Front pad lifespan.

[texkid]

Reaching 30,000 miles and the mechanic says the shoes and pads still look new. Only had to turn the front rotors at about 20,000 miles (roughly).

[supmet]

Originally Posted by texkid

Reaching 30,000 miles and the mechanic says the shoes and pads still look new. Only had to turn the front rotors at about 20,000 miles (roughly).

How can the pads look like new if you already had to turn your front rotors?

[o89canucks]

Originally Posted by supmet

How can the pads look like new if you already had to turn your front rotors?

The rotors can still get warped or glaze over without wearing much of the actual pad surface off.

[Yaris Hilton]

Originally Posted by o89canucks

The rotors can still get warped or glaze over without wearing much of the actual pad surface off.

It's pretty much unheard of for disk brake rotors to actually warp. They get irregular patches of brake pad material deposited on the surface when used hard, especially if left with the pads in stationary contact with them while hot (i.e., the car's stopped for a bit after making a hard panic stop), and that makes the car shudder and pedal pulsate. Turning the rotor takes that off and gives a clean new surface, but they may also clean up with gentle normal use for a while, or with vigorous cleaning.

[1stToyota]

Originally Posted by Yaris Hilton

It's pretty much unheard of for disk brake rotors to actually warp. They get irregular patches of brake pad material deposited on the surface when used hard, especially if left with the pads in stationary contact with them while hot (i.e., the car's stopped for a bit after making a hard panic stop), and that makes the car shudder and pedal pulsate. Turning the rotor takes that off and gives a clean new surface, but they may also clean up with gentle normal use for a while, or with vigorous cleaning.

I don't know. I've turned lots of rotors over the years and what I see is runout and warpage (as in making two or three passes and still only removing metal at...let's say 12 o'clock, outboard, and 7 o'clock, inboard, for example). Now's the best time to see warped rotors because they're made so thin to save weight that they're usually below machine minimum (not discard thickness) after using up 1 set of pads.

[o89canucks]

Originally Posted by Yaris Hilton

It's pretty much unheard of for disk brake rotors to actually warp. They get irregular patches of brake pad material deposited on the surface when used hard, especially if left with the pads in stationary contact with them while hot (i.e., the car's stopped for a bit after making a hard panic stop), and that makes the car shudder and pedal pulsate. Turning the rotor takes that off and gives a clean new surface, but they may also clean up with gentle normal use for a while, or with vigorous cleaning.

Who told you that pile of garbage???

I have resurfaced a lot of rotors and you can definetly tell that a rotor has lateral runout when it is on the brake lathe. Take a hot rotor and drive through a puddle or snow and it is like taking a hot pan off the stove and pouring cold water into it from the sink. I have even seen the lateral runout be so bad (most common in Mitsubishi's) that the steering wheel will have a shimmy while the brakes aren't applied.

The clamping force of the pads against the rotor is so stong that even if your theory of "brake pad deposits" had any truth to it, the "brake pad deposits" would be removed the very next time that you braked.

I guess flywheels never get hotspots in them either or warp out and never need to be resurfaced either if this theory were true?

[Yaris Hilton]

There are lots of other experienced mechanics who'd disagree with you on those points. I'll cite this reference:
http://www.stoptech.com/tech_info/wp...rakedisk.shtml

[1stToyota]

While pads do a fine job at removing rust they're not cutting bits for removing large amounts of iron, and holding steady pressure on a stomped pedal isn't the same as locking bits down in place on a lathe.

[o89canucks]

Originally Posted by Yaris Hilton

There are lots of other experienced mechanics who'd disagree with you on those points. I'll cite this reference:
http://www.stoptech.com/tech_info/wp...rakedisk.shtml

If I remember correctly, this post was about longevity of the front brake pads, not on if rotors warp or not.

and for the stoptech garbage, you don't believe all the crap you read on the internet, do you?

[WolfWings]

Originally Posted by o89canucks

I have even seen the lateral runout be so bad (most common in Mitsubishi's) that the steering wheel will have a shimmy while the brakes aren't applied.

Oh gods, this, right here, and frying alternators so often most folks with this car I know keep a spare one in the trunk and can change it in under five minutes, are the two things I don't miss at all about owning a DSM Eclipse.

Being able to run up to triples in 3rd gear though was always nice, since mine was the FWD model. Muscle cars hate it when you just cruise past them frantically mashing their shifter up and down while you keep both hands on the steering wheel, thinking an automatic just beat them. Nah, just good gearing.

As for the brake pads: 45k here, they still look almost new, rotors and shoes too. I engine-brake as much as I can though, I'll admit, to the point friends always insist I ride at the rear of convoy's because I never give any visual warning of my speed to those behind me.

[bronsin]

Originally Posted by o89canucks

Who told you that pile of garbage???

I have resurfaced a lot of rotors and you can definetly tell that a rotor has lateral runout when it is on the brake lathe. Take a hot rotor and drive through a puddle or snow and it is like taking a hot pan off the stove and pouring cold water into it from the sink. I have even seen the lateral runout be so bad (most common in Mitsubishi's) that the steering wheel will have a shimmy while the brakes aren't applied.

The clamping force of the pads against the rotor is so stong that even if your theory of "brake pad deposits" had any truth to it, the "brake pad deposits" would be removed the very next time that you braked.

I guess flywheels never get hotspots in them either or warp out and never need to be resurfaced either if this theory were true?

Lets put it this way:


MY rotors never warp.


Nor the flywheel.

["G"]

I have seen them warp from over tightening lug nuts or incorrectly torquing them.