Shocks: dead or not?

[packmule1911]

I grabbed what look to be Procomp shocks for cheap from an XJ with a blown motor.

How do you determine if they’ll still good before going through the trouble of installing them? They do not expand quickly when you push the piston in. Should they?

Thanks.

[4.3LXJ]

They should not extend quickly after pushing them in. I am assuming they have not leaked out nitrogen

[packmule1911]

These are hydro’s made by someone, and work, but they hiss when you hit a little bump, especially so when cold.

[4.3LXJ]

I think you are hearing the usual fluid transfer passing the valves within the shock. That is how they work.

[downsy]

Unless they have no or little resistance they're proabably still good

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[packmule1911]

I think you are hearing the usual fluid transfer passing the valves within the shock. That is how they work.
Haven’t had a set that hissed like this. Free is good, and they do work, but the sound is irritating.

[OldFaurt]

Shock simple evaluation:
Oil content:
Put one end on the floor in the orientation they would be used in and collapse them,
Q: Do they try to open to full length when you don't exert pressure on them and make little noise other than buzzing (valves)?
A: Good!

Gas Charge:
Q: Do they make hissing or cracks and pops during self opening up?
A: Gas loss, still functional but will go soft under hard use, gas is weak and oil will foam up.

Q: Do you have to pull them to full length?
A: No gas left, oil will foam up easily and will cause handling issues

Gas charge ONLY controls foaming of the oil during hard use
Oil content remaining becomes very critical with steering dampers / stabilizers
as air gap is more pronounced in use as it creates a much easier compressible pocket of air
that compresses quickly before it creates resistance to faster motion and under hard use, The oil foams.
Of course check for dings on piston shaft, oil around seal...
Don't use worn out shocks, THEY SUCK and could KILL YOU!!