2006 Z51 Rotors

[Harry S.]

Time to clean out the brake dust from the drilled rotors. Before I pull the wheels and start measuring, anyone have the diameter of the drilled holes in inches or mm. Trying to find a metal bore brush that size is turning out to be more difficult that I figured.

Thanks

[Ed H.]

Re: 2006 Z51 Rotors

Harry l have set of small drill bits both mm and standard got them at Harbor Freight. There are 20 or so cheap.

[David M.]

Re: 2006 Z51 Rotors

Drill bit not a bad idea. Rotary wire pipe brush may work too. Either on a Dremmel or a cordless drill.
Hunt around on McMaster Carr. They will have it and it'll be delivered to your door in a day.

https://www.mcmaster.com/products/wire-brush-bits/

[Richard M.]

Re: 2006 Z51 Rotors

Harry, In prep for the regional on my Z51 original rotors, I had the same concern about the brake dust in the holes. It's hard as a rock.

I used a old small diameter screwdriver with a ground off pointed tip I had in my tool collection. I simply pushed and twisted each and every hole on all 4 rotors.

The material is very hard and caked inside the holes. And of course, there is a hole on both the inside and outside of each rotor surface. A brush is not going to work. You either have to drill them out or use a modified push tool with a handle like I did to clean the holes.

I had the car on my lift, all wheels removed. I set the transmission in neutral before raising it.(for the rears). I put a witness mark on the rotor(black marker), then I just punched through the holes as I turned the rotor around to my witness mark to make sure I got all of them.

There are about 640 rotor holes on a Z51. So it'll take a while to do this task.
Front: ~32 rows of 3, each rotor side. Rear: ~32 rows of 2, each rotor side.
(Did I really just go out and count rotor holes? Geesh I gotta be a real car nut to do this stuff!)

Rich

[Harry S.]

Re: 2006 Z51 Rotors

Measured them this morning. 3.5mm or 9/64 drill bit. I pushed the bit through by hand on 5 holes, easy enough. Not bad, 635 to go, decided not to use any power tools, just hand tools.

[Ed H.]

Re: 2006 Z51 Rotors

Rich, I used a carbide drill bit in an air operated drill unit that fits my small hands, it took half a day to finish but the residue was substantial. Wear a mask as the powder will chock you. Used a shop vac to remove the dust on the garage floor and around the area of the A arms. This will increase the effectiveness of your breaking. My 07 has 66K when it passed the ABS breaking test Pete required. When you hit the breaks at 35 0r 40 MPH you have to use all the power your right leg can exert, then Pete will smile. One more thing, test the hard breaking in your area prior to the on cite test, then check your LTP on your Dash gauge to insure you don't show (0) pressure. If that occurs you will need an accurate tire gauge and a portable compressor to insure you meet the 15 minute rule. I'm speaking from experience in Las Vegas, I made Pete smile again when it finally passed. May the NCRS gods be with you.