I took off my o-rings on my TK40 to clean and relube them and the threads. When I put them back on they end up twisted. What's the proper way to install them to prevent twisting?
There is a small tool called an o-ring pick that has a hook on one end. Use the hook to move the o-ring into/out of the groove. Places that sell o-rings will also sell the tool.
Usually if you just rub them around with your fingers they should right themselves. Before you replace them make sure they are straight, then try to push them down to their seat rather than rolling. Should do the trick.