Testing if a Rotor is Warped - No Dial Indicator!

Mike shows how to test for warpage of rotors using unconventional techniques, without fancy dial indicators or expensive tools. Spoiler: Mike's rotors are warped! He also shows how to replace them.
BONUS: Mike crashes into his house!
#rotors #warped #warpedrotors #mikethebackyardmechanic

[@rickconstant6106]

I'm a retired mechanic, and I would always clean the rust off the face of the hub before installing a new disc (rotor), to ensure that the new one would sit flush against the hub. I would also always fit new pads when fitting new discs to ensure even wear during the bedding in process.

[@MikeTheBackyardMechanic]

Good tips!

[@karldumeury9775]

Not cleaning the hub may cause the new rotor not spin perfectly in a y-axis

[@BenEyah]

I don’t think you need to use the impact to put the disc retainer screws on, just nipped up would be fine. I’d say they’re far over torqued from spec

[@evb-sy8rk]

I like the way you explain what’s happening good video 👍✌️

[@faresnar09]

Very smart idea to test the rotors with simple tool, unfortunately one time before, I forgot to restore the brake because someone was annoying while working, sadly many things happened.

[@oldtimefarmboy617]

Put never seize on the threads of those hold down screws and they will not be so hard to remove. Also, you only have to tighten them just enough so they do not back out. Their only purpose is to hold the rotor in place while the brake caliper and pads are being put on or when changing a flat tire. When you put the wheel on and tighten down the lug nuts the rim is what will keep the rotor securely in place, not the screws.

[@MikeTheBackyardMechanic]

The anti-seize is a good tip. I can't in good conscience leave them off due to the possibility that they are centering the rotor more than the lug bolts are.

[@ashleyrosevear4319]

Don't torque one screw up without the other when fitting new rotors. Same as tightening wheel nuts. Or a cylinder head...

[@SportsMusicCars]

I get a bit of a shake on the highway if I press the brakes hard and replaced the rotors about 2 yrs ago as the shake was MASSIVE then. 1 yr ago I replaced a stuck caliper, so possibly the rotor(s) are a bit out of thickness variation. Taking them to O'Reilly tomorrow to have them measure and if necessary cut them to be even. Never been cut so should have enough thickness to still be safe.

[@benjones9060]

Good info!!!!

[@alanwilson7417]

Thank you for your video. I have a 04 Lexus rx330. It had exact problem you described. I turned rotors, brake pulsing and steering wheel shimmy gone.

[@MikeTheBackyardMechanic]

Glad it helped! I have a video for changing brakes on a Lexus is250 coming up soon.

[@tamikingsley8140]

Hi, can you have a warped rotor but only have occasional indicators? My breaks will occasionally feel like they are pulsating, I guess is what you could call it but it's very random. Also had mechanic look at it and said everything looks fine. Had tire shop do brake check and got the all clear. We have replaced the 2 anti lock brake sensors but still happening

[@andrewwmacfadyen6958]

In most cases of brake vibration vespecially with vented discs the disc isn't warped the issue is caused by friction material backed into the surface of the disc, fitting new quality brake pads which have an abrasive break-in layer usually fixes the issue. Rake vibrations were a major issue on 1970:s era European Fords with strut suspension particularly the Capri and abrasive coated pads were all that were required to cure the problem

[@MikeTheBackyardMechanic]

I like that tip!

[@TheAriiiiii]

Thanks for video

[@jeffkeryk3550]

You might be screwing yourself up by tightening those rotor screws... And those pads looked pretty shot! I like the c-clamp to keep the pads from spreading

[@MikeTheBackyardMechanic]

I have tightened and retightened those screws many times. It's fine. And yes, I should have changed the pads with the rotor, you are right!

[@jamesrichardson771]

hey hey Hey' 💥 You didn't grease the slider pins! 😵 you'll be sorry 🎶💸

[@MikeTheBackyardMechanic]

This video was fairly sloppy. I've tried to tighten it up since then.

[@robdixson196]

The car got a new half shaft very recently too. :)

[@ffsdeltax]

can warped rotors cause a steering wheel wobble at highway speeds? i get this bad steering wheel wobble and rims and tires are balanced, all zeroed out.. cant figure out why i got this steering wobble. tried everything.

[@MikeTheBackyardMechanic]

Not likely, without putting on the brake. First thing to try is to retorque your wheels in a proper star pattern. I had a shimmy with my new rims until I did this. If that doesn't do it you need to take things apart and make sure things are clean and mounted flush and correctly (rotor, wheel, hub face).

[@dr.detroit1514]

Great video. Is it necessary to check for warpage on new rotors? I'm about to replace the rotors and pads on my car at this time.

[@AlexOsbaldo]

All rotors will have some warpage each car has its own spec

[@briandimascio3624]

I just did mine & crashed into my house for good measure. All good now 👍 thank you! 😜

[@MikeTheBackyardMechanic]

HAHAHA! You "should have" watched my video until the end🤣

[@marksancken9571]

its not that rotor is warped . its the thickness variation that make the brakes shake. that is caused by wear from run out like you showed. so when the new rotor is installed run out needs to be checked under .002 or less or in about 10,000 miles it will shake again . not warped just worn uneven from run out. a on car brake lathe is the best repair if the rotors are thick enough.

[@MikeTheBackyardMechanic]

Probably true. I plan to do a follow up video on rotors, addressing this issue.

[@SportsMusicCars]

Agreed. I get a bit of a shake on the highway if I press the brakes hard and replaced the rotors about 2 yrs ago as the shake was MASSIVE then. 1 yr ago I replaced a stuck caliper, so possibly the rotor(s) are a bit out of thickness variation. Taking them to O'Reilly tomorrow to have them measure and if necessary cut them to be even. Never been cut so should have enough thickness to still be safe.

