I have a 2002 Toyota Sequoia and it's going to kill us.Over the past year we've run into this ongoing problem...While driving, the Trac off/VSC light comes on -- no big deal.But at the same time the Sequoia shutters violently and pulls to the right as if brakes locked. It only lasts for a few seconds, but it's truly a frightening experience.There is no particular time or reason for it to happen. It could happen on the freeway, on a side street, on the straight away or going around the curve, going fast or slow.Now here's the thing, it doesn't happen consistently. We can go a month or two without it occurring. And then it'll happen every day for a week, every time we drive it.We have a great mechanic (I think), we've been with him for years.He contacted Toyota and they sent him some sort of "advisory" stating that the rear axle can leak and that it will cause the bearings to rust -- which could be the cause. But no recall was issued.Anyway, he pulled out the rear axle and sure enough it was leaking and the bearings were rusted.He replaced the rear axle (all other axles were fine). He also replaced the sensors.And for a few months everything was fine -- then it started in again.He found then that rotors were terribly warped. He rounded them.For a few months everything was fine -- then it started in again.We balanced and rotated the tires, we prayed to the Toyota gods -- no effect.We can go for weeks with everything fine -- and then for weeks, it'll happen every day, or every other day or once a week.My mechanic says he's out of ideas.Help, please.Thanks.
Hello and thank you for choosing just answer,
I have a few things that I'd like your mechanic to try and inspect but first I have a question for you and I need an accurate answer to determine the problem area.
When the problem happens are you sure that the vehicle pulls to the right? or to the left or both?
I have dealt with a similar problem actually today at my work(I work at a Toyota dealership). What happens is the calipers locking up randomly and failing to return to their "not applied" position, The reason for this is rust. The brake caliper is what houses the pistons that extend to push the pads against the rotor to stop the vehicle, Then there's a seal in the piston that actually returns the piston to the not applied position, If rust builds up around the piston it will cause the piston to bind and not return to it's not-applied position and cause the pad to stay applied and cause the rotor to overheat. When the rotor overheats the first symptom is the warpage, then it will develop hot spots which are extremely hard spots that will be higher than the rest of the rotor, when the rotor heats up to a certain temperature these heat spots will be apparent and everytime they pass by the pad they will cause the vehicle to basically brake and nose dive. It's a scary feeling that I totally understand as I have experienced it as well.
I asked you which side the vehicle pulls when it happens to be able to determine which side is causing the problem. Also I need your mechanic to take out the front pads and measure them accurately, I need to know the pad thickness in millimeters on the front pads, I need him to measure each pad from 4 corners and give me all the readings so I can be able to tell what's going on accurately.
I am assuming all the above based on the information you provided, I understand that you are frustrated with the problem and I totally understand the hazardous nature of this problem but I will do everything that I can in this format to be able to find a solution with your mechanics help since I don't have the vehicle in front of me.
Let me know which side the vehicle pulls to when it happens and the measurements of all front pads, Remember I need accurate measurements and not estimations and 4 measurements of each of the 4 pads and also what is the location of the pad.
Thanks for getting back to me so quickly. Whenever I drive it, it pulls to the right. When my wife gets home, (she refuses to drive the Sequoia now -- she's riding the bike to the store -- seriously) I'll ask her if she noticed it pulling only to the right.
Hello Barry and Thank you for your response.
I am so sorry to hear about the issue that you have with your Sequoia. I hope with my help you will be able to fix the problem and enjoy driving your vehicle safely without issues.
Let me what the measurements that your mechanic finds and I'll do my best to help. If your vehicle pulls to the right without the brake pedal being applied then the problem area is most likely the right side which is the passenger front brakes. However a comprehensive inspection of the pads and their pattern will tell the exact problem area. I think your problem is in the front brakes and not the rear. I would like your mechanic to also describe the condition of the rotors and the thickness of the rotors as well. What I would like him to note about the rotors is the color, Does he see any blue spots on the rotor? Also when he takes the pads to measure them try to push each one of the 4 pistons and see if any of them is binding or hard to press in.
Let me know what he finds.
I am available here everyday in the morning until 10:30AM central time then I will be back at 9:30PM central time, I am here all day Sunday and Monday.
Hi I spoke to my mechanic, he said he checked the calipers the last time -- when he rounded the rotor -- and they were fine. But he'll check it again, nonetheless.
OK additional to what I asked from your mechanic have him check for codes for the VSC and TRAC. See if he sees any codes.
He's always been checking for codes and nothing ever comes back.
I don't think air in the hydraulic system will cause this problem.
I don't usually like replacing expensive parts based on frustration and desperation so I will not endorse nor recommend replacing the ABS module since I don't see a reason to.
I will opt out of the question and let other experts share their view on this problem so you can get more than one input.
Relist: Other.He didn't have an answer
Hello. I see that you have relisted your request. Please allow me to add some input for you to relay to your mechanic.
We have observed this issue in our shop a few times. We observed no codes present in the computer.
What we found was a cracked ABS counter gear. This device is basicly a toothed gear, that the ABS sensor uses to 'count' wheel RPM. If this gear is cracked, rusted, damaged, teeth are missing, anything less that perfect shape, the ABS sensor sees the issue, and reports this issue as a zero RPM signal to the ABS computer, which will activate the ABS ,and cause the pulling.
This is what needs to be done:
Disassemble the front and rear hubs to the point where the ABS counter gears can be closely observed. Look for cracks, rust between the teeth, missing teeth, rust particle buildup in the hub/sensor area, things like that. A close visual examination is more than likely going to show your mechanic exactly what is wrong.
The ABS rarely activates on its own, it relies on the sensors to instruct it to activate, and what to do when activated. The sensor wheel condition will cause the ABS to active prematurely and irregularly.
Thanks for choosing Just Answer. I am sure that this information will be very beneficial to you and your mechanic.
Have a great day.
Thanks for chiming in. I relayed the info to my mechanic. He thought that might be a good idea. So he's going to check it out.
You are very welcome.
My colleague AMD and I hope you are now able to get the situation sorted out.
Looking forward to hearing from you with positive news.
Well, no luck on the gears. He said there's not even a scratch on them.
I would be concerned about anybody fashioning field expedient shims for your steering rack if I were you. In my shop, I have a very firm policy about not modifying the factory design, and especially if the part is worn in significant fashion.I would doubt that "turning the rotors" has anything to do with this, unless one rotor is markedly different in thickness. If this is so, the brakes, when applied, are not stopping the vehicle evenly. This will indeed cause a RPM difference, which will be read by properly functioning wheel speed sensors.If I were you, my next step would be to have the vehicle road tested with a scan tool hooked up, with the ability to read the RPM sensors on the screen. I still believe that the RPM sensors are causing your issue. The ABS is not designed to activate indiscriminately. There is an issue that is activating the ABS, in my opinion. A road test, with the RPM of all 4 wheels being compared whilst driving, and under all braking conditions might tell more of the cause.
Well we can scratch the shim theory anyway. Apparently it was removed by the tire place last week when they balanced and aligned the wheels (thinking that might be the issue). But this shuttering started before we took it in.
You have a good weekend too. Hoping you get it sorted out soon.
The real annoying thing is that it doesn't happen with any pattern. It might not happen again for a week or month. All we know for sure is that it shutters and pulls to the right.
Quick question: What does the refusal of the Trac off to stay off indicate -- could that be the clue to this damn mystery? No more than a minute or two after turning it off the light disappears on the dashboard.