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12

Had some nasty brake shudder on my truck. So i turned down the bad rotors.

submitted by germ22 to Machining 6 hoursMay 10, 2025 11:43:34 ago (+12/-0)     (files.catbox.moe)

https://files.catbox.moe/ksg31r.jpg

second pic, can you guess where the brake pad sat while the truck was parked for a few weeks in the winter?
In total i took .045" of that face to clean it up completely. This is the rear rotor. I sandblasted the mounting surfaces first to get a good reading on the dial indicator setting it up in the lathe.
The rotor on the opposite side wasn't as bad and only took .015" of material removal to make it run true again.


29 comments block

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[ - ] Clubberlang -1 points 5 hoursMay 10, 2025 13:11:18 ago (+0/-1)

Dayyumm nigga pump yo brayykz!

[ - ] FacelessOne 0 points 5 hoursMay 10, 2025 13:19:20 ago (+0/-0)

@Dial_Indicator

We miss you

[ - ] peety 1 point 6 hoursMay 10, 2025 12:04:26 ago (+1/-0)

i would have tried doing a few panic stops before trying to turn it.

depending on truck use, might have been better to just buy new. thickness below minimum spec yet?

[ - ] germ22 [op] 3 points 6 hoursMay 10, 2025 12:10:49 ago (+3/-0)

If I remember correctly , minimum thickness is 1.1" for rear rotor. After machining i was still at 1.18".
I tried some hard braking, it did not work. And seeing how much material i had to machine of, i doubt it would have worked.
Buying new around here is about $200cdn per rotor. So turning them down was right now the better option.

[ - ] peety 1 point 6 hoursMay 10, 2025 12:18:35 ago (+1/-0)

i like that lathe. ones i have used have a cone and the cap that fits both sides. does that style keep the chatter down?

[ - ] germ22 [op] 0 points 4 hoursMay 10, 2025 13:40:19 ago (+0/-0)

I hat to go pretty slow and use very sharp inserts to minimize chatter. It was not a very stable setup. But sirface finish doesn't matter much for this application.

[ - ] drstrangergov 1 point 5 hoursMay 10, 2025 13:06:57 ago (+1/-0)

they usually stamp the minimum thickness on the rotor. or used to.

[ - ] Clubberlang 1 point 5 hoursMay 10, 2025 13:17:30 ago (+1/-0)

$200cdn per rotor

If you become our 51st state you can get chineesium rotors for uh hundy.

[ - ] germ22 [op] 0 points 4 hoursMay 10, 2025 13:42:43 ago (+0/-0)

I checked RockAuto, they have some for $50, but then comes shipping and plus customs brokerage fees. Lately customs brokerage fees are around $200 per package for stuff coming from the USA. (thanks Carney)

[ - ] KosherHiveKicker 1 point 3 hoursMay 10, 2025 15:04:48 ago (+1/-0)

Did it sit with a fresh coating of road salt or something? It's hard to believe that the damage was just from sitting two weeks.

Surface rust shouldn't have pitted out the rotor, or required a huge removal of materials to true it.



[ - ] germ22 [op] 1 point 2 hoursMay 10, 2025 15:41:40 ago (+1/-0)

Yes a lot of salt, and it was a bit more than two weeks. Maybe 4 or five weeks? It is rather unusual for this to happen. We had some freeze thaw cycles and blizzards in short succession. All that combined cause this issue.

[ - ] lolxd 1 point 2 hoursMay 10, 2025 16:18:41 ago (+1/-0)

Turning rotors was my first experience machining.

[ - ] drstrangergov 2 points 6 hoursMay 10, 2025 11:47:38 ago (+2/-0)*

very nice! i have a pile of rotors waiting for me to get/make a lathe. they're very useful for making stands for things. that looks like a 3/4 ton ford rotor and about 20+ years old. wise choice in vehicles. you can still get parts for it.

[ - ] bosunmoon 1 point 4 hoursMay 10, 2025 14:05:14 ago (+1/-0)

You can make a pretty rad forge out of a bigrig drum.

[ - ] big_fat_dangus 3 points 6 hoursMay 10, 2025 11:46:09 ago (+3/-0)

DID SOMEONE SAY DIAL INDICATOR???

[ - ] drstrangergov 2 points 6 hoursMay 10, 2025 11:48:11 ago (+2/-0)

dial indicators were dial indicators before dial indicator.

[ - ] Peleg 1 point 6 hoursMay 10, 2025 12:30:29 ago (+1/-0)

Yeah, but, dial gay!!!!!!!

[ - ] drstrangergov 1 point 5 hoursMay 10, 2025 12:57:43 ago (+1/-0)

dial happy.

[ - ] lolxd 0 points 2 hoursMay 10, 2025 16:15:10 ago (+0/-0)

Dial Gay.

[ - ] observation1 3 points 6 hoursMay 10, 2025 11:59:52 ago (+3/-0)

Fabulous.

The fucking shops, around me anyway, won't do this anymore. They just make you buy new ones.

[ - ] germ22 [op] 3 points 6 hoursMay 10, 2025 12:13:23 ago (+3/-0)

Depending where you are it might be cheaper to buy new ones compared to the cost per hour to machine them. Doing it on a lathe is not cost effective if you hire a machine shop. If you have a brake lathe it might be feasible, but still it's rare for mechanic shops to even have one of those brake lathes, let alone use them.

[ - ] observation1 2 points 6 hoursMay 10, 2025 12:22:24 ago (+2/-0)

And they have audacity to call themselves break shops

[ - ] Clubberlang 0 points 5 hoursMay 10, 2025 13:13:02 ago (+1/-1)

Dass wuh yoo tayke duh whip wennit bee broek nigga dayyumm!

[ - ] Peleg 1 point 6 hoursMay 10, 2025 12:28:23 ago (+1/-0)

LOL
You must be in a nigger infested area. Every shop in my county has a brake lathe. Even a lot of the back yard mechanic shops have them. The last time I had my rotors resurfaced I believe they charged me something like $20.
The problem is that they Always tell you that they can't be done because they are already too thin. Bunch of lying bastards. Always trying to rip everyone off.

[ - ] drstrangergov 1 point 5 hoursMay 10, 2025 13:05:25 ago (+1/-0)

isnt that something? brake lathes are small and simple. they used to have them at many parts stores. i suspect things like osha got rid of them because muh safety. all part of the deconstruction of american self sufficiency i suspect

[ - ] Clubberlang 0 points 5 hoursMay 10, 2025 13:14:38 ago (+0/-0)

Independence? I think I saw that on a piece of paper one time before we got rid of it for faster internet speed.

[ - ] mikenigger 2 points 3 hoursMay 10, 2025 15:01:59 ago (+2/-0)

newer cars don't have enough extra material to do this anymore

[ - ] lolxd 0 points 2 hoursMay 10, 2025 16:23:13 ago (+0/-0)*

I think my employer bills $180-280 an hour for hand machining stuff like this, rotors manufactured these days are cheap because they make like 100,000 of them in a robot cell staffed by 3 people in a month. It's frankly cheaper to buy a whole new set.

[ - ] observation1 0 points 1 hourMay 10, 2025 17:20:15 ago (+0/-0)

Not my rotors. Even rockauto is a fortune.

And mine can be turned.