Brake Rotors

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rjdelp7

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I bought a used Lincoln, that sat on a gravel driveway. It was parked for weeks and the front rotors had some surface rust. The area behind the pads stayed clean. Driving/braking, cleaned off the rust and a slight pulsing developed. It had nothing to do with heat. They are not 'warped', they are just worn ruff. I was told 'better' rotors have more carbon in the steel and don't rust as easy. No one 'turns' anymore because the thin rotors warp. You have to drive like some kind of *******, to get brakes hot enough to warp. Even towing, your trailer brakes should be doing there part and not heat up the trucks. Certain wheel designs, expose the rotors weather. My 2000's has smaller wheel openings and never had a problem.
 
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Plati

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The rotors being sold today are made using lower grade steal (not a strong and less resistance to bending) and are much thinner.
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I know brake rotors can be made from various materials but aren't most of the standard ones made of cast iron? The better ones are high carbon cast iron (with various other metals in the alloy) .. And don't rust too bad either. Steel would be unusual.

I think pushed hard brake rotors can get up to 400 degrees F and the melting point of cast iron is over 2100 F.
 
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MrSticker said:
I know brake rotors can be made from various materials but aren't most of the standard ones made of cast iron? The better ones are high carbon cast iron (with various other metals in the alloy) .. And don't rust too bad either. Steel would be unusual.

I think pushed hard brake rotors can get up to 400 degrees F and the melting point of cast iron is over 2100
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There are some made by cast iron or cast steel. The best are made from machining high grade carbon steel, but those are extremely expensive.

In our area several of the Auto parts stores still turn rotors and turn a pretty good number of rotors per year.

Having a pulsating brake pedal does not mean the rotor is warped.
Easiest way to determine if a rotor is warped is to jack the car up, remove the wheel, put a dial indicator on the rotor, rotate the rotor and check the run out.
 

Plati

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I'm not a metallurgist ... But I'm trying to teach myself as much as I can about that subject. Steel starts to get soft in the 500 F range. I really think the kind of rotors we buy for our Expys are cast iron. I could be wrong. Glad to admit it if I am because I want the right answer and I want to learn.
 

TobyU

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I don't worry about it. I don't care what they're made out of. It does seem to be closer to cast iron to steel but I don't think it's the same type of cast iron as an exhaust manifold or other cast iron. I'm sure there's percentages and all that kind of stuff with Alloys and such. I just compared rotors to rotors, price to price, and what works.
 

Plati

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I don't worry about it either. I don't worry about anything anymore except my parents health and well being. I'm too old to worry, figure I'm lucky I made it past 40 ... Didn't think that would happen.

I do however try to understand the quality of the parts I put on my Expy since I drive it on long trips in all kinds of terrain and conditions. I hope to drive the Alaska Highway in the next couple years. I had scrappy rotors last summer in the Rockies all rusted and pulsing going down mountains. Try driving MtWashington, the Beartooth Highway or the Going to the Sun Road sometime and youll put a little extra effort into making sure your braking system is up to *****. You might even spend an extra $75 on the chance that the parts are better.
 
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Scott B

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Brake Stop rotors (cross drilled) and Brake Stop pads for my 2000 and 2015 work great.
 

Steve Owens

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I went with the new Wagner rotors and Wagner OEx pads. Drive in the mountains, pull a Bass Boat, and they have awesome stopping power, no warping or fade after 22K. Hardly any dust on my wheels.
 

joethefordguy

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Here's what I've found on taking care of any rotors if you care.
Avoid getting them wet when hot. That can warp them quickly.

After braking especially hard but even at stop lights if they are hot....don't sit with foot on brake in one place on rotor.
Either shift to park and let foot off brake pedal or let it roll 6 inches every few seconds.

TobyU
this didn't happen on a Ford, but it is related. a 1988 Honda Accord, racing down a steep, curvy hillside road; so a lot of braking and turning. had to stop at a gate post at the bottom, on a slight slope, so i sat there for a minute talking to the guard with my foot on the brake. she noticed my fronts were smoking, so I pulled up the parking brake and got out. the rotors were too hot to hold my hand near them. we were in the middle of the woods, so I just stood there waiting to see what else might happen. the smoking stopped, i checked, they had definitely cooled. when i tried to drive off, the front wheels were frozen in place. it took about 15 minutes for the wheels to cool down enough to release. never did that again!
 

bobmbx

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Here's what I've found on taking care of any rotors if you care.
Avoid getting them wet when hot. That can warp them quickly.

After braking especially hard but even at stop lights if they are hot....don't sit with foot on brake in one place on rotor.
Either shift to park and let foot off brake pedal or let it roll 6 inches every few seconds.
What do you do if it starts raining?
 

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