Rotors ?
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TrailRunnin14
New member
What rotors are you using? I’ve never had an issue with the OEM rotors on the 4Runner.
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apc9199
Member
Lets see if we can open up a whole can of worms here...
First things first, unless you're racing the 4Runner or have a 12 mile descent followed by an immediate stop-and-park situation, it is VERY unlikely that you're warping your rotors. Warping occurs when the heat within the rotor approaches the annealing temperature and is then allowed to cool quickly or non-uniformly. That temperature is in excess of 1000°F for most cast iron alloys. If your rotors were getting that hot you would DEFINITELY notice.
The more likely scenario here is what I call "stiction" between the pad and rotor at lower temperatures (but still hot temperatures). Basically, your rotors get "hot" during normal operation and the compounds in your brake pads, which are designed to create friction but keep sliding freely, "stick" to the rotor surface microscopically. That material then continues to get pounded by the brake pad every time the rotor spins under it with the brake applied creating "carbides", or really really hard spots, on the surface of the rotor. THAT is what you feel when you hit the brakes and feel a "wobble" in the vehicle. If you hit the brakes and feel the wobble in the seat but NOT in the steering wheel, the it is likely your rear rotors that are in question. If you feel it in the steering wheel immediately, it is likely your front rotors but could possibly be all four. This has been confirmed tons of times by machinists (myself included) who load their rotors into a lathe to machine the "warp" out of them only to find that they are still nearly perfectly flat when inspected with a dial-indicator. The temporary fix is the same in either case and requires machining or replacement of the rotors.
Now, what the hell do we do about this? There is not a perfectly straight forward answer to this question because it happens with nearly all rotor and brake pad types, but using high quality ceramic or semi-ceramic brake pads on high quality rotors seems to be the best bet for minimizing it. The other thing tends to be driving habits. People who brake hard and fast and don't let the rotors "slip" a little as they come to a stop experience this more often than people who roll to a stop slowly. Hard and fast results in more opportunity for those "carbides" to stick to the rotor whereas they are less likely to adhere when there is slipping occurring between the pads and rotors.
The other thing that I hesitate to recommend, but I have had good luck with, is using "Stop Squeal" (Amazon) on your brake pads. It seems to add another compound to the pads that helps to prevent sticking. For some people, adding any third party products to brake pads or rotors is taboo. This is up to you to decide for yourself. I used to have this issue all the time on smaller faster cars. It happens much less on the 4Runner, but it has still happened to me. I am still on OEM rotors and pads but I will likely switch to "Power Stop" Tow Duty pads and rotors when the time comes. I have had better luck with them than any other brake company I have ever used. Hopefully some of that proves useful to you and you're able to find a combination of parts and driving style that works for you.
First things first, unless you're racing the 4Runner or have a 12 mile descent followed by an immediate stop-and-park situation, it is VERY unlikely that you're warping your rotors. Warping occurs when the heat within the rotor approaches the annealing temperature and is then allowed to cool quickly or non-uniformly. That temperature is in excess of 1000°F for most cast iron alloys. If your rotors were getting that hot you would DEFINITELY notice.
The more likely scenario here is what I call "stiction" between the pad and rotor at lower temperatures (but still hot temperatures). Basically, your rotors get "hot" during normal operation and the compounds in your brake pads, which are designed to create friction but keep sliding freely, "stick" to the rotor surface microscopically. That material then continues to get pounded by the brake pad every time the rotor spins under it with the brake applied creating "carbides", or really really hard spots, on the surface of the rotor. THAT is what you feel when you hit the brakes and feel a "wobble" in the vehicle. If you hit the brakes and feel the wobble in the seat but NOT in the steering wheel, the it is likely your rear rotors that are in question. If you feel it in the steering wheel immediately, it is likely your front rotors but could possibly be all four. This has been confirmed tons of times by machinists (myself included) who load their rotors into a lathe to machine the "warp" out of them only to find that they are still nearly perfectly flat when inspected with a dial-indicator. The temporary fix is the same in either case and requires machining or replacement of the rotors.
