caliper noise

[swerve2007]

obviously nsx calipers are floaters so they may rattle a bit but i just noticed a pronounced 'clunk' coming from my right-front, especially when changing direction (front-reverse etc). i checked for anything obvious like loose bolts but found nothing. i am thinking the pistons are seizing and not fully releasing hence the caliper is forced to move within the little free-play it has. if that is the case, i am a bit surprised to see that so early in car's life ('00, 53k).
anyone seen something like this? any fixes short of caliper rebuild?
thx

 

[Briank]

Are are the stamped sheet metal parts in place and in good condition? Are the back of the pads and shims coated the black grease as they should be?

 

[CL65 Captain]

What pads? OEM?

My Cobalt Sport GTs were slightly smaller than OEM and would clunk over bumps or when changing direction.

Also check the top, bottom and inside (caliper) spring clips. These sometimes wear and the pad will rattle.

 

[swerve2007]

pads are oem, everything is in its place. it really seems like the caliper is grabbing and the floating part of it is moving side-to-side on the pins. wtf?

 

[Briank]

There is very little slop in the pins so it is unlikely your calliper is moving.

 

[swerve2007]

thats what i thought but after examination that is the only place where any motion exists. i am willing to bet the caliper is seizing.

 

[Briank]

Guess you need to pull it and clean and lube the pins. :smile: But I don't expect you will find any problem with them.

Oh re-read the thread, by seizing you mean the pistons thats also unlikelly but get it up in the air and see how the wheel turns, there will be some drag as the retraction in a disk brake caliper piston is only a couple of thousands of an inch.

 

[swerve2007]

thx for reply brian, i did take it all apart already to check so honestly, short of the cylinder seizing up slightly i can't figure it out. there also is an evidence of slightly inconsistent rotor wear (as compared to the other side which is very nice). i wish there was an easier way to eliminate the issue short of taking the caliper apart to clean the guts.

 

[swerve2007]

just fyi, checked everything again and it is caliper seizing that creates the problem. i guess i have to rebuild it unless someone has some tricks up the sleeve.

 

[Briank]

I still don't think you have problem other then a little clunk when the pads shift.

 

[swerve2007]

sorry but no- i have extra wear on the pins as well from the caliper shifting. i would not be freaking out about a little pad noise (and why would it only be coming from that particular location but not others?)- this is a clunk you can hear over the radio. rotor is discolored and worn more than other side too.

thanks for your replies though.

 

[Briank]

rotor is discolored and worn more than other side too.

Should have said that in the first place

 

[swerve2007]

i did in post#8. it is almost unnoticeable difference, something that you would not notice if not looking for, but the seize is not extreme either.

 

[angus]

This is a very normal sound from these calipers , just the pad moving around a bit. I also see it on other honda / acura that use the same pad (D503) .
I do not see it as a symptom of a seized caliper , one thing which is a symptom of a seized caliper would be uneven pad wear.

 

[swerve2007]

i would not be freaking out about a little pad noise - this is a clunk you can hear over the radio. rotor is discolored and worn more than other side too.