Braking 有怪聲，求助

kencyliu

先自我介紹
年份2000
Subaru Impreza 2.5RS
mileage 剛過200K
最近換了呔，磨了front rotors及換了front pads, 一直都好好，但兩星期後開始braking 有聲，是低音的格格、呱呱聲。
40kph以上冇，凍車又冇，但開了二十分鐘左右開始出現，只是輕輕braking才有，大力些又冇，聲音頗大，來自車底，分不清左或右，頻率隨車速改变，除了有怪聲外一切正常，冇震，煞車効能好好。
返車房檢查一切正常。
在其他forum都找到相同的問題，但都是沒有確實的解决方法。
希望有達人能指點一二，謝謝。

Lik

一般來講，踩 brake 會唧唧聲都係常有嘅事。既然煞車功能無事，又返車房 check 過，forum 上其他同種車主亦有類似問題，咁個人來講，我唔會太擔心囉。

唔知你係咪用返原廠 rotor 同 brake pad？因為好多時候唔同牌子嘅 brake pad 會有啲容易 squeak，有啲會靜啲，完全係睇隻 pad 嘅物料。而一般來講，原廠 pad 通常都會比較靜。

-力

kencyliu

如果是唧唧聲我都唔驚，最弊係格格呱呱聲，非常嚇人，車房話可能是新pads未sit in，但已過了半個月，不但冇減少，還好像嚴重了些。

Catpiano

磨了front rotors及換了front pads ..

How about REAR ???

kencyliu

4# Catpiano
後面冇換過，怪聲不像從後面傳來。

Lik

In that case, could the problem come from the the turned (re-surfaced) rotors?

Generally, I am not a fan of re-surfacing rotors. Coming from a Volkswagen background, the manufacturer has traditionally recommended against re-surfacing their rotors. They seemed to have a reasonable enough excuse for it (even though I forgot what it was), and it seems like their OE rotors are generally pretty durable and resistant to warping as well. Additionally, it always seems to me that turning rotors goes against the logic of using rotors since they are meant to absorb and dissipate heat through the rotor's mass. By turning, re-surfacing, and grinding it down, it seems a little counter-intuitive to me.

(Of course, I understand that it is quite a common practice at various shops... but I digress...)

If you continue to be concerned, I would strongly recommend you to take it to a *DIFFERENT* shop and get a second opinion.

-Lik

字典仔

視乎係咩皮, 有friend比人整完我拆出黎既時候套雜廠皮唔fit, 做成有虛位, 又試過d人冇清乾淨個caliper bracket / 冇lubricate個slider 又或者跟本個slider都未裝好既都有...

我自己屋企都有兩架掃把佬, 磨完碟個brake碟可能隻碟薄左個brake feel都幾"soft", 如果隻碟廿萬都未換過(就算換左一次都係時候再換?), 可能都會導致好多"問題"???

pm me if u need me to help u look at it, can get a third party opinion and see what you can do, doubt the shop will re-do it for free tho...

kencyliu

多謝你們的意見。
我架車楂了十年二十萬Ｋｍ，一共換了三對碟，磨了三次碟，皆因每天要上山落山，以前都會拖吓波，損耗較慢，但有行內朋友話自動波箱有事整一次會好甘，遠比換碟昂貴，所以現在除非很斜都很少拖波。通常一隻新碟年半左右就要磨。磨過之後一年左右就要換，以前從未出現今次的怪聲，遲啲我會攞去再check，攪唔掂惟有再換碟。

shutterbug

It depends on what kind of pads you got there.  Some are noisier than others.  Normal street pads shouldn't be that noisy and the noisy should go away after the pads are warmed up.  For pads, I always go for good quality stuff cuz they are worth the money, noise free and last longer.

If you live on a hill and brake all the time, I wouldn't even surface the rotors, just get new ones.  After you surface them you will warp them sooner than before because of less metal!

Lik

Personally, I wouldn't mind downshifting to a lower gear and take advantage of some engine braking (up to say, 4k rpm). At 4k, you are not really stressing your engine or transmission all that much. Of course, this assumes that the engine oil and transmission oil / ATF are changed on a regular basis to ensure maximum protection of those parts. But everyone has their own preferences as to how things should be done.

-Lik