Brake rotor problem. Strange vibration and discoloration

1990 Civic Wagon
I have been trying to diagnose a brake vibration that turns into a constant vibration within a short time.
I put brand new rotors on 2 weeks ago, and this is what it looks like now.
It only happens to the front left rotor, and so far only to the outside of it.

I replaced that rotor, greased the slide pins on the caliper, and the piston compressed as it should…
Now the new rotor is starting to look like this one already. As the rotor worsens, i also start getting vibration even when not braking.

I’ve replaced the entire front suspension (ball joints, tie rods, bushings, ect…), and just had an alignment 2 days ago. The tech that did the alignment did not find anything to be loose.

Is this a caliper issue? bent hub? axle? i’m out of ideas.
Thanks everyone!!

Has this car hit anything?

not to my knowledge.

Did you clean the rotor prior to installation?
New rotors normally come with some sort of protective coating, if it is not cleaned off it can cause problems.

If the rotors were not cleaned, new brake pads would be contaminated as well.

Yup, cleaned up good with brake cleaner before installing. always.

Both the rotor’s hub hole diameter and the wheel’s hub hole should exactly fit over the hub (i.e. no looseness known as zero clearance fit). If the hub hole diameter is to big, the wheel and/or rotor won’t maintain concentric and will cause an out of balance condition (i.e. similar to a wheel/tire out of balance).

The blue color and the vibration point to severe overheating. The fact that the inner surface is not experiencing the same problem indicates that it’s not a hydraulic problem. Your piston is retracting so it’s not binding. I think your problem lies with the caliper itself not being able to retract on the slide pins. I know said you greased them. Did the pins slide easily in the caliper?

I think you need to take another look at the the slide pin/caliper movement. Look for gunk or rust in the slide pin bores. If you see any try to clean them out and regrease them. If that doesn’t work replace the caliper.

Edit: Would just like to add that the retracting of the caliper body itself on the slide pins is what releases the outer pad.

I see a new caliper in your future.

The problem might be caused by a deteriorated rubber brake hose to that caliper.

When these hoses deteriorate, the rubber inside can come apart and act like a check valve. That is, when the brakes are applied the hydraulic pressure is applied. But when the brakes are released the hunk of rubber prevents the hydraulic pressure from releasing. Holding the pads to the rotor.

To check for this, pump the brake pedal a couple of times and then open the bleeder for that caliper. If brake fluid shoots out of the bleeder there’s still hydraulic pressure being applied to that caliper. And this is usually caused by a deteriorated brake hose.

If you find this is what’s happening, replace both brake hoses to the calipers. Because if one has failed the other isn’t far behind.


new loaded front calipers and front brake hoses

You’ve got a pad dragging.
As pretty as the blue color looks, follow db’s advice.

thanks guys. getting a new caliper this morning.

You’ll probably need a new rotor too. The vibration indicates warpage.

Still waiting for the caliper to come in. I have Russell SS brake lines i saved off my previous car so i will put those on as well

I have been down this road with a 92 Dodge Dakota.
The caliper was my problem too. Kudos to you for catching it early. I didn’t catch mine until it was way too late. The rotor was nearly worn through.

I was 17 at the time. Apparently I wasn’t very vigilant back then.

As for your rotor, I know enough about steel to say that your rotor is cooked. It is no longer as strong as it once was. Perhaps they can turn it until it looks and feels like new, but it’s more brittle than it used to be. It may crack in the future.

The first experiment I’d do w/this problem is drive the car a while, then note the temperature at all four wheels to determine if this rotor is hotter than any of the others. That would provide an important clue and is easy enough to do provided common sense safety precautions are followed.

The bottom line though, I think two new calipers, two new rotors, and two new rubber brake lines will fix whatever the problem is. New pad sets too unless the current ones were installed very recently. That’s probably the fastest and most inexpensive way to get the vehicle back on the road. When the rotors are remove do a careful visual check that the seating surface on the hub is smooth and level and not otherwise gunked up or corroded.

The only other thing I can come up with is that the rotor is being warped by over-tightening or not following the proper sequencing when replacing the lug nuts.

Edit: When installing new rotors, the recommendation is usually to clean off the surface treatment with hot soap and water. Not brake cleaner.