Measuring Brake Pad wear

[HIe34]

Since most of you here are experts and I am ridiculously new to the DIY team, I'm hoping you can save me some research time. My brake lining light came on today so along with checking if the sensor is screwed up, I will check out the pads. I have not had any indication that they are wearing (no noise, car stops better than any car I've ever driven), but in checking them, what tool is best to measure the remaining life of the pad (a ruler?, I'm sure it's a bit more complex).

And with that measurement, how do i determine whether or not to replace? Unless of course it is so obvious when i look at them.

Mahalo

[BigKriss]

When the pad thickness is the same or lower as the backing plate thickness, I would start to consider replacing them. Its not more complex by just visually inspecting them. You don't want a situation where the brake lining is all gone and the backing plate is touching the rotor.

[HIe34]

Thanks BigKriss. Just eyeball it then; no special measuring sticks.

I was thinking about painting the calipers. Not sure though, can't make up my mind if it's lame or if I would like it. My car is white, like yours, and the most popular color seems to be red which I definetily don't want. If I do, and i think there is an article on Pelican, what type of paint should I use; and how long before putting them back on for street use?


When the pad thickness is the same or lower as the backing plate thickness, I would start to consider replacing them. Its not more complex by just visually inspecting them. You don't want a situation where the brake lining is all gone and the backing plate is touching the rotor.

[Qube]

Silver. Classy. I tried blue and have yellow. I now firmly believe a NICE silver is the best you can do.

[HIe34]

Any particular brand/type of paint? Something Home Depot carries or is there a special "caliper paint"?


Silver. Classy. I tried blue and have yellow. I now firmly believe a NICE silver is the best you can do.

[BillionPa]

dont paint them, have them nickel plated!!!

and if you paint them, you do need caliper paint. its ceramic based and wont burn on the surface of the caliper.

if you are removing the calipers, you should get brass bushings to replace the guide pins, rebuild the piston seals, and bleed the system with DOT4

[Bill R.]

can use a ruler to measure it or a dial caliper or a depth mike. This 2mm does not include the backing plate on the pad, only the pad material itself





Since most of you here are experts and I am ridiculously new to the DIY team, I'm hoping you can save me some research time. My brake lining light came on today so along with checking if the sensor is screwed up, I will check out the pads. I have not had any indication that they are wearing (no noise, car stops better than any car I've ever driven), but in checking them, what tool is best to measure the remaining life of the pad (a ruler?, I'm sure it's a bit more complex).

And with that measurement, how do i determine whether or not to replace? Unless of course it is so obvious when i look at them.

Mahalo

[BigKriss]

I have painted some calipers already. I used VHT flameproof coating - the colour is flat alumium. the can is 11oz and can easily do 4 calipers. you have to remove the caliper, clean it throughly, apply some acetone to clean it, put several paint coats on the caliper and then cure it in an oven over 2 hours slowly increasing heat. There are instructions on the can. I can't say how well the paint hold up - I haven't installed the caliper yet. I like silver cause it looks stock also.
http://img88.imageshack.us/img88/5213/pict0053medium7xd.jpg
http://img214.imageshack.us/img214/5369/pict0054medium1ot.jpg

[HIe34]

Thank you Bill, exactly what I needed.



can use a ruler to measure it or a dial caliper or a depth mike. This 2mm does not include the backing plate on the pad, only the pad material itself

[Bill R.]

ones who claim to want function over form. There are a number of plating processes out there that improve the ability of an object to dissipate heat. There's a black nickel that comes to mind specifically for this. Most paints and ceramic paints tend to act to some degree as insulators , along with a number of plating processes. When you paint the calipers with either powder coating, or any other paint, your going to affect its ability to shed heat, Same thing applies to painting rotor hats and the outer finned edge of the rotor as well. So in your never ending quest for bling, you may have a detrimental effect on the new big brakes that you're putting on. Granted it won't be a huge difference but it is a difference, I don't know if anybody has actually done any research to determine how much effect this has or not.

[chris_e34]

one more resource for you

http://www.bmwe34.net/e34main/upgrade/Paint_callipers.htm

[Anthony (M5 in Calgary)]

can use a ruler to measure it or a dial caliper or a depth mike. This 2mm does not include the backing plate on the pad, only the pad material itself

Cripes, 2MM is less than 0.080" - well thinner than the backing plate. I've got years left on mine. :)

[BigKriss]

I've never heard of black nikel plating before Bill, can you give us a link. Is this what you would do if you were to put rebuilt calipers on your car?


ones who claim to want function over form. There are a number of plating processes out there that improve the ability of an object to dissipate heat. There's a black nickel that comes to mind specifically for this. Most paints and ceramic paints tend to act to some degree as insulators , along with a number of plating processes. When you paint the calipers with either powder coating, or any other paint, your going to affect its ability to shed heat, Same thing applies to painting rotor hats and the outer finned edge of the rotor as well. So in your never ending quest for bling, you may have a detrimental effect on the new big brakes that you're putting on. Granted it won't be a huge difference but it is a difference, I don't know if anybody has actually done any research to determine how much effect this has or not.

[Bill R.]

will be familiar with the process, its frequently used as a thin protective plating to help increase an objects ability to dissipate heat. The electronics industry uses it frequently.
I personally am too cheap to do anything like this. This was for those people going to the nth degree. If i put rebuilt calipers on my car , dissipation would be my prime concern, not appearance. So if it was aluminum I would glass bead the outside surface with a fairly coarse grit to increase the surface area and improve heat dissipation and leave it a plain aluminum finish. If it were iron or steel calipers i would either use a very thin coat of ultra flat black paint or just a coating of stove black, either of which would have the least effect on the surface as far as retaining heat. I would never paint the hats on the rotors since the plain iron would transfer heat better. To some degree the wheels themselves might act as heat sinks for the rotors in addition to the vented castings on the rotors themselves. So by not putting a coating inbetween the rotor hat and the wheel and hub you may help heat dissipation to some small degree. This is probably splitting hairs but why bother going to these big rotors and large calipers and then painting them all up to retain heat?





I've never heard of black nikel plating before Bill, can you give us a link. Is this what you would do if you were to put rebuilt calipers on your car?

[BigKriss]

Thanks Bill.


will be familiar with the process, its frequently used as a thin protective plating to help increase an objects ability to dissipate heat. The electronics industry uses it frequently.
I personally am too cheap to do anything like this. This was for those people going to the nth degree. If i put rebuilt calipers on my car , dissipation would be my prime concern, not appearance. So if it was aluminum I would glass bead the outside surface with a fairly coarse grit to increase the surface area and improve heat dissipation and leave it a plain aluminum finish. If it were iron or steel calipers i would either use a very thin coat of ultra flat black paint or just a coating of stove black, either of which would have the least effect on the surface as far as retaining heat. I would never paint the hats on the rotors since the plain iron would transfer heat better. To some degree the wheels themselves might act as heat sinks for the rotors in addition to the vented castings on the rotors themselves. So by not putting a coating inbetween the rotor hat and the wheel and hub you may help heat dissipation to some small degree. This is probably splitting hairs but why bother going to these big rotors and large calipers and then painting them all up to retain heat?