enzojr

Hi everyone,

One of my rear brake discs have recently become partially dull on the outside half as shown in the pictures below. I spotted it maybe 2 months ago and I've since braked the car from a variety of speeds in a futile attempt to "shine it up" but to no success. When I touch it or rub it, nothing comes off; I could feel that it's slightly rougher in texture than the shiny part but by no means grooved (as what I would expect if there was some metal on metal contact).

Now, there's absolutely no sound from the pads at all and hence I haven't taken the car for any brake service/pad replacement. On rare occasions when I back out of the driveway, there's a bit of squeaking but I emphasize the words "rare" and "a bit". There's also no pull on the steering wheel when I brake and everything feels normal.

What I should also note though is that since I spotted this issue that there have been a significant increase in the amount of brake dust from my rear wheels (both from this rear right brake with the dulled surface, and the rear left brake which is still in perfect shiny condition). I haven't opened up the brake to check how much pad is left (I don't know how and I am not handy) but just eyeballing the visible portion of the pad shows that there seems to still be a good amount left (please see pictures below).

FYI - My car has 84,000 kms, and the rear pads were last replaced at 41,000 kms when there were 2cms left. Fronts were last replaced at 33,000kms if it makes any difference.

My questions are:
1) Can someone speculate on what's going on that led to the dulling of the surface?
2) Is the increased brake dust on the rear wheels an indication that I should change the rear pads?
3) Clearly, I should probably get this brake checked, but does this problem seem like an urgent one to address?
4) What is the likelihood that the brake disc can be resurfaced to make it shiny again? I would like to know whether I should buy a new rotor to bring to my independent but trusted mechanic when I ask him to change all the pads on the car.

Thanks in advance for any advice!

Cheers,
enzojr

Pictures:

Pictures of the dulling of the outer ring:



Close-up of the pad left:


Check out the brake dust after just one week after washing:

huludicidal

That honestly looks like the brake pad tabs are getting hung up and no longer moving freely on the bracket shim. The pictures make it seem that instead of the pads sliding and contacting the full rotor surface under braking, they are just "twisting" a bit and only contacting the inside surface. You should pull it all apart, clean up the shims (so they're nice and shiny) and apply some high temp grease (Honda Urea p/n 08798-9002) to the shims and brake pad tabs. If it were me, since I'm already in there doing the work, I'd just replace the pads since you're almost in need of some new ones.

huludicidal

To address your other questions:

1. see my other post
2. brake dust is not typically indicative of pad life
3. Not terribly urgent since the car brakes fine (I'm assuming). When brakes do this, the pads will wear unevenly and have a shortened life however.
4. Your rotors are pretty rusted and hideous and the rears aren't ventilated. Since they're cheap, you're better off buying new ones than resurfacing the old ones. Also, the lack of "shiny" means oxidation. No matter what brand or style, all rotors will oxidize on their braking surface. Every time you drive the car, you clean off the oxidation by braking. Since the pad isn't contacting the surface properly, you will always have that bit of oxidation.

Remedy: Get new rear pads and rotors. Make sure you (or mechanic) clean and grease the caliper bracket shims properly before installing the pads. Also, since our brakes us a floating caliper, you must also clean and grease up the caliper slider pins (which could also be getting hung up).

Itchytoe

Second picture tells the whole story. See the "lip" on the center of the rotor? You should have one exactly the same size on the top of the rotor too. You have no such lip, which means that your pads are only contacting in the center of the rotor and not at the edges. Judging by the corrosion, it's been like that for a long time.
It is probably a pad/caliper fitment issue. Make sure the pads can move freely. If you take off the caliper (as to change the pads) and the old pads have to be pried out, that's definitely your issue. The old pads shouldn't fall out, but they should slide out easily. Even if they do fall out, it's not a big issue.
I'd suggest a rotor and pad replacement since they're both worn very unevenly. You "could" get away with turning those rotors and getting new pads, but I'd suggest against it. It wouldn't last long and is likely to create more problems than anything else. Then again, I would suggest a rotor and pad replacement for someone who buys a new TSX too, so I may be biast.

enzojr

Thanks very much for your replies! I'll take your advice to heart and bring two pairs of rotors and pads to my mechanic to replace.

