To Resurface Front Brake Rotors Or Not?

[lexguy2000]

My wife's 2000 LS400 squeaks pretty loud when braking. Lexus wants to replace the front pads, shim kit, fitment kit, and resurface the rotors ($280). I passed. I purchased the parts from Lexus and will have an independant shop install them. There is no pulsation from the brake pedal when I'm braking. Should I have the rotors resurfaced? I'd appreciate any knowledgeable input.

[VMF]

why not?

usually when you install new pads its good to have your rotors resurfaced. this will let pads have better grip on the rotor since all previous scratches are removed.

[Threadcutter]

My wife's 2000 LS400 squeaks pretty loud when braking. Lexus wants to replace the front pads, shim kit, fitment kit, and resurface the rotors ($280). I passed. I purchased the parts from Lexus and will have an independant shop install them. There is no pulsation from the brake pedal when I'm braking. Should I have the rotors resurfaced? I'd appreciate any knowledgeable input.

lexguy2000:

I agree with VMF; provided your Indie doesn't charge you an arm and a leg to re-surface them and they don't have to take a bunch of material off to get them true. Any more than about $50 for the pair on the high side is starting to approach the "ridiculous" category. It doesn't sound like they'd have to take much off at all because you don't have any pulsating, which is a good indicator of an out of round rotor. Remember, every time material is removed from the rotor, there is less "thermal mass" to absorb & dissapate the heat that is generated from braking. For a given amount of braking, the rotor with less thermal mass will get hotter than a rotor with more thermal mass. So, the rotor with less "meat" is more likely to warp under prolonged braking.

Most rotors have a number stamped/engraved on them which is the minimum thickness before the rotor manufacturer thinks you should toss it and install a new (thicker) one. Your Indie will in all likeliehood measure the thickness & compare that against the number on the rotor. If they tell you that you need new rotors, have them show you the measurement (better yet, ask to use their calipers) & you compare the measurement to the number. Conversely, purchased correctly, (NOT from the stealer) new rotors aren't terribly expensive (compared to a lot of other Lexus parts).

BTW:

I hope you don't mean the Stealer quoted you $280 to just re-surface the rotors...................If so, that qualifies for robbery.

[kcpth]

Most places i know resurfaces rotors for a ball park figure of $10 per rotor. So u have 4 = $40. If ur indie does the job... n asks u to replace it... make sure like wut Threadcutter mentioned... ask him to see the measurements. It's also imperative for him to clean the brake calipers n such. It's also a good idea to put some anti-seize on ur pins, shims, etc.

If u r a DIYer... go to

www.lexls.com

n check the tutorial section for changing brakes. If u have 2 vehicles... put them up on jack stands... bring it to b resurfaced. U can save some money... but expect to spend sometime on da project since ur taking off the rotors. But if ur not squeeze for money n dont want to go through that crap... bring it to ur indie or Toyota dealer.

Take care.

Tom

[sha4000]

if youtake the rotor off yourself and bring it to a machine shop youll pay between 5-$10 but if you take your car to the shop they will charge you like 80 bucks to resurface rotors in MY experience

[Kennyr]

Just put new Lexus pads on. Don't take any material off your rotors if your brakes don't pulse. And if they do just replace the rotors with aftermarket ones.

[VMF]

if youtake the rotor off yourself and bring it to a machine shop youll pay between 5-$10 but if you take your car to the shop they will charge you like 80 bucks to resurface rotors in MY experience

pulsating brakes does not mean that you need to do a costly rotor change. brakes pulsate because if you overheat them the pad material sticks to the rotors and makes the surface uneven. you DONT really bent the rotors. you CANT bent them, they would crack before they would bent. there is nothing wrong with resurfacing, just dont take a lot off. usually it costs around 10$ per rotor.

the only reasons to change the rotors would be when they are too slim or when you failed to replace the pads and scatched the hell out of them.

[monarch]

I agree with Kennyr - just install new Lexus pads and pray the Indie is competent enough to install the pad hardware correctly, including using the correct grease on the correct spots if specified in the factory service manual. If brakes squeal, something is usually wrong with the pad mounting hardware / installation.

