Probably not - more likely to be the heating element.
Consider the point in the machine's cycle when the trip happens - spinning will place the greater stress on the brushes - heating the water the greater stress on the element.
Typically (rarely) bad brushes will not short to earth - typically (often) a defective element will short to earth.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix washing machines.