It’s really frustrating when you lose the spring on your pruner. That makes using your pruner far more difficult to use. If that happens to you, I may have a solution. You can see in the photo that I have a variety of replacement springs. You would think that one of these would fit your pruner. Well, I have found that springs are sometimes proprietary—they can only be used for one particular pruner. I figure my odds are better than 50% to be able to help you.
The second photo shows a badly rusted spring. If you soak a rusted spring in vinegar, it will remove the rust and work much smoother, especially with the addition of WD-40. Note that the top spring in the first photo and the treated spring in the third photo certainly don’t appear new, but they will work just fine. This may be the experience that hooks you on cleaning the rust off your tools.
It’s easy with springs because any small container will work. I use a measuring cup. If you choose to tackle the whole pruner, try a plastic take out container. It’s recommended that you dilute the vinegar to 50% with water. A black substance will replace the rust. It is different iron oxide that appears to shield the iron from more rusting.
Stan, The Rust Removing Man