New brakes did something weird today
#1
New brakes did something weird today
Driving down a hill for about a mile with about 7 stop signs. Fairly good grade but not extreme. Wasn't going fast in between, maybe 40 at the most, probably 30 mph mostly.
By the time I got to the bottom, my brakes had faded considerably and the front were smoking. I could smell hot brakes. The car did not pull to either side and seemed to coast just fine (no binding I think).
Front disc / rear drum - factory stuff.
I just finished doing:
new/rebuilt calipers (AC Delco)
new/rebuilt wheel pistons (Dorman)
new AC Delco pads front and back
new brake lines in the front
fluid flush and bleed.
The original fluid was old and brown with stuff floating in it, FYI.
I'm pretty sure the car has better brakes than this. I'm thinking maybe my combo valve is bad or the MC but the car seems fine in normal street driving.
Any ideas?
By the time I got to the bottom, my brakes had faded considerably and the front were smoking. I could smell hot brakes. The car did not pull to either side and seemed to coast just fine (no binding I think).
Front disc / rear drum - factory stuff.
I just finished doing:
new/rebuilt calipers (AC Delco)
new/rebuilt wheel pistons (Dorman)
new AC Delco pads front and back
new brake lines in the front
fluid flush and bleed.
The original fluid was old and brown with stuff floating in it, FYI.
I'm pretty sure the car has better brakes than this. I'm thinking maybe my combo valve is bad or the MC but the car seems fine in normal street driving.
Any ideas?
#2
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Re: New brakes did something weird today
Stock pads and dinky 10.5" rotors, what you experienced is normal. Had the pads been bedded prior to this?
RBob.
RBob.
#3
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Re: New brakes did something weird today
Did you just slap new pads on old glazed rotors and hit the road? Generally you want to have the rotors resurfaced or replace them, and bed the pads to them shortly after replacing so they wear together. Regardless smoking is a bad sign.
Typical stock thirdgen brakes aren't the best, but they shouldn't be fading under normal conditions.
Typical stock thirdgen brakes aren't the best, but they shouldn't be fading under normal conditions.
#5
Re: New brakes did something weird today
Thanks everyone. I did reuse the rotors that were on the car. They were straight and didn't have much of a lip on them. But now I'm thinking maybe they were glazed over.
Do you suggest I turn or change the rotors and the pads or just the rotors? Have I ruined the new pads? What do you think about the rear drums? I did not have those turned either.
Do you suggest I turn or change the rotors and the pads or just the rotors? Have I ruined the new pads? What do you think about the rear drums? I did not have those turned either.
#6
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Re: New brakes did something weird today
Did you replace the hoses? I ask because hoses on these cars have a habit of rusting internally, and then they get blocked. What can happen is fluid will push through under pressure, but then it won't release so the calipers stay clamped.
Pull the calipers and inspect the pads and rotors. Grooves would be bad. Signs of excessive heat would be bad. If the pads look evenly worn, and the rotors are still true, you might try buzzing the surface of the rotors with a fine 3M roloc disc to break the glaze. Or have the rotors turned and they should give the surface the same treatment. Really though, for the cost of rotors there's not much reason not to replace them. A fresh, new rotor has more mass than an old one that's been turned. More mass means more capacity to absorb and displace heat.
Pull the calipers and inspect the pads and rotors. Grooves would be bad. Signs of excessive heat would be bad. If the pads look evenly worn, and the rotors are still true, you might try buzzing the surface of the rotors with a fine 3M roloc disc to break the glaze. Or have the rotors turned and they should give the surface the same treatment. Really though, for the cost of rotors there's not much reason not to replace them. A fresh, new rotor has more mass than an old one that's been turned. More mass means more capacity to absorb and displace heat.
#7
Re: New brakes did something weird today
Yeah. I'll just buy new rotors and drums.
I replaced the two brake hoses to the calipers. The rear hose to the drums was being stubborn so I left it in. It looked OK as far as outside rubber-wise.
I must've flushed at least a quart of new fluid through the front and back using a vacuum bleeder and then topped it off.
I replaced the two brake hoses to the calipers. The rear hose to the drums was being stubborn so I left it in. It looked OK as far as outside rubber-wise.