Out of curiosity, do you think Honda technicians would go in and lubricate all the brake shims, tabs, and moving parts to prevent issues like this? I've been rather stubborn in not going for the full Service C and D maintenance at the dealer because they are quite pricey.

huludicidal

Well, anyone doing brakes should be doing this. However, taking the time to clean and grease everything is may not be on some mechanic's agenda considering these types of jobs are fixed rate jobs. I would make sure and mention that you specifically want this done.

Kap

I think Itchytoe has got it right. Once your rotor looks like this your not going to get it to wear right even changing pads won't fix it. If your handy change the rotor and pads it's very easy and very cheap, cost is about $60 dollars for a rotor and Ceramic pads per rear wheel. I did mine about 15,000 miles ago and they look almost like the day I put them in nice and shiny and even wear. I take my time and will not trust a mechanic to work on my brakes and have been doing brakes on all my cars for the last 40 years. The fitting of new pads is critical I had to file the rough steel edges on my ceramic pads so they would fit and move as they were meant to. If i didn't do this they would hang up and not retract properly.
If the caliper is at fault I either rebuild that or replace it as the piston needs to retract smoothly too. I lubricate all guide pins, bushings, etc. and finally never seize anything that bolts onto the car and clean up any grease or never seize that gets squeezed out.
I'm fanatical about my cars and bikes and will not have a dealer work on them unless it's something that I simply cannot do. It's not a money issue it's about doing the job right the first time.

pknuts

I vote new rotors. I tried to turn my front rotors. They warped after about 1500 miles. You can get decent rotors from napa for 40$. Its well worth it.

Simba91102

The technicians at a Honda or Acura dealer should do all this if you have them work on your brakes. Dealer shops do tend to be expensive, but I'm reluctant to paint them all with the same dirty brush as some here feel the need to do. If you have the option of choosing between a number of dealerships to have the car serviced, then you can pick and choose. If you're in the same boat as many and only have one local dealer, then you're at their mercy when it comes to service. But.... as with any car and work you can't or won't do yourself, you just have to find a shop that's qualified, you can trust, and is reasonable. Maybe I'm lucky, but I've found my dealer to be all of those things (well, maybe not THAT reasonable....). I feel that there are enough things unique to an Acura (or a Toyota, or a BMW, or a Nissan, etc.), that factory trained technicians at a dealership are my first choice for anything I can't (or don't want to) do. I'm sure that there are plenty of good independent mechanics out there, and I may use one for some things, but I'm not sure I want him fooling with the ABS or VSA, or even bleeding the brakes (for example) on my TSX. As always, my opinion.....

enzojr

Thanks again everyone. I finally found the time to visit the local Acura dealer to get a pair of new rear brake rotors (CAD$89 each with 15% discount) and a pair of new rear brake pads (CAD$68 for the pair). Took it to an independent mechanic without mentioning any of the knowledge from this thread and he said pretty much the same thing, that the caliper pins seized and needed to be cleaned up. He also said that the rotors could not be resurfaced any further as it was pretty thin and would warp easily (after re-checking the previous owner's records, the rotors have actually be resurfaced twice already). So we ended up replacing everything, with the mechanic's labour charge being another CAD$90.

The only curious thing is that the new rotors aren't as shiny as the old ones. There are still shiny, but not mirror-like shiny enough to reflect the wheel spokes...they reflect just the outline of the spokes. Do rotors get shinier over time and use, and if so, what's the "scientific" reason for that? Friction or "glazing effect" from the pad material?

(P.S.: I'm asking because there's a part in me that is paranoid the mechanic took my OEM parts and switched them with aftermarket parts before installing onto my vehicle. I didn't actually physically see the parts being removed from the boxes and onto my car)

huludicidal

Glad you replaced everything, and the mechanic seems competent enough.

As for the rotor shine. Rotors come from the factory with a machined "cross-hatch" finish on the braking surface that scatters light, thus reflecting poorly. (See image)

In about 500-1000 miles, that finish will be warn away and the braking surface will be polished smooth and mirror-like, reflecting more light.