Does anyone know if it is neccessary to remove the large nut in the center of the rotor to remove the rotor? The large nut is rusted so much I can’t tell if it needs to come off before the rotor will.
NO! The large nut holds the end of the CV shaft. You may find that your rotor is rusted to the hole in its own center where that big nut is. Have you removed caliper yet? Are in completely over your head here? You’re talking about brakes here. Botched brakes can kill you. DEAD!
yep caliper is off- I thought it might just be rusted on but I did not want to start banging on it until I was sure- I will spray it down with pb blaster over night- thanks for your help … off to find a big hammer!!
Note that you can hit it both directions to help get it off.
A recent study of preparations designed to combat rust in these situations found that a 50-50 mix of transmission fluid and acetone was the best. PB Blaster was third behind some brand I never heard of. I’ve been thinking about making up a batch to try it out.
It is rust on the hub that is holding it in. Try mechanically removing the rust from the sides of the hub and use plenty of lube. PB works but the tolerance between the hub and the rotor is a close fit so remove the rust there. Do not hammer but tap each side right and left and from behind if you can move the shield out of the way.
One method of last resort is to alternately heat the center part of the rotor (the part that is rusted to the wheel hub) with a propane torch and squirt the openings in the rotor (the lug nut bases, the barely visible line where the middle of the rotor seats) with liberal amounts of PB-Blaster. The idea is that as the rotor cools, it shrinks. It will tend to suck the PB-Blaster into the resulting gaps. It may be necessary to repeat this a number of times. Assuming that you plan to replace the rotor anyway, feel free to bash it occasionally with a big hammer.
Just in case you might ever need to do this again, slather anti-seize on the back of the new rotor, the mating wheel hub, the front of the new rotor where the wheel will contact it, and the mating surface on the wheel. (Keep the anti-seize off the braking surfaces of course).