Are my driving habits creating hot spots on my rotors?

In March of this year I had front brakes & rotors changed on my Ford Ranger (1995 V6 2.3L manual transmission). About nine months later, I began noticing vibration when braking, especially at highway speeds. (Certainly could have been coming on sooner, but I did not notice.) The mechanic said there were “hot spots” on the rotors so he rotated them & charged me. From talking to other folks, I agree that the rotors were the most likely cause. BUT the mechanic insists that I need to change my driving habits (implying that I caused the problem) by downshifting to slow down & thereby sparing the brakes. I have been driving this truck for 15 years & have never had this problem. I do brake when I need to slow down - I assume that is what brakes are for! I asked if there is any other reason the rotors could have a problem including defective parts, improper installation, etc. & the mechanic insisted that he never has this problem. In the end I did pay but demanded that if this problem recurred I would not pay again & he agreed. THanks for any advise, Monica

Rotors are made from scrap, many imported from China, the cast iron, if you can call it that, is often full of inclusions (unknown material), your “hot spots” reflect the junk from which they were made… At least, with factory rotors, there is SOME quality control…With aftermarket brake parts, it’s a crap shoot… Some are serviceable, some are worse than the old rotors you threw away…

Some rotors are poorly made and likely that is what caused the problem. I seems most of them come from China. I make sure my rotors do not come from China. Maybe in 30 years China will have their act together and will get the junk out.

40 years ago Japan had the same problems. They addressed the issue and today they produce some of the best cameras available. Cameras were one of their first efforts.

Everybody blames the rotors, but it might be the new compounds in the pads. It seems to be worse with new pads and gets better as they wear/age. Your mechanic is 100% wrong. You need to be harder on your brakes so you burn off the deposits that cause the pulsing/shudder.

Every time I’ve changed pads lately, new rotors or not, I’ve had this problem which I solve with a couple of hard 60-5 mph almost stops. I don’t come to a complete stop as I don’t want the rotors to get too hot under the pads. After a while, they stop doing that.

I don’t think your mechanic’s right, you don’t need to ‘spare’ the brakes. Besides a rotor, or maybe pads, another cause for this is improper torque on the lug nuts, warping the rotor. And that’s up to the mechanic.

Thanks so much, will find out where rotors came from… Monica

Thanks so much, will find out where the rotors came from… Monica

Wow opposite advice from the mechanic who said to be gentle with the brakes for a while, I’ll share your experience with him. THanks, Monica

Thanks for another possibility, I’ll share with the mechanic, Monica

Is your truck a V6 or a 2.3 liter? I don’t think it could be both!! I can’t tell from your post if the mechanic said you should downshift to save the brakes or did he say that you were downshifting and that you should not, therefore causing the problem.

Oops sorry misspoke - it is a V6 4.0L. And yes I wasn’t very clear in that sentence. The mechanic said I should downshift to slow the car and thereby save or spare the brakes. He implied that because I use the brakes and do not downshift to slow down that I am contributing to the problem. Thanks for your careful reading, Monica

If you are driving in the mountains and are not using the gears to slow the car on descending steep hills you can overheat the pads and rotors causing warped rotors.You can even get the fluid hot enough to boil which is when you will find out how useful those runaway truck ramps filled with deep gravel are.

Thanks for the experience, I do down shift to control speed in mountain driving, but this truck is our secondary vehicle & we typically just drive it within an hour or so of our home 99% level streets & highways. I think the biggest hill I drive it on is probably only 500 ft & not very steep.

Absolutely a rotor composition/pad composition situation. You do not need to develope a downshifting habit. The idea of “bedding” the brakes does have merit in regards to eliminating a pulsation situation,it is not always sucessful

There is another view to be considered. When braking hard to a stop, the generated heat at the point where the pad is clamped to the rotor at standstill dissipates slower than the rest of the rotor. Do you feel this is significant enough to cause ?spot-warping?. One solution I have heard is to allow the tire to creep after a hard stop to prevent the pads to remain in the same spot to avoid heat soak. I have not seen any data to support this, but just food for thought.