Brake disc markings
Thread Starter
Burning Brakes
Joined: Sep 2017
Posts: 1,075
Likes: 65
From: Belgium
Brake disc markings
Hi everyone
I got another problem here. When cleaning the very rusty rear brake discs. I removed the markings 'LH' & 'RH'.
I got no photo's...
Does it matter which one goes left and right?
Do you guys have any recommendations on what to do now? (the discs are still in good condition)
I got another problem here. When cleaning the very rusty rear brake discs. I removed the markings 'LH' & 'RH'.
I got no photo's...
Does it matter which one goes left and right?
Do you guys have any recommendations on what to do now? (the discs are still in good condition)
Melting Slicks
Joined: Nov 2006
Posts: 3,415
Likes: 1,824
From: Apple Valley, MN
It does matter very much as the runout of the disc is affected if installed on another hub.
Finish cleaning them up, then install one and measure the runout. The more runout you have, the greater the chance for having air pumped into the brake lines due to the constant motion of the brake pistons. You will see a lot of opinions on how much runout is acceptable but IMHO anything less than 0.002” should be fine. If you have more, try the other rotor. Note that the rear rotors have extra holes in the flange to permit access to the brake adjusters so pay attention to that. Be sure that the mating surfaces of the rotor and hub are spotless and torque the rotors (all 5 lugs) before measuring the runout.
You can cut shimstock and selective place between the rotor and hub to achieve the desired outcome.
Finish cleaning them up, then install one and measure the runout. The more runout you have, the greater the chance for having air pumped into the brake lines due to the constant motion of the brake pistons. You will see a lot of opinions on how much runout is acceptable but IMHO anything less than 0.002” should be fine. If you have more, try the other rotor. Note that the rear rotors have extra holes in the flange to permit access to the brake adjusters so pay attention to that. Be sure that the mating surfaces of the rotor and hub are spotless and torque the rotors (all 5 lugs) before measuring the runout.
You can cut shimstock and selective place between the rotor and hub to achieve the desired outcome.
