Replacing warped front rotors


#1

I’ve got a 1993 Infiniti G20. The brake pedal has been pulsating and steer wheel vibrating when I hit the brakes. Mechanic said that the front brake rotors were warped and need to get replaced. But he said that the brake pads still had plenty of life.

I’m going to do the replacement myself, but here’s my question: do I need to replace both the rotors and pads at the same time? Is it fine for me to only change out the warped rotors?


#2

“Is it fine for me to only change out the warped rotors?”

Yes.


#3

While I suppose you could, why would you? Brake pads are cheap and its no more work to put new pads on while everything is apart. You will be assured of 100% braking performance rather than diminished performance. I can’t imagine why a paid mechanic would recommend not replacing pads too since the job would need to be done again prematurly.


#4

I would check my front tires very carefully for bulges in the tread first, I thought I had warped rotors, but it turned out to be the tire


#5

You can certainly reuse your old pads but that’s a risk a DIYer can take. The proper repair means new pads and that is the route a shop who has to stand behind their work will take.

Other than the tires mentioned by wesw this kind of problem can also be caused by a loose wheel bearing, worn suspension or steering component, etc.


#6

Those old pads have taken a set . . . what I mean is they’ve developed a wear pattern to match the grooves in those old rotors

I suggest a fresh start . . . new rotors, pads, and hardware

High quality parts will improve your chances, also. Factory parts, Wagner, Bendix, etc.

I’d stay away from store brands, for the most part. If you do get store brand, make sure they’re premium or better

As far as ceramic goes, I only recommend that if your car originally came with ceramic pads


#7

The brake system is not an area to cut corners. If the rotors are to thin to be resurfaced, replace the pads and rotors together. Use good quality parts and you will be fine.


#8

You’ll know more when you see the pads. If they are wavy, you may have too much sanding to do to flatten them out. If you have to sand much more than three strokes, you need new pads because they will be angled and I’d hate to advise you to install things that won’t work right.

If the pads have been there a while, change them without looking first. New ones can be a half inch thick on some cars. If you are getting that much shaking, your pads look bad.


#9

I would replace them both. Why have new rotors with used pads?


#10

I had warped rotors on my 2002 Sienna. My SIL installed ‘racing rotors’ to avoid future warping from overheating. Something like slotted and drilled, I think he called it. Those parts bought on-line probably cost no more than genuine Toyota rotors.


#11

Slotted/drilled rotors won’t warp any slower, and unless they’re cast with the holes in them, will crack easier than normal rotors. Unless you’re racing, you don’t need that stuff (and even if you’re racing, you don’t need crossdrilled - just slotted, and not for outgassing or rotor longevity, but to shave the pads so they don’t glaze.)

I would consider how thick the pads are, OP. If they’re not all that worn down, then why waste them? If they’re getting thin, then you might as well swap them to save yourself having to go back in and do it soon.

The old argument about pads and rotors taking a set really doesn’t hold much water. When I was younger I unknowingly did an experiment, because I was a poor college student. I got a car that was selling cheap because the brakes made lots of noise. Turns out whoever did the pads the last time put one of them in backwards. The rotor looked like a vinyl record - grooves everywhere. I turned the pad around and put it back on the car because I didn’t want to buy a new rotor if I didn’t have to, and something like a thousand miles later when I had the wheel off for another project, noticed the rotor was nice and smooth again.

Yes, rotors and pads will “take a set” to each other, but if you put new rotors on, the pads will “take a set” to them, too.


#12

Why don’t you try this first. Find an empty road and do a couple of hard stops from 60 mph. Don’t lockup the wheels but stop as hard as you can just short of lock up. Also don’t quite stop, when you are almost stopped, accelerate to 60 and repeat. After two of these, the vibration and pulsing may go away. This is a way t clean off deposits from the rotor surface and renew it.

Look at it this way, if it works, great, if it doesn’t, it hasn’t cost you much, just a little gas.


#13

@shadowfax‌

Concerning your statements about crossdrilled rotors . . .

Are you talking about aftermarket drilled rotors only?

I’ve worked on countless vehicles that came from the factory with crossdrilled rotors, and saw no cracked rotors. They usually led a normal life.

Can you elaborate, please provide some specific details. Which brand rotors, which brand vehicle, etc.


#14

For an extra $35 for a set of new pads, I would go that route.

You will be happier with the results than using the old pads.

Yosemite


#15

I’ve reused old pads on new rotors many times without a problem. Though I agree with others who say if your pads are worn, then replace them.

If it’s a customer car, then installing new pads is a worthwhile added insurance against a comeback.


#16

@db4690 Generally the ones with OEM cross-drills have rotors that were cast with the holes in them (cross-drilled is a bit of a misnomer, but it sticks). The holes don’t do much of anything useful, but at least they don’t risk cracking.

The aftermarket ones where a company takes a normal rotor and drills holes in it are the ones that are prone to issues. You don’t see those quite as much any more because the fashion has changed from fake race cars to “stanced” cars that look like they have broken ball joints. :wink: