While Mercedes Benz ML350 hatch strut failures aren't terribly catastrophic in consequence, it becomes very inconvenient to have them damaged and malfunctioning. Can you imagine having to prop up the SUV's rear hatch every time you have to load something? Didn't think so. Here are a few ways to tell if things are going south, and the little things you can do to quick-fix it.
The first signs that your hatch struts are starting to wear out are a noticeable squeaking when you move your hatch up and down as well as a noticeable limp when the hatch is fully opened. That is to say, the hatch doesn't stay up all the way and instead precariously hangs over your head threatening to hammer it painfully. Ideally, by this point, you replace the old, worn hatch strut with a brand new working one. If you can't or simply don't want to, an option for a quick fix is to cover up the damage-which is most common-if there is any with duct tape. Done early enough, it can "re-pressure" the strut a bit giving a little bit of traction. Alternatively, you could attach a clip to the thin part of the strut to keep it propped up and prevent it from falling on your noggin'.
Another symptom that the hatch struts are wearing out or damaged is the occasional difficulty in opening the hatch at all. At times this can be manifested in greater resistance to tugging at the hatch. At worst, it actually "sucks" the hatch back to a close despite your best efforts and application of strength. This is a tougher nut to crack because it implies a greater fault with the pressures within the hatch strut itself-this should be a signal for replacement if there ever was one. The only real option if you have to access your hatch then and there would be to force it open from the inside. Again, however, if it gets this bad, start ponying up for a replacement to save you the heartache.