Brakes Problem, Squeeking Sound.

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hello vtec sifu's. i have a minor problem, but its annoying as hell. i hope u guys can help me as i have exhausted my mech's brains. lol

initially my rear calipers jammed up. so i got it serviced. it wasn't jammed after that, but my brakes squeek when i pump the paddle.

brought it to another workshop (more known for their vtec works), mech couldn't find the source. so asked for my permission to change parts. so changed the master pump, changed the valve stopper and even changed the jammed calipers.

still squeeking. what else could it be?

my car had ABS initially, after conversion, i'm running on eg6 front rotors, so tarak ABS. could it be the ABS pump? or what else could it be?

pls help me...

 

[shiroitenshi]

Squeaking, hard to trace without seeing.

but if possible, then take out your wheels and observe the clearance of the calipers, the condition of the rotors and such.

Squeaking is commonly from the rotors or the pads, although occasionally a warped disc can cause noise too.

Hard to pinpoint the source without looking.

 

[arrowhead]

Squeaking, hard to trace without seeing.

but if possible, then take out your wheels and observe the clearance of the calipers, the condition of the rotors and such.

Squeaking is commonly from the rotors or the pads, although occasionally a warped disc can cause noise too.

Hard to pinpoint the source without looking.

how big should the clearance of the calipers be? and whats a warped disc? :hmmmm::hmmmm:

 

[shiroitenshi]

Borrow from wikipedia.. lazy to type
Warping

Warping is often caused by excessive heat. When the disc's friction area is at a substantially higher temperature than the inner portion (hat) the thermal expansion of the friction area is greater than the inner portion and warping occurs. This can be minimized by using "floating" rotors which decouple the friction area from the inner portion and allow thermal expansion to occur at different rates. Primary causes of overheating include undersized or overmachined brake discs, excessive braking (racing, descending hills/mountains), "riding" the brakes, or a "stuck" brake pad (pad touches disc at all times).

Summary : Disc brake is not flat anymore.

Read this too, if you like, but do note that he calls 'warped discs' a MYTH, because he's not referring to the standard one piece brake rotors, but the two piece type, which is severely warp resistant if mounted properly.
http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

Usually if the sound comes from brakes, taking out the wheels and doing visual inspection, will notice where the noise is coming from, esp. if a part is touching places that it's not supposed to touch

Of course, after all that, it could also be a dying wheel bearing.

Too many possibilities to consider.

 

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thats the problem shiro. we've pretty much removed the front/rear wheels and listen as we go into the fenders (LOL) and we still cant identify the source.

my mech said its coming from the engine bay. things gets worst because my engine has to be running in order to hear it squeek.

wheel bearing? pumping brakes affect the wheel bearing and it causes it to squeek? hmmm... i think i should tell this to my mech and see what he has to say.

 

[shiroitenshi]

thats the problem shiro. we've pretty much removed the front/rear wheels and listen as we go into the fenders (LOL) and we still cant identify the source.

my mech said its coming from the engine bay. things gets worst because my engine has to be running in order to hear it squeek.

wheel bearing? pumping brakes affect the wheel bearing and it causes it to squeek? hmmm... i think i should tell this to my mech and see what he has to say.

Well, the wheel bearing should be accompanied by other symptoms so it's usually easy to locate... depends on the severity of the damage on the bearing.

But depending on the squeak, it could be the belts/pulleys also. This is where your skills in identifying the noise will help.

 

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:hmmmm::hmmmm::hmmmm::hmmmm::hmmmm::hmmmm::hmmmm: all i can say is.... thanks... and god bless me.

 

[shiroitenshi]

If cannot hear, cannot know lah.
since you're not even sure where the sound come from.. what to do?

If it's so hard, try push the car, and listen to squeaks. if got, it's likely to be the something that's not engine related making the squeak (obviously this is not a one-two men job) usually need maybe 3 peple.. 2 people push car, one guy go and listen (or two only if one is very strong). (It needs to get to a decent speed so notice that this also takes up a lot of space, so depends on your mech's working area. You can also start the car and drive around slowly while the guy runs along outside listen to the differnt parts, but if you're using a loud exhaust, maybe it's better to push.. But I choose pushing because I want to eliminate noice from engine. so if only the knuckles or whatever noise appears, I won't confuse with engine sound.

Cannot find the noise and suspect it's the engine? or suspect the sound can only be heard when driving a little faster?

then take out four wheels and put on jack stands.
start engine and let it coast on 1-2nd gear like when doing brake skimming.
listen to squeaks. (this is to test the brakes to see if they are rubbing or not, but this is not a 100 % test because there is NO LOAD on the bearings. But this is also the part where you check if the sound is coming from engine, as you can rev it to the RPM where the sound occurs.
You can also mount tires or or not remove them, but removing the tires reduces the load so you can identfy the sound better, and you can put your ear nearer to the fender without risking rubbing your face on a TE37 or a CE28 Ha ha.

But either way, usually this does the trick. If you need to simulate load on one of the wheels, just use a jack to jact up the lower arm a bit. you can do this one at a time.


If you have the 2 post lift, it's easier as you don't need to use the jackstand.. but remember not to overzealously rev the car.. 2 post lift is less stable than a 4 post lift. In my case, I have access to a 4 post lift only, so have to use jackstands.

Usually either of this methods will narrow down the problem and locate.. Usually I don't need to go so far and do all of them, because the sound usually gives enough clues to skip either one.

If after that still cannot locate.. I think probably suspension, or you should look for someone with better hearing ability. :P

Good luck

 

[arrowhead]

nono shiro u got it all wrong. the squeeks can only be heard when the engine is on, not while the car is moving/driving.

when the engine is on idle, the car is stationed, pump the paddle and there is squeeks. if the engine is off, the brake paddle just becomes hardened till there's no way u can pump that.

anyway i'll let my mech know of what u mentioned. thanks again.

 

[shiroitenshi]

If like that, it's likely to be some part of the brake system. The pedal usually don't become hardened to that point unless you pump it lots of times, which is natural, since when the engine isn't running, the vacuum assist from the manifold is not there.

But are you sure the noise isn't there when moving? it might have been masked by other engine noises, which is why I do the pushing test.

Could be a jammed caliper piston, but that one needs visual and manual checking of the brake piston seals to confirm.

 

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i cant test when the car is moving cuz i have to pump the paddle, i will vomit if the car is moving LOL.... can only be done when its stationary with the engine running, pump the paddle and WAHLAH... squeek squeek!

i'll get my mech to check the pistons.