1990 300CE trunch lock intermittently works. When it doesnot work I have to push down hard, sometimes bank on the lid, and then push to button to open. I have made adjustments up and down to no avail. Does this mean the lock needs replacing.
Thanks

Try using a lube. I would suggest a teflon of some sort. Be sure and use it sparingly though! I had the same problem with my C-class trunk, and that cleared the problem. Good luck, and DON'T use WD-40!!

Nylon and rubber lubricant worked wonders for my boot lock!It also mended the electric aerial and made the electric windows twice as fast and run more smoothly-fantastic stuff!!!