Hi, I bought an older bike and it has "LUX" brand pads on it. the brakes are a side pull system. but one pad is on one way and the other is on upside down. how do I tell which way is correct for both? looking at it from the threaded side the top is curved and the bottom is flat.
thx
Marty

A photo or two, please.

Look at the pad holders. They might allow for pad removal and replacement. If that is the case, the closed end points forward, in the direction the wheel is rotating. If the closed end were placed at the back, the pad would be pulled out when the brake is applied.

That said, pictures would help us better understand the situation.