pulsing feeling in brakes and dragging brake - solved

mcurcio1989 · #1 03-16-2016, 10:15 PM

Just a quick fyi, something to keep an eye out for. I was out of town for a week, home for a weekend, and then out for a week. When I got back in my car and hopped on the highway I felt what I thought was my out of balance tires but seeming worse than before (must have just gotten used to that). Nope it was definitely worse and making a rumbling sound now.

I got out check things and noticed nothing, rumbling actually seemed to go away but vibration was still there. Next day it did it again and this time I found that my front left wheel / brake were very hot. Then I noticed it grabbing quite a bit at stop lights. I took the caliper off thinking maybe the pads were binding on the caliper. I noticed the boot around the piston was torn. When I tried to compress the piston back in to make some room to slide it back it did not want to move. I didn't take it apart but I'm certain that the boot tore and the piston began to rust. Probably some time ago. After I replaced the caliper the vehicle is driving way smoother and with way more power. I also notice much less brake force. I think It just slowly crept up on me to where I didn't notice the problem until the car set a couple weeks and the rust got worse. I don't even know if my tires are actually out of balance it may have just been this. The weird thing is the brakes don't pulse now but when they got really warm they were. I don't get that.

Word to the wise - When you have your wheel off check these boots. AZ stocks a brake rebuild kit for 7 bucks a side that give you the piston seal and boot. In the future I will replace the boot if I see one torn.

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jopecasa · #2 03-17-2016, 04:07 AM

Glad you fixed your issue.

ABS and DSC errors should have displayed on the cluster....really does not matter now!

upallnight · #3 03-17-2016, 09:47 AM

Quote:

Originally Posted by mcurcio1989

Just a quick fyi, something to keep an eye out for. I was out of town for a week, home for a weekend, and then out for a week. When I got back in my car and hopped on the highway I felt what I thought was my out of balance tires but seeming worse than before (must have just gotten used to that). Nope it was definitely worse and making a rumbling sound now.

I got out check things and noticed nothing, rumbling actually seemed to go away but vibration was still there. Next day it did it again and this time I found that my front left wheel / brake were very hot. Then I noticed it grabbing quite a bit at stop lights. I took the caliper off thinking maybe the pads were binding on the caliper. I noticed the boot around the piston was torn. When I tried to compress the piston back in to make some room to slide it back it did not want to move. I didn't take it apart but I'm certain that the boot tore and the piston began to rust. Probably some time ago. After I replaced the caliper the vehicle is driving way smoother and with way more power. I also notice much less brake force. I think It just slowly crept up on me to where I didn't notice the problem until the car set a couple weeks and the rust got worse. I don't even know if my tires are actually out of balance it may have just been this. The weird thing is the brakes don't pulse now but when they got really warm they were. I don't get that.

Word to the wise - When you have your wheel off check these boots. AZ stocks a brake rebuild kit for 7 bucks a side that give you the piston seal and boot. In the future I will replace the boot if I see one torn.

Extreme heat will cause the rotor to warp. Probably a good idea to replace the rotor at the same time you replace the caliper and pads.

mcurcio1989 · #4 03-17-2016, 10:28 AM

^Well that's what I'm saying is odd. When it was dragging the more it heated up and dragged the more it would feel like the rotor was warped a little bit. However, once the rotor cooled this would go away With the new caliper on there is no indication whatsoever that the rotor is warped. My understanding has always been that extreme heat permanently warps rotors. It may have been an issue with deposits or something I don't know. All I know is my braking is smooth and responsive now. There is no way I'm replacing this rotor now. In my experience metallurgy seems to play the biggest factor in brakes warping. Rotors never have warranties the way brake pads do which makes no sense other than that the manufacturer doesn't want to deal with tons of rotors getting returned from pulsing / warping (either from over heating or deposits) or they don't want to take responsibility for warping from a bad mix and or pour at the foundry. I also didn't replace the pads because they have 95% life left.

upallnight · #5 03-17-2016, 12:25 PM

Quote:

Originally Posted by mcurcio1989

^Well that's what I'm saying is odd. When it was dragging the more it heated up and dragged the more it would feel like the rotor was warped a little bit. However, once the rotor cooled this would go away With the new caliper on there is no indication whatsoever that the rotor is warped. My understanding has always been that extreme heat permanently warps rotors. It may have been an issue with deposits or something I don't know. All I know is my braking is smooth and responsive now. There is no way I'm replacing this rotor now. In my experience metallurgy seems to play the biggest factor in brakes warping. Rotors never have warranties the way brake pads do which makes no sense other than that the manufacturer doesn't want to deal with tons of rotors getting returned from pulsing / warping (either from over heating or deposits) or they don't want to take responsibility for warping from a bad mix and or pour at the foundry. I also didn't replace the pads because they have 95% life left.

That's because the new caliper is not sticking like the old caliper, so the brakes are not always on, so the rotor is not overheating. Pads sometime become glazed when they are overheated. Since you didn't post any pictures on the condition of the pads, my reply was just base just on what you posted. Your money, your life.

mcurcio1989 · #6 03-17-2016, 01:07 PM

Yes, so my question is are you saying that the rotor is warping when it is over heated and then perfectly fine under normal driving conditions?

In the past when I have had rotors warped any time you pressed the brake you could feel pulsing both in the pedal and in the entire vehicle.

As I said my brakes operate perfectly fine now. With that being the case, I don't understand what the problem is with running rotors and pads that operate perfectly fun under normal driving conditions but may pulse if they are operated outside of there design?

I also don't get why you are implying that my life is at risk? What do you see happening here? My brakes are performing perfectly fine. Are you saying that some kind of total failure is going to occur? Or would it just be that the "warped" rotor gets further warped and has a constant pulsing anytime the brake is pressed? At which point I would obviously replace it.

upallnight · #7 03-17-2016, 01:35 PM

Brakes are probably the most important system on the car. If you can't stop a two and 1/2 ton vehicle than you are putting you life as well as the life of other people in danger.

If your system has been compromised because of the rusted caliper it may fail when you really need it. Did you inspect the rotor with a dial indicator to see the run out? Did you inspect the pads to see if they were glazed?

If it was my X, I would just replace the rotor and pads while I was replacing the caliper. Hopefully when you installed the new caliper enough of the old brake fluid was removed during the caliper exchange. But that just me. I rather be safe and not sorry with my family in the car.

Here's an article on why brake fail.

http://www3.ambest.com/DPSDirectoryS...ashx?mmid=7118

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