# thump, thump, thump when braking



## haynboy8 (Apr 12, 2005)

Hello im new to the boards. I have a sentra and when i brake, i hear a thump thump thump sound coming from the left front of the car. i only hear the sound when i brake. What is the problem. Could it be hub bearings or something wrong with my brakes?


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## Slacky (May 31, 2004)

u have a automatic i suspect?


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## haynboy8 (Apr 12, 2005)

yup its an auto. Well actually its my aunty's sentra. she asked me to find the problem and fix it for her. The reason im asking on the forums is because i dont have time right now to check what is wrong because im fixing her maxima right now. so im jus going off of what she told me. so if anyone had a problem like this can you tell me what is wrong, so i can get right at it when im done with her other car??


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## Slacky (May 31, 2004)

does the rpms kick when this thumping is happening and does the car jerk at all?


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## haynboy8 (Apr 12, 2005)

the rpms do not change at all.im not to sure on the jerking back and forth, maybe jus slightly because i cant really tell. its more of a tock tock tock sound when braking. i was thinking it had something to do with the brakes, since it only happens when braking.


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## Catman (May 21, 2004)

My rotors were warped, and would make a similar noise when braking. Then, they got so bad, I did not have to brake to hear the noise. Now I have new rotors....


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## UnkalledFor (Sep 21, 2004)

thats what it sounds like to me.. warped rotors can be caused by water coming in contact with the hot rotor causing it to warp.. maybe she washed her car right after driving, and water came in contact with the rotor.. just a scenario.. in this case you have to replace the rotor


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## haynboy8 (Apr 12, 2005)

Thanks guys for the responses. I will check the rotors asap and find out the problem.


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## pete? (Jul 6, 2004)

the best way to tell is to get a straight edge and place it on the rotor, put a small flash light behind it and look for light where the edge is contacting the rotor, there shouldnt be any. some times it is very hard to tell if a rotor is warped but this sounds exactly like it is. nothing else is affected, just when you are braking.


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## Slacky (May 31, 2004)

if the sound happens faster when your slowing down from higher speeds and slwoer at a slwoer speed then i would imagine its the rotor but if its something constant reglardless of speed then idk


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## Twiz (Aug 24, 2004)

Check the rotors only if the brake pedal is pulsating when you apply the brake. If not they're not warped.


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## Hydrolock (Feb 18, 2005)

1.6pete said:


> the best way to tell is to get a straight edge and place it on the rotor, put a small flash light behind it and look for light where the edge is contacting the rotor, there shouldnt be any. some times it is very hard to tell if a rotor is warped but this sounds exactly like it is. nothing else is affected, just when you are braking.


Unless you have the right tool....


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