What are my BRAKE PADS try to tell me? (pictures)

[lazynok]

I went to do a brake job on my car and I found this unusual (well for me) pad wear. What does it mean???

On one corner it is really fat and beefy and on the opposing corner, it is all the way flat to the base. So flat, that it is slicing into the base (you can see on the top-right corner of the 3rd picture, the silver slice)

This is the Rear Driver side, and it is the inside/piston side pad.

Any ideas? Thanks Prime!. I hope its not the piston or something =[

 

[aluminiumdream]

Does the rear brake caliper mount to a caliper braket? if so maybe one bolt came loose. this would cause your caliper to flex when you depress the brake pedel. enough of this and you would have wear like yours.

I do not yet own an NSX but if i did, I would check the following:

!. Check to see if your caliper bracket is on there tight.
2. Measure the distance between the caliper bracket and the rotor. basically check to see if your bracket is parallel to the rotor.
3. measure your rotor's thickness to see if it tapers from the inside of the hub out.
4. check for wear on your caliper guide pins. there could be too much slop between them and the casting.
5. Was one of your pins seized?

I personally think that it is not the piston. I have refurbished enough pistons to say that your caliper is fine. I personally think the caliper mounting is screwed. maybe bent or twisted in such a manner that that the top of your caliper is pointing towards your engine and the bottom is closer to your rotor. I hope this helps...if not.....i will have to buy an X to understand why its doing that.

 

[drew]

Your caliper mounting hardware is probably sticky. Clean and grease the guide pins. Use steel wool to clean out the grooves that the caliper rests on. It doesn't take much friction to cause problems like this.

If the condition persists, then you will need hone the cylinder and replace the o-ring.

Drew

 

[Larry Bastanza]

Make sure you inspect that rear wheel bearing.

HTH,
LarryB

 

[EIFFEL]

The wear indicated is caused by the misalignment of the inner pad and brake caliper piston. It has a nipple on the inner pad backing that must line up with the groove on the brake caliper piston. Could you post a pic of the back of the pad?

 

[OLDMNSX]

After you do all of the above mentioned checks, reinstall the caliper bracket and caliper and check for abnormal wear in the floating pins and sockets in the caliper bracket. Leave the rotor and pads off to do these checks. Make sure that the calipers move smoothly without excessive gyrations. Look at the dust boots for holes or tears. If so you are going to need to replace the boots and pins at the very least, if not the whole bracket. If not clean and regrease with HI TEMP BRAKE CALIPER GREASE. Not too much, just a good coating.

Brad

 

[lazynok]

Thanks everybody for your help! I'll continue working on it tomorrow and i'll check everything you guys have mentioned.

I got a parking ticket today too... damn... right in front of my house... i parked backwards so I wasn't inspecting the driver side brake while sitting in the middle of the road... so much for allocating 1 day to change pads... then this all happens!


You all are making me happy... the guy at pep boys said it was the piston and I would need to rebuild the caliper. I'm glad I asked Prime =] Thanks!

 

[lazynok]

Make sure you inspect that rear wheel bearing.

HTH,
LarryB

Exactly how do I do this? I do everything on my own on all my cars... so the more knowledge I have the better =] Thanks!

 

[chudson1549]

Exactly how do I do this? I do everything on my own on all my cars... so the more knowledge I have the better =] Thanks!

quick method. (wheels mounted) Hands on 12 and 6 oclock try to wiggle the wheel off. hands on 3 and 9 tie rods

 

[Larry Bastanza]

Exactly how do I do this? I do everything on my own on all my cars... so the more knowledge I have the better =] Thanks!

chudson has it correct. The reason I mentioned this is I just repaired a car with the exact same pad wear and the rear wheel bearing was the cause. The wheel was wobbling, therfore the brake rotor was wobbling and caused the uneven brake pad wear.

HTH,
LarryB

 

[lazynok]

Wheel bearing is A-OK... I checked both rear sides also.


I FOUND THE PROBLEM. yay.

The caliper bracket doesn't push against the caliper snugly on the bottom... and it is touching right up to the caliper on the top.

You can see this with the flashlight... the bottom shows light though it.. pretty simple.

I could fit a few sheets of paper through the gap on the bottom... and on the top, and passenger side rear caliper.. i couldn't even fit one sheet.... it fit perfectly.


And this is with me pushing it closed as HARD as I could... and this is the best I could close it.

So something with the pin? A rock inside the boot? The bracket is bent? I guess I'll find out on another day.. thanks for everybody's help!

 

[Daedalus]

That's just plain wrong. Those parts should be match-reamed with a tool and fixture that guarantees they're located right. Did you pull out all the hardware already? How do the slide pins look?

If I thought there was anything up with my brakes I wouldn't drive the car. I found an unseated seal on the caliper of one of my sedans, and the car's grounded until the parts come in and I can properly rebuild the caliper.

 

[lazynok]

That's just plain wrong. Those parts should be match-reamed with a tool and fixture that guarantees they're located right. Did you pull out all the hardware already? How do the slide pins look?

If I thought there was anything up with my brakes I wouldn't drive the car. I found an unseated seal on the caliper of one of my sedans, and the car's grounded until the parts come in and I can properly rebuild the caliper.

Nope, I didn't take anything apart with the caliper. The boots were okay, but I haven't opened them yet. Today, I only wanted to find the problem, and put the disks back on so I could roll the car off the street and on to my drive way so I don't get another ticket.

Yep... this car is not being driven =] Although I did drive it with the noise from that corner of my car for a little bit. It would come and go.

 

[Larry Bastanza]

I think you should try to wiggle the caliper in the bracket. This sure looks like play in the pins/bushings of the caliper bracket. Remember these "float", so they are made to shift around so they clamp on the rotor freely. Frankly, I am thinking you need to check the bracket for eccessive play, and I would clean/regrease the pins before doing anything else, as mentioned above. I would put a new set of pads in and check regularely.

Regards,
LarryB

 

[ChopsJazz]

I think you should try to wiggle the caliper in the bracket. This sure looks like play in the pins/bushings of the caliper bracket. Remember these "float", so they are made to shift around so they clamp on the rotor freely. Frankly, I am thinking you need to check the bracket for eccessive play, and I would clean/regrease the pins before doing anything else, as mentioned above. I would put a new set of pads in and check regularely.

Regards,
LarryB

That is exactly what it looks like to me too. I just did a caliper rebuild on a set of front and rears. There should be NO CONTACT between those parts. Check the 17mm caliper mounting bolts and the 14mm bolts that mount the outer bracket to the caliper.

If there was play, you may have worn your pins to the point of needing replacement.

HTH