[@drkgumby]

Why not test the new rotor to ensure that is is not warped,? Would also show us what a consistent measurement should be.

[@benjones9060]

Troll

[@MikeTheBackyardMechanic]

That's absolutely right, and I was planning on doing that. But then it was dinner time.

[@carlwhoha769]

Why didn't he ever use a torque wrench?...

[@MikeTheBackyardMechanic]

Certain screws I just know the feel - large ones are 100, small ones around 35... but I use the torque wrench in my videos now, or at least state the spec.

[@reynaldopaguio3059]

He did not use a torque wrench when tightening the lug nuts. Pretty sure they are over torqued.

[@charlesking9297]

Not sure where the pencil came into play you used a red gizmo, no pencil. Also you dont impact lugs on unless you use torque bars which you didn't. Lastky those little screws do not need to be hammered on just lightly snug with a phillips, those are just to hold the rotors steady , many mechanics dont even pit them back on

[@richardb7093]

Had my tires rotated and had the opportunity to see the tire being fastened to rotor. The mechanic did Not use the correct sequencing. Instead fastened as he went around the rotor. This wrong procedure is one cause for warped rotors especially when hot rotors meet water on the road. Yes it was at the dealership.

[@MikeTheBackyardMechanic]

Yeah... and that hub needs to be cleaned - and it's unlikely ANYONE does that. No excuse not to use the right torque pattern though.

[@AP-hz8or]

leave those dang screws off only there for factory assembly

[@hamburglarbooger9173]

I had no problem removing those rotor screws Just need to use the proper size screwdriver, Also I think you are way over tightening them on re install They only need to be snugged and flush

[@MikeTheBackyardMechanic]

I might be over tightening them - but I initially could not remove them without the impact driver.

[@paulsteenhoff9357]

Clean the wheelhub and then put Some coppergrease on it. So it Will losen up easily next time

[@MikeTheBackyardMechanic]

Good tip. I have been doing that since.

[@joshkrause2977]

Rotors are so cheap I just replace them with the pads, checking to see if the hub is warped is more important.

[@MikeTheBackyardMechanic]

Yes, replacing them with the pads is a good idea. The rotors for the Pilot are $130 bucks from the store although I have found them significantly cheaper online. I'm still doing research to determine rotor quality.

[@rickconstant6106]

Another point - although it wasn't mentioned here, you should never replace just one disc (rotor), always change both sides, or you will have a braking imbalance.

[@MikeTheBackyardMechanic]

Such an obvious point I didn't think to make it. Thanks!

[@dalemihocik4732]

I always believed that you needed to replace rotors in pairs until the owner of an automotive machine shop told we otherwise. He said the measurement of a new rotor and used one is so close it doesn't matter, just as long as you replace both sets of pads. I've recently done this without any issues.

[@rickconstant6106]

@@dalemihocik4732 It's not so much the thickness of the disc, it's the condition of the surface that makes the difference. If you have a brand new disc with a completely flat surface, it is going to give a different braking efficiency from a part worn one with even light scoring. This could be critical on front brakes, where balance across the axle is essential.

[@dalemihocik4732]

@@rickconstant6106 Your correct about the surface condition of the disc, I failed to mention that the rotor would have to be in out of the box condition minus a few thousandths of wear.

[@A.C.71]

Guess I'm confused, you mention using a pencil the next thing I see is the plastic guage.

[@MikeTheBackyardMechanic]

I have an upcoming video where I use an actual indicator! That will clear up the confusion.

[@scottcates]

Why not

[@MikeTheBackyardMechanic]

Well... I didn't have one.

[@mikethompson3534]

If this was a Japanese car those screws on the rotors are not Phillip screws but JIS screws and that is why those screws get messed up You need a #3 JIS screw driver to remove them or the next time the same thing will happen again

[@kacperzalecki969]

VW spec is 8Nm for this little screws. Definitely you should check specs for yours car, clean hub's and don't rebuild neu rotors witch old break pads 😮

[@MikeTheBackyardMechanic]

All true. I try to do things more by the book these days.

[@jerrygunn5873]

New roter old pads, huh?

[@MikeTheBackyardMechanic]

The real sorry thing is, I had an extra set of pads that I forgot to use!

[@holycow3355]

1/1000 of an inch, wrapped 10/1000 of an inch, couple of human hair thickness, really make much difference in braking efficiency, just wondering ?!

[@MikeTheBackyardMechanic]

4/1000 or 0.004 of an inch is spec. You won't feel much at 0.010, but you will start to feel it at 0.030.

[@benjones9060]

Third... 🥺

[@tonyman2c]

I think it's too difficult to have the rotor perfectly vertical to test this way.

[@MikeTheBackyardMechanic]

Verticality does not affect the runout that I was testing. If the rotor was tilted 45 degrees, it would still spin the same.

[@scottocken1209]

Always check the hub for runout, easy to do and only takes a few minutes and clean the hub! Always torque the wheel lug nuts as per proper procedure. This is not a good video, much misinformation.

[@MikeTheBackyardMechanic]

I plan to do a follow up video soon to not only correct mistakes but provide more (better) information.

[@Twinturbo_]

Rotors don't warp

[@MikeTheBackyardMechanic]

Nah - no way! Watch my later video.

[@Twinturbo_]

@@MikeTheBackyardMechanic it's the deposits of the brakepads. I thought that my new discs were warped. After slamming the brakes for a period, the shaking is gone.

[@badgerm3837]

There is no such thing as a "warped" rotor, it's uneven glazing. Rotors could sustain heat to the point of glowing hot and still wouldn't warp.

[@MikeTheBackyardMechanic]

I understand. And these rotors are "warped" again (less than a year later), so I am going to do a better breakdown of what is happening.