I must've flushed at least a quart of new fluid through the front and back using a vacuum bleeder and then topped it off.
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#8
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Re: New brakes did something weird today
Did you replace the hoses? I ask because hoses on these cars have a habit of rusting internally, and then they get blocked. What can happen is fluid will push through under pressure, but then it won't release so the calipers stay clamped.
Pull the calipers and inspect the pads and rotors. Grooves would be bad. Signs of excessive heat would be bad. If the pads look evenly worn, and the rotors are still true, you might try buzzing the surface of the rotors with a fine 3M roloc disc to break the glaze. Or have the rotors turned and they should give the surface the same treatment. Really though, for the cost of rotors there's not much reason not to replace them. A fresh, new rotor has more mass than an old one that's been turned. More mass means more capacity to absorb and displace heat.
Pull the calipers and inspect the pads and rotors. Grooves would be bad. Signs of excessive heat would be bad. If the pads look evenly worn, and the rotors are still true, you might try buzzing the surface of the rotors with a fine 3M roloc disc to break the glaze. Or have the rotors turned and they should give the surface the same treatment. Really though, for the cost of rotors there's not much reason not to replace them. A fresh, new rotor has more mass than an old one that's been turned. More mass means more capacity to absorb and displace heat.
If the OP just put new pads on old rotors, then what he did was partially bed the brakes in. He wore off the anti-rust coating most likely. And that was what was smoking.
They will likely be fine given a proper bedding.
#10
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Re: New brakes did something weird today
did you wash them down with brake cleaner? If you didn't, they still had the Zinc coating on there to protect the rotor from rust. Plus the oils that also are on the rotor to protect it while in storage.
That oil will make a SMELLY mess.
That oil will make a SMELLY mess.
#11
Re: New brakes did something weird today
Well, I'm using the old rotors. They looked good, but now I'm thinking they were glazed. Do I need to replace my new pads now (maybe 50 miles on them) or will they go with the new rotors (or sanded existing rotors) just fine?
#12
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Re: New brakes did something weird today
I too have faded the stock OEM brakes, it didn't take much. At a minimum the OP should upgrade the pads.
RBob.
Last edited by RBob; 03-20-2017 at 08:19 PM.
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Re: New brakes did something weird today
RBob.
#14
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Re: New brakes did something weird today
I got my first thirdgen when I was 17, and had at least three by the time I was 21. Even being a master of the jackrabbit start, driving crazy, and standing on the brakes at every stop, I never had a brake issue worthy of a thread post. To get smoke usually takes some serious abuse, like a panic stop from high speed, or a mechanical failure, like a locked up caliper as I mentioned earlier.
Fade serious enough to warrant a thread, and smoke, after a handful of 40mph stops is absolutely not normal.
If the rotors do look to be glazed, most auto parts stores, carry a 3M refinishing kit that can be used with a drill, or better yet an air angle grinder. Harbor Freight sells a cheap version of the same thing, and I think I've even seen the 3M sets on the shelf at Walmart. It doesn't take much, you're just looking to give a non-directional tooth to the rotor surface that the pads can wear to evenly. Like the hone crosshatch in a cylinder, or the random pattern on a new rotor. You can probably accomplish the job with regular sand paper, but where's the fun in that?
The stock brakes really aren't that bad, but they don't leave a lot of room for an error like slapping new pads on old glazed rotors.
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Re: New brakes did something weird today
If the rotors were glazed, the OP would have had the opposite problem, very low braking effort. He would have been rolling through the stop signs.
As for the smoke, why not, the pads weren't bedded. On top of that, how much was the OP riding the brakes on the down hill slope (fairly good grade) to keep the speed down?
RBob.
As for the smoke, why not, the pads weren't bedded. On top of that, how much was the OP riding the brakes on the down hill slope (fairly good grade) to keep the speed down?
RBob.
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Re: New brakes did something weird today
Get a set of the StopTech High Performance street pads (D154 form) and install those. Need to bed the pads, StopTech has a white paper section that describes how to do this. It is making controlled near stops to transfer pad material to the rotor and to bake the resins used to hold the pad material together:
http://www.stoptech.com/technical-su...and-procedures
Then enjoy the better brakes.
RBob.