to check for any leaks or to install the shocks on the vehicle and check for noise during operation.
I see installers have videos showing how to manually cycle or prime the shock absorbers before installation. I assume this means that they can see a benefit of some kind.
Also lots of people on forums and whatnot have posted about priming the shocks and reasons as to why and how it helps the shock absorber.
I have personally tried hand-priming shocks absorbers and:
- Noticed significant changes to behavior in my hand-tests among most of the shocks I hand-primed. Most of the time, they become much more firm and consistent.
- Minimal or no changes in ones I suspect were faulty. They had "dead zones" and behaved inconsistently before installation and even after riding on them for a while.
Example: I take off a pair of shocks that are the same product/model from a vehicle that has been riding on them for a while and hand-test them. The 1st is extremely firm and very consistent/smooth while the 2nd doesn't provide nearly as much resistance, is very inconsistent, is not smooth (has dead-zones).
Ignoring how it performed on the vehicle for this example, does the hand-test have any validity here?
I understand that hand-testing is not nearly as effective as a test on the vehicle or a shock dyno. But that is not what I am asking. I am only asking about the validity of hand-tests on its own merits, and not about hand-tests in relation to other tests or anything else.
Feel free to edit my question to make it better or make suggestions.