I have a 10 or so year old dewalt cordless that is my go to tool on ALOT of projects Its served me flawlessly for many years but it seems to be slowly losing torque or power, even with a full charge....Is there any brushes I can clean or surface or lubrication I can provide to keep this thing alive? It pretty much owes me nothing but I'd like to wrangle every last revolution I can out of it.....