Did some brake detailing last weekend and I have a question. Was careless not to notice.

Left side / right side ? Now is the drivers side considered the left or right.
From the drivers point of view it's the left, from a mechanics point of view (under the hood) it's the right.
This question pertains to the mounting brackets for the front calipers, one is marked "L" (left), the other "R" (right). Rear mounting brackets don't matter, both are the exact same and are not marked.
Thanx !

 

It's from the drivers point-of-view... drivers side left, passenger side right.

 

Also, if those marks were not legible, each caliper goes to the side that if installed would leave the bleeder valve above the brake line.

When you install them backwards, the bleeder valve is under the brake line and the brakes won't bleed properly. Don't ask me how I know this.......