Now, what the hell do we do about this? There is not a perfectly straight forward answer to this question because it happens with nearly all rotor and brake pad types, but using high quality ceramic or semi-ceramic brake pads on high quality rotors seems to be the best bet for minimizing it. The other thing tends to be driving habits. People who brake hard and fast and don't let the rotors "slip" a little as they come to a stop experience this more often than people who roll to a stop slowly. Hard and fast results in more opportunity for those "carbides" to stick to the rotor whereas they are less likely to adhere when there is slipping occurring between the pads and rotors.
The other thing that I hesitate to recommend, but I have had good luck with, is using "Stop Squeal" (Amazon) on your brake pads. It seems to add another compound to the pads that helps to prevent sticking. For some people, adding any third party products to brake pads or rotors is taboo. This is up to you to decide for yourself. I used to have this issue all the time on smaller faster cars. It happens much less on the 4Runner, but it has still happened to me. I am still on OEM rotors and pads but I will likely switch to "Power Stop" Tow Duty pads and rotors when the time comes. I have had better luck with them than any other brake company I have ever used. Hopefully some of that proves useful to you and you're able to find a combination of parts and driving style that works for you.
El Dusty
Member
My first set of rotors warped at ~70k. Very noticeable steering wheel pull /vibration to one side under mild braking. I replaced with OEM and am now at 140k with no issues. I still plan on replacing them when I do my pads very soon. Some 5th Gens seem to eat up rotors worse than others. 25 to 30k is not good for rotors though IMO. Its probably worth having a tech look them over to see if your calipers are not seized or sticky.
If and when you do replace, I would recommend all OEM parts and try to bed in the new pads and rotors early on.
Whippersnapper02
Senior Member
Are you bedding in the pads correctly?
edgesalon
New member
thanks for the info
I do drive only 20 miles each way to work and home
My first rotors only lasted 22k the local shop replaced them and the new ones lasted 30k i have no idea what they put on i will ask when i go by the shop i am just trying figure this out my last 4runner 4th gen had no issues like this
may be the shop did not bedding correctly? i thought it would be done
I do drive only 20 miles each way to work and home
My first rotors only lasted 22k the local shop replaced them and the new ones lasted 30k i have no idea what they put on i will ask when i go by the shop i am just trying figure this out my last 4runner 4th gen had no issues like this
may be the shop did not bedding correctly? i thought it would be done
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APC,
That is a great explanation. However I would replace "Stiction" with transfer of braking material. I read a very similar explanation on someone's website, StopTech, or EBC, one of those guys...
apc9199
Member
Your description is absolutely accurate. I maybe should have explained why I use that term. I can tell as soon as this problem has started by the slip-stick-slip-stick type of feeling that you get. You can feel it in the brake pedal and it makes that uneven groaning noise when braking at very low speed, like creeping along at a red light. So ym term describes the after-affect more so than the initial problem. Friction + Sticking = Stiction
Think its all been covered but check the calipers arent sticking, try OE rotors and pads and shims, clean up the hub surface, lube pins/shims according to FSM, bed in the pads, use engine breaking on long descents and flush the brake fluid every 2 years. Make sure the rears are good too.
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Too Stroked
Member
What's a "rotter?"
you have to bleed the brake fluid ..... rear fluid bleed then bleed the front brakes ...
rotate your tires inspect your brake pads ... also lube the caliper pins ...
use the silicone brake grease to lube the steel pad plates..
many owners lock up the brake pads..
the Toyota brake fluid has air bubbles in it ........
my brake pads are 40% around 70K miles .. brake pads are the same wear ..all ..
lewdog998
New member
what ever you do, ask your wife/gf or both before you start bedding strange pads without her permission.
Whippersnapper02
Senior Member
Let her watch. :heh:
I'm guessing an autocomplete mishap or some slang I'm unaware of for rusty rotors?? I mean they rust as soon as you put them in the car so kinda makes sense either way.
edgesalon
New member
sorry my bad i was making the thread on my phone
thanks for the help the shop said that the brakes are broken in at the time of test drive after the install but they did not need to be bleeded
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Jivewalker
Member
Over torqued wheel lugs or improper tightening sequence can warp/flex your rotors. Often overlooked. OEM rotors are solid quality and should last until they are to thin.
