ronarndt

I have been chasing an annoying problem on the front brakes of my 68 convert. The car pulled hard to the right when the brakes were applied in a hard stop. Bleeding the brakes did not show any trapped air. I have drilled/slotted rotors and Hawk pads and recently replaced the left front caliper with ss sleeved , since I thought it had rust in the piston cylinder and was not fully extending, especially since the wear pattern on the rotor showed the pad was not hitting the full width of the rotor. Today I checked the flatness of the rotor and brake pad with a machinist straight edge. The rotor was ok, but the pad had a crown on the surface of the lining that was not wearing down and seating, despite countless hard stops from 60 mph. So I used 80 grit sandpaper on a flat surface and trued up the flatness of the brake pad. Now the pad contacts the rotor properly and applies the same amount of friction as the other side brake. The car now does not pull and stops straight. So- the Hawk pads were ok for three of the brakes, but one pair did not get machined flat by the manufacturer.

Peterbuilt

We don't need any stinkin' quality control!
We make the good enough!

ignatz

I buy Hawk pads all the time, never a glitch but now I will inspect each. Thanks for sharing the solution.

Buccaneer

I run Hawks as well, nice find and fix.

Tampa Jerry

Keep an eye on the rotor. It is not a good practice to sand a pad with sandpaper. The abrasive can embed itself into the pad and cut or groove the rotor. Next time use a clean file. I would have sent it back to Hawk. I use them and like them, but accidents happen. Jerry

ronarndt

I would have sent them back also, except they have been on the car for over two years. Don't think they would have accepted them. You are right about scoring the rotor. There is a minute scratch that I hope will wear itself away from my $lotted, drilled cryo-treated rotor$

ignatz

I have an old set of pads that I reinstall with emery cloth attached and run the car up and down my street to take off the old glaze by lightly touching the brakes. I am not necessarily endorsing this, but it beats the alternatives and takes care of both sides of the rotors. Nary a problem have I ever had with embedded abrasive, but I will watch for it.

69autoXr

Brake pads on these cars typically wear the leading and trailing edges more than the center. Pads pulled off after wear will not be flat. Not necessarily the fault of the pad manufacturer. I've sanded pads back to flat many times.

J56 twin-pin pads had a bend over the top of the backing plate to help stiffen the pad and reduce the goofy wear.

ignatz

Just to keep the tradition of interminable posts on brakes alive, I will add to this thread. The Wilwood 6-piston front option, properly installed, left-to-right helps mitigate the uneven wear by putting the bigger piston in (I'm guessing here) the trailing position. I don't think I've ever seen uneven wear in the rears. I did get a stuck piston up front once and the uneven wear was pretty phenomenal. Wilwood was pretty good about quickly replacing that caliper and I think I even got free shipping both ways!

ronarndt

Based on the wear pattern on the pads and rotor, only about 50% of the pad (only in the center of the pad) was touching the rotor. All of the other three wheels had normal wear patterns. I recall there was one brand of pads (forget which one) that advertised they curved the pads so they would wear in quicker. Anyway- it looks like I have this problem fixed.