Unusually long rotor break in period
10-14-13, 04:33 PM
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Unusually long rotor break in period
To start it off its an 88 gxl with about 106k miles on it. It was at my fathers house during hurricane sandy (he lives in far rockaway) and it was about 6 inches of water/sand. I'll never really know how high it was because i wasn't there during the hurricane.
About 5-6 months ago i did a complete braking system overhaul because the brakes were very bad and most of the pistons had seized up.
Alllll brand new aggressive hawk pads, powerslot rotors, calipers (4 piston), goodridge SS brake lines, new master cylinder, and bled the system about 6 times because it never felt how i wanted it to. And after spending roughly a grand into the brakes i hoped they would perform a bit better than that.
Went to a local 240sx/tuning/mechanic shop i'm cool with and they said to keep driving and let them break in.
Its been about a thousand miles now and they feel OK, theres a lot of play in the pedal still so i was looking into buying a MC brace (my booster and mc move under hard hard braking)
I can easily lock up my front wheels and they work great on the highway so i had assumed they finished braking in. I was cleaning off the massive amount of brake dust on my wheels and noticed my rotors look a bit funny....
My front rotors seem to be 1/3 shiny and 2/3 matte colored. as if theres some kind of layer on them.
Same story with the rears. 1/4 shiny 3/4 matte
Roughly how long should it take to break in the rotors/pads??? on every other car i've had i've gotten them to break in after 100 miles not a thousand. What could be wrong with my braking system?
Thanks in advance!
About 5-6 months ago i did a complete braking system overhaul because the brakes were very bad and most of the pistons had seized up.
Alllll brand new aggressive hawk pads, powerslot rotors, calipers (4 piston), goodridge SS brake lines, new master cylinder, and bled the system about 6 times because it never felt how i wanted it to. And after spending roughly a grand into the brakes i hoped they would perform a bit better than that.
Went to a local 240sx/tuning/mechanic shop i'm cool with and they said to keep driving and let them break in.
Its been about a thousand miles now and they feel OK, theres a lot of play in the pedal still so i was looking into buying a MC brace (my booster and mc move under hard hard braking)
I can easily lock up my front wheels and they work great on the highway so i had assumed they finished braking in. I was cleaning off the massive amount of brake dust on my wheels and noticed my rotors look a bit funny....
My front rotors seem to be 1/3 shiny and 2/3 matte colored. as if theres some kind of layer on them.
Same story with the rears. 1/4 shiny 3/4 matte
Roughly how long should it take to break in the rotors/pads??? on every other car i've had i've gotten them to break in after 100 miles not a thousand. What could be wrong with my braking system?
Thanks in advance!
10-14-13, 07:31 PM
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the rear calipers have sliders, you should at least pull a wheel and see if they move by hand.
for the front, i just looked at a friends car, and his new pads didn't slide very freely in the calipers, so i actually sanded the edge down a little. IMO on a race car you want em loose in there so everything can move when its HOT, however on the street this is noisy, so snug might be better.
the problem with his car was actually an imploding brake rotor, it came with a vibration that felt like certain death, similar wear pattern.
you might also check the wheel bearings too, if there is too much play, the pedal will feel lousy and the brakes might wear funny like that
for the front, i just looked at a friends car, and his new pads didn't slide very freely in the calipers, so i actually sanded the edge down a little. IMO on a race car you want em loose in there so everything can move when its HOT, however on the street this is noisy, so snug might be better.
the problem with his car was actually an imploding brake rotor, it came with a vibration that felt like certain death, similar wear pattern.
you might also check the wheel bearings too, if there is too much play, the pedal will feel lousy and the brakes might wear funny like that
10-14-13, 11:55 PM
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Its a possibilty that these rotors weren't machined and the play could be from them not bedding in correctly... Heat spots as in? Maybe you're seeing the water / soap / simple green? I took the photos while washing my car.
The correct way to bleed the brakes is the 4 wheel wells right? I don't have to touch any 3 way valves or proportioning valves do i?
the rear calipers have sliders, you should at least pull a wheel and see if they move by hand.
for the front, i just looked at a friends car, and his new pads didn't slide very freely in the calipers, so i actually sanded the edge down a little. IMO on a race car you want em loose in there so everything can move when its HOT, however on the street this is noisy, so snug might be better.
the problem with his car was actually an imploding brake rotor, it came with a vibration that felt like certain death, similar wear pattern.
you might also check the wheel bearings too, if there is too much play, the pedal will feel lousy and the brakes might wear funny like that
for the front, i just looked at a friends car, and his new pads didn't slide very freely in the calipers, so i actually sanded the edge down a little. IMO on a race car you want em loose in there so everything can move when its HOT, however on the street this is noisy, so snug might be better.
the problem with his car was actually an imploding brake rotor, it came with a vibration that felt like certain death, similar wear pattern.
you might also check the wheel bearings too, if there is too much play, the pedal will feel lousy and the brakes might wear funny like that
As i said i did a complete overhaul of the braking system, remans from napa that i made sure all the pistons moved and i greased up the sliding pins and confirmed they had free play
For the fronts i was given all new sliding pins as well which i greased up and were also easily sliding. I'll look into the wheel bearings though, i messed up my old knuckles/hubs while trying to get my old 25!! year old rotors off. So i got knuckles off a part out and used them. Can i swap my old hubs onto new knuckles? I didn't think that would have that much of an impact on brake pedals
How do i check if my check valve/booster valve or whatever its called and see if its functioning correctly? Didn't his problem ending up being a bad reman? I got a brand new master not a reman
What would you recommend? I'm not gonna go and throw out brand new pads but i'll keep it in mind when i have to replace these
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