Most measurement errors and inaccurate results come from how the photo was taken.
Start with the three basics below. If the measurement still fails, work through the checks at the end of this article.
If the measured value or the measurement position is wrong, you can also correct it manually. See Adjusting brake pad measurements manually.
Three basics for capturing images
1. Where to shoot from — through the caliper inspection window
Take the photo through the inspection window of the brake caliper.
You can capture and measure from other positions, but even then, keep the camera as level as possible relative to the brake pad. If the camera is at an angle, the brake pad appears distorted in the image, which can affect measurement accuracy.
2. What distance to shoot from — 20 mm to 35 mm from the pad
Hold the camera against the inspection window and keep a distance of 20 mm to 35 mm from the brake pad.
3. What and how to shoot — the three parts, with the laser perpendicular
Emit the laser perpendicularly and fit all three parts in the frame: the brake pad (friction material), the backing plate, and the rotor.
If the measurement fails even when the three basics are correct
Check the following in order, then take the photo again.
A. Is the laser being emitted correctly?
Make sure the laser is not split into several points by reflections, and that it is not distorted or stretched by hitting an edge or a step between parts.
B. Are the brake pad and rotor extremely dirty?
Heavy dirt can hide the boundary between the parts. Clean the area if needed.
C. Is the image distorted?
Check for camera shake, glare, or a distorted video feed. Reconnect the camera if the feed is unstable.
D. Does your smartphone or tablet have a network connection?
Image analysis requires an internet connection. Check your connection and measure again.