It’s one thing to pop off the rotors, have them machined, and pop on some new pads on a car driven in sunny S. Cali, but still another to do that same operation on a Wisconsin car that spends 4-months a year being driven through a salty brine. Forget tapping the rotor a few times and having it fall off in your hands. As for the solution that requires the insertion of two 8x_ mm screws into the rotor and pressing them from the hub; you’ll most likely break the screws if you can get them past the rusty buildup in the tapped holes. Several solid blows from a mallet to the inner part of the rotor were necessary to break mine loose. Once separated from the hub, inspecting the meeting surfaces of both the rotor and hub will likely expose why so many of these cars have problems with vibration from the front wheels, which is felt through the steering wheel during braking. Post about this problem can be found in this forum and elsewhere. My rotors had a solid ring of scaly rust on both of the surfaces. This scale could be scraped and chiseled away, but still these surfaces could not be made flat and true as they were new. In addition, the shop that eventually machined my rotors sandblasted them, which made them look a bit nicer, but did little to repair that surface. If the surfaces are not square, i.e., perpendicular to the brake pads, there is a good chance that the rotors run-out spec of .010” will be exceeded. If the rotor can’t be mounted squarely on the lathe due to the scaly rust, they cannot be turned within spec. For this reason, Honda recommends that the rotors are machined ON THE CAR using an expensive tool for that purpose. My dealership offered to provide such a service and even slap some new pads on for a mere $270. I elected to buy Honda pads for $60---I know I could have gotten them online for $40, but shipping costs would have closed the gap to within 5 bucks---and pay a local shop to machine the rotors for $50. This shop was initially hesitant to machine the rotors, instead suggesting that I should buy a pair of Chinese knock-offs, claiming that they wouldn’t be able to take off enough material to remove all of the rust pits and scale. I asked them to try since the thinnest point on the rotor measured at .810” and the minimum spec is .750”. That employee later told me that he was surprised how well they came out. While I mentioned the effort involved in removing the rotors from the hubs, I’ve not yet mentioned another problem that these cars are prone to. The countersunk 6x_mm Phillips head screws that hold rotors on rarely come off without a fight here in the Rust Belt. After using various methods of enhanced interrogation on mine, I pulled out the drill and reluctantly drilled them out. Luckily, around 30-years ago I decided that I didn’t ever plan to own a car that used fractional hardware and bought a set of metric taps and dies. I was able to use one of those to chase the hub screws clean. Many people post that these screws are only necessary for assembly at the factory. My method for removing excessive run-out from the rotors requires the use of these screws. Luckily, my local hardware store had stainless steel versions of the screws with allen heads. Far superior to OEM.


Picture of New Stainless Screw

Curing excessive offset
First, I mounted my resurfaced rotors on the car and tightened the new stainless steel assembly screws. As I tightened these screws, I rapped the rotor between the studs in order to firmly seat it. Once well-seated, I set up a dial indicator as described in the Fit shop manual. My initial readings were .060” (6-times that minimum spec) on the driver’s side and .040” on the passenger side. Without fixing this problem, I would likely experience the shaky steering wheel that people often post about.


Picture of excessive run-out measurement
In order to bring the run-out into spec, I noted the location of the lowest point in the rotation and then removed the rotor again. Next, I placed a sort of half washer crudely fashioned out of .003” brass shim stock behind the stud closest to the low point, replaced the rotor and measured again. Note: if I had this to do again, I'd make a few of these washers cut them a bit neater. From this point, it is just a matter of trial and error: Remove or reposition shim stock (or add additional as necessary) until the run-out is less than .010”. For me, it only took three tries and 2-thicknesses of shim stock on each side. I can’t give any advice on where to find the shim stock as I got mine years ago from my father who worked as an automotive machinist. It does seem to be a hot topic on Google, though. [UPDATE] I just found this product while looking for a picture to use in this post: Brake Align As usual, Google dissolves the illusion that one has spawned an original thought.


Picture of shim in final placement and coated hub.

Before final assembly, I coated all of the screws and the mounting surface of the hub with Anti-Seize Compound. My hope is that the whole process will be much easier next time with the addition of the compound and the stainless steel allen head screws. In fact, I would suggest that anyone who has a car in an area where salt is applied to the roads and who can still get these screws loose perform an upgrade to the stainless screws in order to save some grief down the road.

 

Although I know its not completely necessary i change my rotors every time I do my breaks. They are cheap enough that I would rather have a fresh set. (I use good rotors as well. EBC slotted) your pads and rotors for a reasonably driven car are good for what? 3-4 years? Seems like I can afford >200 bucks every few years to be completely confident in my break system. That being said. Kragen/o'riely and other auto parts shops will turn your rotors for like 10-15 bucks in California. 50 is a bit steep. I would shop around for a more reasonable machine shop or something.

 

Kelsodeez, I will probably go with a cheaper shop next time turning is required. I had wanted to try this place out due to their good reputation. I now believe that no place could get them within the run-out spec given the rusty scale present.

 

I wish I understood the above better. I got that you drilled out the OEM screws. Then, you tapped the holes for a new size screw? Is that correct?

All in all, good post. I admire the effort and the outcome. However, I don't see anything about that rotor in the picture that is worth saving, and I would have bought new ones. But that's just me.

 

Next time around I will clean some new ones then paint with bbq paint (flat black) on the edges of the rotor to give it a clean look and protect it. While at it, powder coating the calipers would look nice, and avoid the sprayed brake dust coated look that most lazy tuners do,.

 

Marrk, The tapping part was strictly about cleaning out the remaining portion of the old screws. In the the end the screws were replaced with ones of the same thread size.

 

Understood. Thank you.

 

I will suggest to replace rotor securing screws with those having hex hole instead of fillips type screw (the BMW uses such screws; they are easier to remove with hex key) also it is a good idea to put anti-seize on the screw threads and cover the screw head with thick grease or silicone. I also put anti-sieze on the hub where rotor goes

 

Most mechanics I've talked to agree that you really don't even need said screws. I wouldn't bother to much with the details. You could likely throw them away completely and rely on your wheel to hold the rotor in place and be just fine.