Dan's Brake Thread

[bordin34]

Should I get my rotors cut? I am in the process of replacing the master cylinder, calipers, pads, and all rubber hoses. IS there a general rule of thumb about when they should be cut?

[The70RT]

You mean turned right? I would do it when the outer edge is noticibly thicker than the mating surface unless you have grooves or warping. Most garages do it everytime for extra money or they want to make sure the customer doesn't come back on the job they just did. If you were doing it on a car with cheaper rotors sure get them turned or replace them. These rotors on Chargers are not cheap. 80-120 last I checked. Dodge Dakota 30 bucks. Dodge neon 15.

[resq302]

I would have them machined / turned / cut (whatever you want to call it)  for a couple of reasons.  First, anytime I put new pads on, I get them machined so the pads do not wear unevenly or get a premature groove in them.  Plus it also makes for better braking performance.  Secondly, it looks like there is either grooves worn into them or that you have glazing on the rotor.  Glazing is mirror-like reflection on the rotor caused by the heat and metal being worn smooth.  A glazed rotor will not stop a car that well.  Imagine trying to hold onto a nicely waxed car, well, that is the same thing your pads will be doing to a glazed rotor.  Finally, machining the rotors will remove any slight warpage that you might have. Granted, making the rotor thinner will add to it possibly warping, but the amount they take off ususally will not contribute significantly to excessive warping or pedal pulsation.  If your brake pedal pulsates when you hit the brakes, (like getting a foot massage) then chances are your rotors are warped and need to be machined.

The scary thing is that most dealerships or service places do not cut or machine rotors and drums anymore.  They would rather charge you the extra money to replace them instead of cutting and resurfacing the old salvageable drum or rotor.

For what its worth, if it was my car, I'd have them resurfaced and throw a new set of pads on there.  Also, while you have the rotors off, pull the bearings and inspect them and pack them with some new grease.  A little preventative maintenance now will save you a lot down the road.

[bordin34]

Thanks, I will call around and ask how much places are charging.

[resq302]

I want to say they are about $15-20 per rotor to be machined, or at least they used to be.

[Steve P.]

Always resurface the drums or rotors when replacing the shoes or pads.. New surface to new surface. You want ALL the contact surface you can get and you damn sure don't want to put new brake material against a glazed steel surface.

[rt green]

have them measured. there is a minum spec. if you are going to keep the car, new is always best. brakes are not the place to be worried about saving a buck or 2.

[bordin34]

Today I removed both calipers and disconnected the hoses. I think I need new wheel bearing because if I grab to top and bottom of the caliper and pull and push hard I can hear/feel slight movement. Tonight I am going to remove the calipers and Master Cylinder.

[The70RT]

Today I removed both calipers and disconnected the hoses. I think I need new wheel bearing because if I grab to top and bottom of the caliper and pull and push hard I can hear/feel slight movement. Tonight I am going to remove the calipers and Master Cylinder.

I would clean the bearings with solvent & inspect them, but the play is adjusted with the nut that holds the rotor on.

[bordin34]

Does anybody know which way the copper washers go on the calipers? Do they go rounded side toward the hose or flat side toward the hose.

[bordin34]

Here are some pictures







And some pictures of when the front clip was replaced a couple owners ago.

[bordin34]

I took the rotors off the spindles today. My only problem is getting the inner wheel bearing out of the rotors. I can't seem to get the seals out and they are blocking the bearing.

[Steve P.]

This is easier than you will think.

With the dust cover, cotter pin and nut removed from the disc hub and spindle, slide the rotor toward you and remove the outer bearing. Now slide the rotor back onto the spindle and replace the spindle nut threading the nut on by about 3 turns. Now just grip the rotor and pull it toward you with some force. This will press the inner bearing and seal off the hub.

To install the  bearing and new seal you will grease the bearings and install the seal by tapping it into the hub in a circular motion. Just lite taps. You can also use a small block of wood between the seal and hammer. Tap the seal until it is flat with the back of the hub. Just a touch of grease on the seal and you are ready to reinstall the works.

Another way is to use a large socket that has an outside diameter just smaller than the outside diameter of the seal.

[terrible one]

So did you end up getting new rotors? With new calipers, pads, and hoses going on, I would go ahead and spring for them if I were you. I used '73 Charger discs on my '68 and can't remember them being very expensive at all . . .

[bordin34]

I am going to see if I can get mine cut and if I cannot I will be getting new ones. They seem to run about $50 each new.

[bordin34]

I tried that way and couldn't get it out. I didn't pull as hard as I could either.

[Steve P.]

Try it again.. It WILL work...

Then again those rotors look like crap.  Try to find rotors made in CANADA.. They are better steel than the junk from over seas..

[The70RT]

Not a problem. Get a hammer and use the handle part. Stick through the rotor in an angle till it hits the bearing and use another hammer and one easy hit and it falls right out with the seal......done deal.

[bordin34]

Thanks, wow that was really easy. I had both out in less than a minute.

[The70RT]

Thanks, wow that was really easy. I had both out in less than a minute.

[bordin34]

I am taking my time on this and have yet another question. Should I get new wheel bearings, the ones I have now look fine and I don't see any cracking or similar stuff. The only thing I see weird with them is I am wiggle them between the races, if that makes any sense. If that is normal, would I be fine to just repack these?

[The70RT]

I am taking my time on this and have yet another question. Should I get new wheel bearings, the ones I have now look fine and I don't see any cracking or similar stuff. The only thing I see weird with them is I am wiggle them between the races, if that makes any sense. If that is normal, would I be fine to just repack these?

You need to clean them in solvent to inspect them for any pitting on the rollers or race. If not they are good to go. New ones are like 20 for 4 if you decide to go that route.

[Steve P.]

If you have a wiggle between your spindle and rotors the bearings are not adjusted properly. There will always be a slight space between the bearings and races, but it should be too slight to ever feel by hand. With a dial indicator you should only see a few thousandths.

Clean and inspect your bearings. If they are good you can reuse them. Just make sure the races are properly set into the rotor. I have seen people end up with too much play in the bearings due to NOT setting the races to full seat.

A good book on doing brakes and bearings should be your next purchase. Remember that brakes are the most important part of the car. If the car doesn't start it probably won't kill you. If it doesn't STOP it damn sure can..

[bordin34]

Ok, I am going to get new bearings. Now I have another question, I am looking for rotors and all the ones I find are listed as 10.98"od I thought they are supposed to be 10.87"od. Would they 10.98" work?

[Steve P.]

I don't know for sure, but I would imagine .110 would not kill ya.. I have seen more rust build up on the outer edge of rotors than that..

Try VERY hard to find CANADIAN made rotors if you are just going with stock replacements. Much less trouble down the road..