Disclaimer: Any work you perform on your furniture is at your own risk. Tension springs and reclining mechanisms can seriously injure you. Seriously.
As mentioned on the Mechanism Care & Operation page, if you're well-acquainted with your chair, at some point you may begin to notice some changes. Things may begin to feel loose, or you may hear sounds that weren't present before. These are indicators that your reclining mechanism may need some attention.
Often it's a simple matter of tightening hardware that has loosened over time with normal use. For example, a loose or wobbly footrest may require tightening of the fasteners that secure it to the mechanism. While a mechanism that is no longer closing smoothly may have loose parts or have come loose from its mounting location on the frame.
When the metal brackets that attach the back frame to the seat come loose, the back will start to lean or feel like it's falling away on one side. If you catch this in time, the fix is simple. Just tighten the loose back bracket fasteners.
Tip: If you overtighten certain fasteners on some mechanisms, you can cause damage. To avoid this, keep in mind that snug is sufficient. Never strong arm when tightening.
If your recliner has a pillow-style back, like the one pictured here, you may be able to restuff it yourself. Feel for zippers along the bottom of each inside back section. Or if the pillows lift up (yes, some do), look for zippers on the backside. These are a cinch to restuff -- no repair tech required.
Just be careful not to get any padding caught in the zipper!
Also see, Common Problems