My Prius is Magic!

LOL, the real magic is 'dealer service' those oxy-morons

 

I can take three readings with a tread depth gauge in as nearly the same spot as possible and get three different readings. Also, the depth in the middle will probably be a little different from the edges and the edges from each other. So where the tech measures will also have an effect.

 

Stretches credulity:

Fronts, when new:


Rears, when new:

 

But jerrymildred you live in the real world (not just the Priuschat world).

 

I measure my pads and micrometer my rotors at every tire rotation. I take every measurement myself, using the same instruments, consistently.

And even I have occasionally written down figures that show a rotor "growing" (on the order of microns) between one tire rotation and the next.

Clearly, I'm just not controlling perfectly for everything, like the exact spot on the rotor where I measure, and the temperature of the rotor and the tool.

Throw in different technicians measuring at different times and different positions using different tools, and even more magic happens.

 

For pad depth I use a tread depth tool, works well.

 

How much precision is really needed with brake pads? It doesn't take much more than an eyeball check to tell you if one set is wearing faster than the others. Precise measurements with dial calipers or micrometers just tend to generate worry. A ruler with mm markings is more than good enough for me.

 

Well, the key factor is the minimum pad thickness...
As long as not down to 1mm, it's safe to say you have plenty of pads left! LOL

Posted via the PriusChat mobile app.

 

Jerry; you can still see millimeter marking on a ruler??? LoL I gotta grab the magnifying glasses nowadays.. LoL

I just eyeball them, though I do admit - I haven't replaced pads in over a decade. The car either gets wrecked or sold; before I get to do brakes. I did the front wheel bearing assembly replacement on my GMC truck last weekend and blew the dust off my caliber compression kit. The pads was only 50% worn.

 

It's also usable to generate plots. Plot the thickness numbers against miles, project that out to where it intersects the minimum, and say "I budget for a new set of pads at around that mileage."

Still necessary to keep checking, because some issue could have developed causing something to wear faster, but it's a fun exercise to see roughly what and when one is budgeting for.

 

Yeah, a bit past 90K kms, both the fronts and rears are down to around 6 mm remaining, on our. At that rate of wear, and considering they were all about 10 when new, they'll be down to 2 mm by 180K kms, if we ever get there.

My "comfort level" is around 3 mm remaining, regardless of the 1 mm minimum spec: I'd replace if I'd gone to the bother of removing and saw that. Bit of a walk but not that far, to our dealership.

 

You didn't actually expect quality work for something that was offered for free, right? That's why I'm always highly skeptical of their FREE X-point inspections.

 

For gauging pad thickness this is the go-to:



You can whittle yourself a set, from some old popsicle sticks. So far I've done one:


Finished the set, 3 should be enuf. Note that even 4mm is getting pretty puny, for brake pads:

 

Sure. That “free” service didn’t cost you anything. Neither did the tires either, right?

 

You realize that wood popsicle sticks absorb moisture and swell, right? , WAIT!! I forgot this is the Prius Chat universe, (sorry about that).

 

Do you realize how trivial that is, with brake pad thickness. I was a draftsman (and checker) for a lotta years, and degrees of accuracy is always something to keep in mind. Say concrete placement, structural steel, machine shop: all have difference tolerances.

I've got a dial indicator, a micrometer, a caliper (measured the wood bits with the latter), steel mm ruler, but round mm's is more than close enuf for brake pad thickness. Notice I don't even bother with odd mm's? 4, 6 and 8 is close enuf.