I would check out Margie Lawsons EDITS method described in her Empowering Characters' Emotions. This package is not free but in my opinion, it's well worth the money.
Lawson has divided the literary text into several different components, dialog, description, etc and she discusses rules for distributing them in the text. For instance that a scene should start with some description.
However, the overall rule is to mix different types of components. The EDITS method is about color-coding the manuscript with highlighting pens. Then you place it in front of you and if you have page after page of the same color, you can tell you need variation.
A part from that, I know of no rules per se, it's more about feeling. Or, for that matter, listening.
Read your text, or have your computer read it (if you're not quick to cringe...) and you should be hearing if something drones on and needs to be cut out.
However, dialog is one of the greatest tools not only for showing character but also to up the tempo of the text, so if you don't feel the text is babbling on or getting stuck, I suggest aiming for more dialog rather than less.