Instrument to measure braking performance?

Is there a gadget for automobile brake testing, an instrument of some kind I could bolt to my vehicle to measure the braking performance and get a numeric output? It would presumably measure the deceleration on full braking.

Sure enough is…

Your smartphone can do that with an app if you have one.


Some vehicles have a G-force meter in the instrument cluster.

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I doubt George’s ancient Toyota has one… and his totally analog truck certainly doesn’t :smile:


Here’s an analog g-force meter George can install on his rear view mirror:


I saw a lot of analog g-force meters and cracked from the inside windshields during the pet rock era

Pull that long tape measure out of your toolbox and measure the stopping distance after refurbishing the brakes, including bleeding them. That’s your baseline. Then occasionally make the same measurement to check for deterioration.


Keep in mind that that any measurement is a combination of the tires, brake balance and brake effectiveness.

Poor tires will limit your stopping performance. Poor front-rear balance will limit your stopping performance. The temperature of the brake linings or pads will also affect your performance especially the 4 wheel drums on your truck.

Good tires, good balance and good brakes should give you maybe 0.7Gs in the truck, 0.9Gs or better in the Toyo. Any modern car should throw down 1.0Gs or better. Some much better!


Budget upgrade ideas for the old truck-



Just don’t do what this guy did.



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+1. Most excellent solution, tag awarded to @asemaster . Further proof that simple is best.

And that gives you a numeric output how??

:rofl: Didn’t think about that… :grin:

Yeah sure I can be a little anal about some stuff, but the instrument I use is my foot.

There is a GPS toolset app for Android that measures speed variations using GPS.

Care to share a link??

I supposed you could use accelerometers.

My brother did that to my previous Camry. I was mad at first but eventually I started to like it. Sadly, the paint came off due to heat.

The brake pads rubbed the paint from the inside of the rotor ( which was the plan ) and left the back of the rotor colored. It was really cool.

Never had any issues.

I’ll post a picture of it if i find the photo.