Puzzled by brake noise after new install......help please

[Dave M]

Good evening folks,

I completed a complete brake replacement a week ago. Meyle discs, Akebono pads all around (BMA). Everything went fine except one of the front inner pads had a bent spring steel thing-ma-jig and I had to bend it back to hold within the piston. It wasn't perfect and didn't fit as snug as the other side, but it did stick when jammed in there.

Anyhow, since the job, I've had a mild knocking from the front end with each wheel rotation under moderate to hard braking. There is no vibration or movement at the steering wheel that one would associate with a warped rotor, nor is there any significant knock at the brake pedal (if there is, it is so subtle that its difficult to discern). I got under the vehicle yesterday and double checked the caliper and carrier plus other suspension related stuff. Everything was fine, both front wheels spin as they should with no sticky spots and the rotors appear clean as a whistle.

Any thought or magic bullets welcome,

D to the ave

[ahlem]

Was there a set of instructions on how to bed the pads in the rotor box? Some call it heat cycle. You might have been too timid. I had to scuff sand a set of pads to de-glaze them and start over to bed them in properly. Assumptions here that you have good calipers and lubed the pins and back of the pads. Been there done that.

[Tiger]

That knocking has nothing to do with your brake. You did a great job.

Your ball joints are bad. The question is which one? What mileage do you have on your car now? What is the last time you changed your upper control arm, lower control arm and sway bar links?

[Dave M]

Hmm, sounds plausible, but why only after the job was done and why on every wheel revolution? I don't hear any clunking over bumps or experience any shimmy. Anyhow, I did the uppers in 2004 or ~ 100,000 km ago. The lowers haven't been done since I've owned it (2002). So, again, quite plausible its in need of some attention. I'll have a good look this weekend.

Thanks Tiger,

Dave

[Tiger]

With each wheel rotation? a knock? Even when the car is up in the air and you spin the wheel?

[Dave M]

With each wheel rotation? a knock? Even when the car is up in the air and you spin the wheel?

Sorry, I'll clarify. The knock is only when driving and when moderate to hard braking is occuring. No noise when spun freely on jack-stands.

Thans again for your help

[genphreak]

Perhaps try cleaning both sides of the discs before ordering new joints or arms... a greasy patch may cause unexpected outcomes (though sounds unlikely)!

[Tiger]

Ball joints... your braking is quicker, harder and faster... enough to provoke a knock.... whereas your old brake was slower and not as jarring to cause a knock.

Most of time when knocking under brake is lower ball joint... upper ball joint knocks when going up your driveway ramp from street or going down.

Sway bar links knocks when you hit a hard bump on one side... which does cause knocks on lower control arm...

When you jack up car... and on jack stand... grab 12 and 6 o clock... rock it... if you got movement... lower control arm ball joint is shot.

[Dave M]

Ball joints... your braking is quicker, harder and faster... enough to provoke a knock.... whereas your old brake was slower and not as jarring to cause a knock.

Most of time when knocking under brake is lower ball joint... upper ball joint knocks when going up your driveway ramp from street or going down.

Sway bar links knocks when you hit a hard bump on one side... which does cause knocks on lower control arm...

When you jack up car... and on jack stand... grab 12 and 6 o clock... rock it... if you got movement... lower control arm ball joint is shot.

Sounds like a plan Tiger, will look at it soon and be sure to post back.

Thanks yet again,

Dave

[Dave M]

Perhaps try cleaning both sides of the discs before ordering new joints or arms... a greasy patch may cause unexpected outcomes (though sounds unlikely)!

I was pretty carefull and cleaned rotors with acetone after installing. You never know though.............

[632 Regal]

Back up slowly and jab the brakes lightly, you will know if you have a loose balljoint. (in addition to the knock of small bumps in the road)

[Dave M]

Back up slowly and jab the brakes lightly, you will know if you have a loose balljoint. (in addition to the knock of small bumps in the road)

Yeah, no such luck. I've removed the carrier, check pad placement, cleaned rotors etc. I called Patrick and ordered upper and lower control arms plus some other needed bits. As I posted, I've never done the lowers and the uppers have 100,000+ km on em, so they're due.

Thanks for the advice Regal,

Dave

[genphreak]

Ya! I usually get someone to drive the car back and forth a foot or two jabbing the brakes- when standing beside it watching a front wheel for movement it is quickly apparent when a joint is wobbly.