C5Lion

I came across a really strangle problem with my passenger side front brake rotor that I would like your opinion on.

Problem - I have noticed a noise from the front passenger side rotor the last 3 days when when pulling out of my driveway and having the wheel turned hard to the right. The noise sounded like something grinding against the rotor and as you will see below, that is exactly what it was.

I removed my caliper last night and found one of the caliper pins was rubbing the rotor. I was going to file down this one pin a little bit to try and solve the problem, but I did not have a file. What I ended up doing was placing 2 pads that were slightly thicker than the ones that I had originally surrounding this pin.

I went for a quick drive and this seemed to solve the problem.

Background Info

1. Just replaced my rotors with brand new DBA4000 rotors. These rotors are going to be for the track.
2. When I changed my rotors I also replaced my street pads with some track pads that only have 1 event on them. Plenty of pad is left.
3. Please note I have never removed the caliper pins since I bought the car 4 years ago. I change the pads by removing the calipers.
4. I have swapped back and forth my pads at least 20 times with no problems.
5. The rubbing only happened when turning the wheel hard to the right.
6. Under normal braking, the pin was not rubbing the rotor.

Any ideas as to why this was happening? I thought maybe that the 2 pistons that surround that pin were stuck, but that did not seem to be the case. I did not see anything out of the ordinary with this particular pin as it did not look any longer than the others.

What is physically happening to the rotor/caliper when the wheel is turned to cause this problem?

PeOR

I know when I am down to minimum pads and turning full, I can usually hear the pads sound against the rotor, something that would not be the case when wheels being straight. I have always thought that is due to the wheel bearing allowing the wheel to flex a few degrees.

But I have never gotten that confirmed.

PeO.

davidfarmer

the caliper and rotor and "fixed" to each other. The problem is that the DBA rotors are probably slightly off center. RB had the same problem with some of their rotors. Filing down the pins is a solution, or shimming the caliper (depending if it needs to go out or in)

longdaddy

I would check for any play or binding/uneven resistance in the hub when you turn it by hand with the wheel and brake rotor off.

but yeah, the simple explanation would be incorrect rotor dimensions

PeOR

This is probably off topic, but I am about to learn something here. David - the caliper is on the spindle side of the bearing and the rotor on the tire side of the bearing, right? Do you mean they are still fixed with regards to each other?

And if the mismatch was like that to start with, would you even be able to turn the wheel by hand?

PeO.

PeOR

Wait - I think I got it. What you are saying is that when the pad is worn down, the pin would access the rotor? But that would not happen until the pad is worn down too much, independently of which rotor. Nope, I still don't get it.

Z11409

We have the same problem with DBA rotors , the rotors are not machined to the tolerances of the stock rotors.If you have your orginal rotors check the back space against the DBA

WE replace the rotors,paint the ends of the pins with machinest blue dye.
Drive it and then check the pins for rubbing.About half of a set of pins will need to be ground down a few thousands of an inch.

bluemagoo

I haven't noticed a difference between my stock and DBA4000 rotors in this regard however your post reminded me of a somewhat similar situation I experienced but with a different cause.

The material my LG spindle ducts are made of (they install between the wheel bearing and spindle) is just a bit thicker than the stock bearing shields which the spindle ducts replaced. I noticed that the rotors (both stock and DBA 4000) were now a bit off-center in relation to the caliper and that the pins came quite close to the rotor face on the outboard side.

Though I didn't have any problems with the pins actually contacting the rotor face even on the track, I eventually installed some thin shims between the caliper and the spindle to recenter things. I obtained some grade-8 hardened washers at the hardware store (approx 9/16" I.D. x 1-1/8" O.D.) and had a friend mill them down to .030" thickness (for my specific situation anyway).

C5Lion

I guess this one DBA rotor may be off center. I just removed a set of DBA rotors. I think I will remove the caliper tomorrow and file down the pins on this side of the rotor.

C5Lion

Its not that since my pads still have a lot of material left.

B505

I just installed the dba 4000 for that same event. Glad to hear you're ok, interested in knowing what you find. I just got my rotors fresh from Aus. through KNS...maybe they fixed the prob?

C5Lion

Go to the post above to see if your rotors fall into the same category. There is a number on the OD of the rotor that will give you some info.

B505

I just changed the rear race pads out last night and did a quick look check on the front rotors. I'll see if I can find that number tonight, didnt get to the post in time.

Dirty Howie

I didn't see this thread till just now. But I did see Leo's other thread about DBA and pin wear.

I started my own threads because I'm getting wear on both front rotors on the inside and outside. But is is much worse on the outsides.These were unused but year 2007 rotors and brand new Hawk Plus pads. I only have 2 days on the rotors put have heavy stress cracks only where the pins are hitting, no where else on the rotor surface. The OEM rotors that I took off just before putting the DBA's on had many track days and NO PIN WEAR !!!

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DH

PeOR

My DBA4000 rotors got engraved by Hawk+ pads when overheating. Stay away from Hawk+ on track. They got my break fluid boiling as well.

PeO.

Dirty Howie

What does engraved mean.

The pads seem to work good. Or maybe its the caliper pins that are helping in the braking zone


DH

DBAsteve

Hi all,

We have posted a reply to this and the other related thread, here.

http://forums.corvetteforum.com/auto...d-input-5.html

Thanks,

DBASteve
dbasteve@dba.com.au