Vpanin

I will be doing my brakes in a couple of weeks and I need to know

GRAND_LS 4

iTrader: (2)

If the pads seem to be worn evenly, you can get away with just replacing them. Just make sure you grease the shims.

But are the pads going out already at 24k?

Vpanin

26k now actually. That seems to be the story with these LS pads........They look like theyre about half way done...... just dont want the sensors to get scraped and light up my dash......and cost me 200 bucks.
I really need to know if anyone had any vibration, squeaking or any other problems without "bedding" the breaks after install

GeorgeT

Only if you want to maximize braking performance and avoid the possibility of "glazing" the new pads: if you do not break-in your new pads and have to come to an emergency high speed stop, you run the risk of glazing them and hving reduced braking power in the future.

I6turbo

iTrader: (1)

Right or wrong, I've never bedded new OEM pads on any "regular" vehicle like the LS. I always try to use the brakes very lightly for a while so that the wear pattern of the pad can conform to the rotor, especially if I don't replace the rotor. I've never had any issues doing it this way, but I can't prove that it's the best idea. I also make it a point never to do a hard/semi-hard stop and continue to hold my foot on the brake pedal without letting the vehicle continue to creep forward to prevent the pad from sitting clamped to a single spot on the rotor.

I do bed pads/rotors on high performance cars where the brakes may/will be used much more severely. Companies like StopTech that clearly know a thing or two about braking systems say that it's very important to do so. They also indicate that the procedure may vary by pad.

Here's their summary (more detailed info available on their site):
PROPER BREAK-IN OF ROTORS AND PADS IS CRITICAL. Not properly doing so can cause permanent damage to rotors and adversely effect overall brake performance. Pads and rotors interact with each other to provide efficient brake performance. The break-in or bed-in procedure is done to condition the pad/rotor interface. Depending on the pad used, more or less pad material is uniformly transferred onto the disc as a thin film. The resins and bonding agents in some pads need to be heat cycled to work properly as well. By not properly bedding in pads, uneven pad material deposits can occur that may cause a vibration. Improper wear characteristics may also show up on either the pads, or rotors, or both. Always follow the recommended break-in procedure for any pads, rotors or brake systems. This link is to the Technical page of our website. The article titled The "Warped" Brake Disc and other Myths of the Braking System has more details about the effect of the pad and rotor together

Read this. It might change your views on bedding, and other things such as "warped rotors."
http://www.stoptech.com/tech_info/wp...rakedisk.shtml

EDIT: Here's a very interesting excerpt from that interesting article linked above. I think I'm going to go out and bed the brakes that I just replaced a week or so ago on my GX470, and start bedding all brakes in the future, even on "regular" vehicles.

Excerpt copied from StopTech site:
Regardless of pad composition, if both disc and pad are not properly broken in, material transfer between the two materials can take place in a random fashion - resulting is uneven deposits and vibration under braking. Similarly, even if the brakes are properly broken, if, when they are very hot or following a single long stop from high speed, the brakes are kept applied after the vehicle comes to a complete stop it is possible to leave a telltale deposit behind that looks like the outline of a pad. This kind of deposit is called pad imprinting and looks like the pad was inked for printing like a stamp and then set on the disc face. It is possible to see the perfect outline of the pad on the disc. (FIGURE 5)

It gets worse. Cast iron is an alloy of iron and silicon in solution interspersed with particles of carbon. At elevated temperatures, inclusions of carbides begin to form in the matrix. In the case of the brake disk, any uneven deposits - standing proud of the disc surface - become hotter than the surrounding metal. Every time that the leading edge of one of the deposits rotates into contact with the pad, the local temperature increases. When this local temperature reaches around 1200 or 1300 degrees F. the cast iron under the deposit begins to transform into cementite (an iron carbide in which three atoms of iron combine with one atom of carbon). Cementite is very hard, very abrasive and is a poor heat sink. If severe use continues the system will enter a self-defeating spiral - the amount and depth of the cementite increases with increasing temperature and so does the brake roughness. Drat!

