Hey is there anyway to check if a strut is bad before putting a spring on it? I want to check before I go through putting them on my car,

ummmm, just try to compress it by hand... if you can its no good

I don't think so, my illuminas could be slowly compressed by hand even at setting 5 but they work fine @ all settings I've tried when on the car. The thing is that after you compress them they go back out all the way.

A dead strut I think would be easy to compress and would stay compressed and wouldn't move back. That's what my dead stockers were like when I took them out.

well I have 4 stock ones off the car and 4 on the car. Ones on the car seem fine but I wanna test my old ones also..well i pushed one in and it was not easy to get in. It had a lot of pressure along with no leaks. But it didn not come back out by itself. So is it bad?

I think it means that it is still usable but it is on its way already.

Struts have oil and gas in them the gas is there to prevent oil form bubbling when going over lot's of bumps. Gas under pressure is what makes the shock expand when it's new. If the shock still has resistance but does not come up by itself it means that it is still operational but there is not much gas left in there. If you are working it hard (going fast on a long bumpy road) it will loose it's damping abilities quicker than a shock that still has a lots of gas inside.

ok so how long will it last like this on average?

it's anyone’s guess. But the point is that it is already not performing up to the standards and it won't keep it damping abilities for long which potentially puts you in danger. But if the driving takes place on smooth surfaces most of the time u can drive it until it will start leaking. That is what most people do anyway. It will be wearing out your suspension components faster not to mention it can potentially endanger your life.

I say you can keep them as spare parts if you just need to get buy until god shocks will arrive in the mail.

when I did mine I threw them out cuz I didn't have any place to keep them. and at 83k miles they had resistance and were not expanding by themselves. One rear one leaked and it had not resistance what so ever.