In our last installment, I rebuilt my Subaru brake calipers and replaced the pads with some new Hawk HPS performance pads. I was disappointed that after all that work and money that my braking performance hadn’t changed all that much.
It was while I was posting that article that I noticed, in one of the pictures, THIS:
See that groove at all along the top of each of the old brake pads? I never thought much about it, while I was looking at them in person. When I saw the picture, I realized where all my braking performance had gone. The reason for those grooves is this corresponding ridge on my rotors.
It seems that whatever brake pads were installed in this car when it lived in Japan were a little undersized. This wore the disc unevenly, and when I put on new full-sized pads they were riding on that rusty ridge instead of on the disc.
The proper thing to do here would be to replace the rotors. But.. am I made of money? Last I checked, no. The next best thing to do would be to take the rotors to be resurfaced/turned - but if I were to do that, I’d be halfway (money-wise) to a set of new rotors. What is a cheapskate to do? DIY!
Off came the rotors, and out came my angle grinder.
Some very careful grinding ensued, followed by the flat edge of a file to make sure it was flat.
Finished outside face:
And (slightly rustier) inside face:
A squirt of brake cleaner and they were ready for re-installation.
I re-burnished the pads (if that’s even possible) by repeating the procedure outlined by Hawk: 10-ish moderate 50kph stops, 2-ish hard 70kph stops, followed by a cool-down.
I followed that up with a quick (but spirited!) test drive, and my first impression is that my braking feel and performance have increased by a fair margin. I expect that when the pads have worn flat again and make full contact with the newly-flattened rotor, I should even get a little bit more out of them. A nice and unexpected side effect is that my very minor brake pulsation has disappeared!
It was while I was posting that article that I noticed, in one of the pictures, THIS:
See that groove at all along the top of each of the old brake pads? I never thought much about it, while I was looking at them in person. When I saw the picture, I realized where all my braking performance had gone. The reason for those grooves is this corresponding ridge on my rotors.
It seems that whatever brake pads were installed in this car when it lived in Japan were a little undersized. This wore the disc unevenly, and when I put on new full-sized pads they were riding on that rusty ridge instead of on the disc.
The proper thing to do here would be to replace the rotors. But.. am I made of money? Last I checked, no. The next best thing to do would be to take the rotors to be resurfaced/turned - but if I were to do that, I’d be halfway (money-wise) to a set of new rotors. What is a cheapskate to do? DIY!
Off came the rotors, and out came my angle grinder.
Some very careful grinding ensued, followed by the flat edge of a file to make sure it was flat.
Finished outside face:
And (slightly rustier) inside face:
A squirt of brake cleaner and they were ready for re-installation.
I re-burnished the pads (if that’s even possible) by repeating the procedure outlined by Hawk: 10-ish moderate 50kph stops, 2-ish hard 70kph stops, followed by a cool-down.
I followed that up with a quick (but spirited!) test drive, and my first impression is that my braking feel and performance have increased by a fair margin. I expect that when the pads have worn flat again and make full contact with the newly-flattened rotor, I should even get a little bit more out of them. A nice and unexpected side effect is that my very minor brake pulsation has disappeared!
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