PREVENTION
There is only one way to prevent this sort of thing - following proper break in procedures for both pad and disc and use the correct pad for your driving style and conditions. All high performance after market discs and pads should come with both installation and break in instructions. The procedures are very similar between manufacturers. With respect to the pads, the bonding resins must be burned off relatively slowly to avoid both fade and uneven deposits. The procedure is several stops of increasing severity with a brief cooling period between them. After the last stop, the system should be allowed to cool to ambient temperature. Typically, a series of ten increasingly hard stops from 60mph to 5 mph with normal acceleration in between should get the job done for a high performance street pad. During pad or disc break-in, do not come to a complete stop, so plan where and when you do this procedure with care and concern for yourself and the safety of others. If you come to a complete stop before the break-in process is completed there is the chance for non-uniform pad material transfer or pad imprinting to take place and the results will be what the whole process is trying to avoid. Game over.

In terms of stop severity, an ABS active stop would typically be around 0.9 G’s and above, depending on the vehicle. What you want to do is stop at a rate around 0.7

to 0.9 G's. That is a deceleration rate near but below lock up or ABS intervention. You should begin to smell pads at the 5th to 7th stop and the smell should diminish before the last stop. A powdery gray area will become visible on the edge of the pad (actually the edge of the friction material in contact with the disc - not the backing plate) where the paint and resins of the pad are burning off. When the gray area on the edges of the pads are about 1/8" deep, the pad is bedded.

V8_Fan

With OEM pads, you can generally get away with braking lightly for the first few tanks of gas (just like when you buy a new car, they say to drive easy for the first 200-600 mi). This is not only to break in the engine/drivetrain, but also helps bed the brakes/rotors.

If you install performance pads, you'll need to bed the brakes, or braking will be marginal/terrible and can be downright dangerous (you can go off a mountain road). When I bedded the Porterfield R4s carbon pads and cryo rotors on my LX, the pads were literally smoking (resins burning off).

GRAND_LS 4

iTrader: (2)

i for some reason understood that as turning your rotors, i have no idea why.

Anyhow, its strongly recommended that you break in your pads. There are many procedures posted online, and i would take it easy the first couple of gas takes as well.

here is one i found:

http://www.tirerack.com/brakes/tech/....jsp?techid=85

Vpanin

I wonder if Lexus beds the brakes for you during manufacturing......or if the dealerships bed them when they install new brakes for you

StanVanDam

I changed all 4 pads myself a few months ago and didn't bed them in or resurface the rotors. I now have pedal+steering wheel vibration while braking and can see pad material imprinted on the rotors from a complete stop with warmed up brakes. Because of this, I recommend doing the bed-in procedure when changing pads.

My rotors are original and therefore have experienced 8 years of Canadian winters. Some salt corrosion may be a contributing factor to the vibration.

FYI 2002 LS430 rotor specs are:

OEM thickness 30.0mm, minimum 28.0mm, max runout 0.05mm
OEM thickness 16.0mm, minimum 14.5mm, max runout 0.05mm

Vpanin

It could be the age of your rotors. I went and did the pad change without rotor resurfacing or bedding. My brakes work fine. No vibration or squeeking.

allst4r

iTrader: (7)

i drive an is350 and i only bed in brakes when i get new rotors and pads. i dont bed in when i switch out the pads. not sure if this is the correct way.

Vpanin

I didnt do any bedding after switching the pads and im about to pass 10k miles on those pads.The Brakes are perfect!! no issues with not doing the bedding

mniehaus

I have been doing all my own repair for 38 yrs.
[B]Bed you brakes! I have learned the hard way. Some brakes are pre-sintered, but they are few. I had several new rotor and pad ruined (pulsing and pulling) before learning. Centric has a great explanation on their websit why you need to Bed your brakes!.

V8_Fan

Look at it this way, it only takes like 15 min to bed the brakes. I bedded my OEM LS pads on rotors w/ 25K miles. 7 months later, they are still perfectly true, and that's after some hard stops, too. Like I said before, the dealer replaced the pads on my LX during certification but didn't bed them. Within a year, they were pulsating, so I finally swapped out the rotors and pads for cryogenically frozen A.R.T.'s w/ porterfield R4s carbon/kevlar pads. Those pads definitely require bedding, or you'll have no braking power! After I bedded the pads, they were literally smoking! The pads on my LS didn't smoke. I believe if you drive on them easily for a few hundred miles w/ no hard stops, they'll be okay, but you are taking a chance by not bedding them.

I don't recommend resurfacing the rotors...you just lose more material, meaning they have more difficulty cooling and, hence, warp even faster. If your rotors start to pulsate, you need to replace both the rotor and pads together. Brakes aren't expensive if you DIY.