The Lexus factory technician training service manual advises techs to replace rotors only if the runout exceeds a certain limit. In other words, don't replace or resurface rotors unless there is an excessive amount of pulsation felt when braking. Lexus rotors may also wear too thin, but normally not until the 3rd pad change.

[Shadow]

Skip the resurfacing and go directly to the pads. You won't notice a difference except for a heavier wallet.

[lexguy2000]

Skip the resurfacing and go directly to the pads. You won't notice a difference except for a heavier wallet.

I want to say thanks to all who posted to this question. I have yet to make up my mind on whether I'll instruct them to take a light surface cut on the front rotors, or just load the pads and install the applicable kits and hope for the best. I am concerned about the indie being knowledgeable about lubrication points as well as torque specs. Can anyone recommend a competent independant in the Orlando area? I'm sincerely grateful for all the input. Multiple heads are better than one!

[Toysrme]

lexguy2000 a lot of people like the rotors to be surfaced with new pads, but if they're not warped to begin with, it is easily skipped.

The big thing is breaking in pads &/or rotors whatever is new.

100 miles of very light, slow braking for pads

1,000 miles of very light, slow braking for new rotors

[92ls forhundo]

lexguy2000 a lot of people like the rotors to be surfaced with new pads, but if they're not warped to begin with, it is easily skipped.

The big thing is breaking in pads &/or rotors whatever is new.

100 miles of very light, slow braking for pads

1,000 miles of very light, slow braking for new rotors

for about a hundred bucks or so,you could just put new rotors on the fronts and start from scratch. I put new rotors on my LS aout 4 months ago tola price and labor was $130 bucks, maybe not oem parts, but better than what i had which was the pulsing thing. Google lexus/toyota parts and youll find some good prices for the parts.

[SRK]

I have done many brake jobs for customers over the years. If the rotors have no distortion and do not demonstrate any vibration under heavy braking, I don't turn them. I don't turn them even when the pad backing plate has touched down and produced a "small" amount of damage. If the pad has produced a large amount, then the owner deserves to pay a lot more for being stupid - new rotors go in.

If the rotor is warped and vibrates, I normally replace it with a HIGH quality new one - which means an OEM one in most cases, or Brembo or Raybestos in others.

I will only install high quality pads as well - which means an OEM set, or Raybetos Gold, or PBR.

What is most important, and something I rarely read on the tutorials here and on other sites, is to monitor the push back of the pistons in the caliper to determine if they need rebuilding. I judge the "feel" of the push back, and decide accordingly. Jamming a piston or two back and having them stick will cause all sorts of trouble, and quickly, usually concerning safety. Most don't discuss caliper overhauls because they aren't prepared to do them.

I never return a car to a customer unless, during at least a six mile test drive, I brake forcefully. When returned I never instruct the customer to "go easy" on the brakes, or "drive gently". Just drive the damn car as you would normally.

I don't get come-backs. No one has ever complained. My brake jobs always work.

[Toysrme]

I agree. $15 to turn a brake rotor. $55 for a set of Brembo Blanks...

But my point was that you don't *have* to do anything if they're not warped to begin with. I've never seen the point.

[nc211]

SRK, can you give me some advice on how to install a set of front pads so they're tightly seated in the caliper with out the fitment kit, so they don't move around when the motion of the car changes direction? Follow me? Like when I go in reverse and push the brakes the first time, the front pads shift and make a slight clanking noise. Then forward, first time on the brakes, and they shift forward and make that clank noise again. It's just one time, the first time in each direction, but it's annoying as hell.

thanks amigo!

[SRK]

Hi NC;

I know exactly the noise you speak of.

At each end of the caliper bracket opening that accepts the pads there must be a stainless spring/shim. This allows enough pad movement to prevent binding, and allows dampens the noise by taking up the clearance. Lexus calls them "pad support plates" and recommends that they are replaced with the pads. The shims should be available separately if they are not present on your caliper bracket. I have found over the years that some "mechanics" throw the shims away as they can make sliding the pads in a bit more difficult.

