Brake Rotor Install Questions - Runout Measurement?

I've got a set of EBC Sport slotted/dimpled rotors ready to go in my truck. I should be able to swap rotors no problem - I've taken calipers off before, just haven't actually gone through the process of changing a rotor.

The warnings on the box are dire...it says that I should check for runout after mounting the rotors and that I should rotate the rotor by 1 lug on the hub if the runout exceeds 0.003" and measure again. It warns of violent juddering after 3-4000mi if this isn't done.

For those of you who swapped rotors, is this really necessary or should I slap them on and worry about judder/lathing later if it comes?

http://www.ebcbrakes.com/automotive...t_rotors/ebc_premium_replacement_rotors.shtml

 

Let me know how the new rotors are. I'm thinking of buying them myself.

 

90 percent of technicians do NOT check runout when replacing rotors, so you don't have to worry about it. If it were my truck, I would just slam them on, and I'm a master ASE technician!
Put them on and good luck.

 

X2

 

Thanks for the info guys! MaxTaco, Asgard, I'll post again when I get the rotors on! Was supposed to happen today but I wussed out and made excuses. Next chance will be Monday

 

Just kidding

What pads are you putting on with your new rotors?

 

Hawk HPS. I have them on my truck now but I got a pair of new ones to go w/ new rotors. I did my initial brake mods all at once (Goodridge SS lines & Hawk HPS Pads), so I don't know what difference the pads themselves make on this truck. They did make a small improvement when I went from stock to HPS on my 350Z though.

 

Lol you guys are putting a lot of pressure on me here I'll let you know. I'm not expecting any drastic changes in how the brakes grab but I'm hoping for at least a small but noticeable improvement in grab over stock rotors.

 

Just put 'em on.....torque the lug nuts properly and proceed with an appropriate 'bedding' process.

http://www.zeckhausen.com/bedding_in_brakes.htm

 

EBC Sport Rotors are on! This is the first time I've changed rotors and I learned some things;

Check that you put the memory card into your digital camera before you leave the house so you can write a useful how-to instead of a narrative that no one will read.

The 10mm bolt that holds the brake line to the spindle must come off. This will let you move the caliper around with the flexible part of the brake line.

There are 2 17mm bolts that hold the caliper to the hub. They are on the back of the caliper and are on bitch tight. I used an electric impact w/ a swivel joint, though there is enough room to use a socket and breaker bar, if you have a 3" extension.

The rotors were stuck to the hub. I got them off by spraying PB Blaster (Liquid Wrench) into the holes where the lugs are and the two threaded openings in the rotors.

I'm assuming that if you had the right size bolt, you could thread them into the rotor and use it to press the rotor off the hub. I didn't have these, so I rotated and tapped the rotor hat several times with a hammer.

I did not want to bang on the back of the rotor face with a hammer. Instead, I removed the brake pads and put the calipers back on the hub. Then I used a c-clamp pressed against a lip on the outside face of the caliper, between the two pistons, and the back of the rotor. A little pressure broke the seal and I was able to turn the rotor to the other side and use the c-clamp again. Once both sides were out I was able to remove the caliper and wiggle the rotor off the hub.

I put the new rotor on and then used the lug nuts to press the rotor onto the hub. No major torque here, just enough to set it in.

After I braked a few times I got this single loud bang. I remembered that the holes in the rotor hat for the studs allowed for a good bit of free play. I remembered the studs were offset on one side of the openings in the stock rotor. I'm thinking that when I braked, the rotor rotated on the hub until the leading edge of the hole set on the studs.

I haven't fully bedded these brakes in, but so far I feel a tiny bit more initial bite. I also get a nifty 'gzzzzzz' sound when I slow down, but I could only hear it with the windows down when I was driving between the aisles of my storage facility. My motorcycle does the same thing and it must be because of the dimples and slots in the rotor.

Remember that I went from Hawk HPS pads on stock rotors w/ Goodridge SS lines and then added the EBC rotors and new HPS pads, so your results may be different depending on what you're running.