The pads on my LS click every now and then with forward and reverse stops, probably because I have not replaced them.

As to whether you can fashion some sort of shim to take up the clearance, and at the same time prevent binding, I don't know. That would be more difficult than purchasing the support plates I think.

SRK

[LexusLooker]

Guys, I'm going to throw out some advice without testing it first. I may be sorry and need to be :chairshot: .

I have the same change-direction clunk/pop that NC Robert has. I have the original pads and shims on the car. For somebody who said the shims didn't come with the pads, it's a separate part/kit. I think it was about $40 at the dealer...yikes. These shims fit parallel in layers with the pads. There are two per side. I'm not sure if this is what SRK is referring to or not.

The cause of the clunk of course is that the pads are slightly smaller than the slot they fit in. So they shift rapidly from front to back or vice-versa and clunk around. The shims I have wouldn't specifically buffer that action, and I didn't see anything that would take up the slack. I doubt the brakes had ever been touched, so I don't suspect anything is missing. Short story, I think others who have mentioned greasing the backs of the pads and the shims are on target. Greasing them will make the shift forward or backward "mooshier" and not cause a clunk. I took mine apart, found what looks like dried grease, cleaned everything thoroughly with brake cleaner (I would recommend new shims with new brakes though...I was just cleaning stuff up) and used a spray-on brake squeal quiet stuff. NOT THE CORRECT SOLUTION. It would probably fix the squeal if I had it, but it was sticky and just kinda glued everything together. So I still have the clunk. My theory is that if you grease (not glue) everything, you'll fix the problem. Of course, you can't use regular grease. I found some tiny packets of brake-specific grease at an Auto Zone that I want to try. Maybe Monarch can tell us where to apply it since I think he mentioned the service manual. At any rate, it goes on the back of the pads and probably between the two shims and then on the shim-to-caliper area. NEVER on the face of the pad. I'll try this next time I get in there, but best of luck to anyone who wants to try it!

James

[LScott400]

I'm with Threadcutter on this. I rarely machine my rotors because, as he said, I want as much mass as possible (short of replacement) for heat dissipation. However, if a lip has developed I machine them. Keep in mind as to rotor thickness that the number stamped in the rotor is a Discard specification. There is a separate Machine To spec that will allow enough margin for wear during the life of the fresh pads so that the rotor will theoretically not reach the Discard thickness until the pads are worn out.

Having said all that, the best pedal feel and least likelihood of brake noise will result from machining the rotors when a new set of pads are installed. It is very important that the rotor friction surface is completely cleaned of all machining residue. I also lightly file all 90 degree angles on the pad at a 45 degree angle to minimize noise potential while the new pads seat in to conform to the rotor. Calipers are likely to sit a few thousandths of an inch off from true vertical over the rotor. Clean, perfectly smooth, and freshly lubricated caliper slide bolts are also a necessity.

I am also a believer in gentle brake applications while the new pads seat in.

[nc211]

Thanks SRK, I know exactly what part you're talking about. Two shiny silver plates within the caliper housing for the pads, on the ends. My first set of replacement pads on the front, the mechanics did just as you said, they threw them away. I recently replaced them with a set of raybesto ceramics that had the shim kit, but not the fitment kit. However, they're completely quiet now, no more screaming squeeks. I'm finding that the clicking noise is fading a bit too. I think it's due to the heat expanding the pads within the housing? Whatever is causing the click to fade is fine by me! I'm freakin' broke now thanks to my tire fiasco!

Hi NC;

I know exactly the noise you speak of.

At each end of the caliper bracket opening that accepts the pads there must be a stainless spring/shim. This allows enough pad movement to prevent binding, and allows dampens the noise by taking up the clearance. Lexus calls them "pad support plates" and recommends that they are replaced with the pads. The shims should be available separately if they are not present on your caliper bracket. I have found over the years that some "mechanics" throw the shims away as they can make sliding the pads in a bit more difficult.

The pads on my LS click every now and then with forward and reverse stops, probably because I have not replaced them.

As to whether you can fashion some sort of shim to take up the clearance, and at the same time prevent binding, I don't know. That would be more difficult than purchasing the support plates I think.

SRK

[doorman]

Hello, I have a 2007 LS , The front rotors were always a problem. Cut under warranty. until the warranty ran out. I went to rock auto.com and bought a set of beck arnley rotors , they have 5000 miles so far and are good. I think lexus rotors may have a flaw. They were not hard to put on.

good luck

[90Duchess]

I agree with most posts, however, you'll be far better off if you have the rotors turned on the car, otherwise known as matched to the hub, as each wheel develops wear inconsistencies not perfectly matched with another wheel. In other words, taking all the rotors off and having them machined independently doesn't account for out-of-round measurements each one will have, all bolted together. Age, heat, and cooling all affect metal, and warpage will invariably result in the bearings, spindles, and rotors. Have them resurfaced on the vehicle and, proper brake job performed, you'll have brakes smooth as silk. Make a mark on each rotor in relation to each hub, and you'll be able to match each one up in the future if you ever need to disassemble them again. Hope this helps!

[SRK]

Are you speaking of axial or radial run-out?

Could you explain how bearings and spindles warp?

[90Duchess]

Are you speaking of axial or radial run-out?

Could you explain how bearings and spindles warp?

So sorry; bad sentence structure and poor editing skills on my part. I just assumed people would understand; my fault. My intention was to help, to point out that having rotors hub-matched (the technical jargon for the procedure, "radial run-out", escaped me at that point) is a far better option than just taking them all off, as some have suggested; having them lathed and putting them back on, irregardless of which hub they originated from. Yes, the high-heating and repeat-cooling of metal parts will cause warpage, or distortion. As parts age, this action is cumulative. Anything attached to an axle will experience these effects, whether simple wear of a rubber or plastic bushing; a metal backing plate, metal spindle on which mounts the bearing, caliper, rotor, and yes, even the wheel. As parts age, wear or abrate into their mating surfaces and become accustomed to their relations to each other, you should keep this knowledge in mind when evaluating issues with each axle as a unit, not as individual parts. If you want silky-smooth brakes, you should take into account radial run-out, even on brand-new rotors. They are machined to precise measurements on a lathe. Any mechanic worth his salt will tell you that they will not be perfect after mounting unless they are turned, or fine-tuned to each wheel. I was only trying to help, as I have had three import cars needing brake work over the years and found that when I needed to have the rotors turned, I was much happier having them machined on the car as opposed to off it. Hope it helps. Good luck!

[1990LS400]

90Duchess, on 29 Jun 2013 - 00:23, said:

My intention was to help, to point out that having rotors hub-matched (the technical jargon for the procedure, "radial run-out", escaped me at that point) is a far better option than just taking them all off, as some have suggested; having them lathed and putting them back on, irregardless of which hub they originated from.

Your posts are timely in that just last night when I picked up my car a Lexus dealer mechanic explained the same concepts to me using very similar language. He told me that he removes and machines rotors while off the car only in unusual circumstances and that the best results are obtained when the rotors are machined while on the car.

[SRK]

In the past certain models of cars had to have their brake discs machined on the car because removing them involved disturbing and possibly damaging the hub bearing. Honda had several models like that.

However removing discs that are easily dismounted is far preferable as it is faster, and the bench mounted brake lathes are more stable and rigid and produce better surface finishes. It is the industry standard to remove them.

If one is not familiar with machining practices and tolerances then it is difficult to imagine how accuracy is obtained. I am familiar. The arguments put forth for machining on the car do not hold up. Only the interface between the hub and the disc is important in terms of axial run-out. Radial run-out is not important. Bent or worn spindles, or steering gear, or backing plates have no influence. Suspension parts and wheels have no influence on how the disc turns. There are many factors other than the disc that can contribute to braking vibrations, but they must be corrected themselves - no amount of accuracy in a brake disc will compensate for a loose outer tie rod.

I've turned more than a few brake disc and drums. I have run several different brands of brake lathes. It's how I do it, and my repairs always work.

And no one has mentioned parallelism in brake discs - also very important, and best achieved in heavy rigid brake lathes with the disc dismounted.