Symptoms of a bad master cylinder?
Symptoms of a bad master cylinder?
Man, am I sorry I ever bought this Olds. Alero 4 years ago. It's giving me nothing but problems.
Issue...
At low speeds, you can hear what sounds like a rubbing noise coming from the right front rotor. This is with NO brake pressue and less than 5 mph. Anything higher, you can't really hear it as engine noise and cabin noise drown it out. When the brakes are applied, this "rubbing" becomes more pronouced. There is no feedback in the steering wheel or the brake pedal regardless of speed; 35mph or 5 mph.
I just replaced the front pads, so that's not it. I TRIED to get the caliper off tonight to see if anything was wrong, but I couldn't get it off!!! Almost like the piston is stuck.
Hence I'm wondering if this could be a master cylinder issue; like it's stuck, or something else.
Thoughts?
Thanks!
Issue...
At low speeds, you can hear what sounds like a rubbing noise coming from the right front rotor. This is with NO brake pressue and less than 5 mph. Anything higher, you can't really hear it as engine noise and cabin noise drown it out. When the brakes are applied, this "rubbing" becomes more pronouced. There is no feedback in the steering wheel or the brake pedal regardless of speed; 35mph or 5 mph.
I just replaced the front pads, so that's not it. I TRIED to get the caliper off tonight to see if anything was wrong, but I couldn't get it off!!! Almost like the piston is stuck.
Hence I'm wondering if this could be a master cylinder issue; like it's stuck, or something else.
Thoughts?
Thanks!
Originally posted by sgmotoring
It is the material in the pads.
It is the material in the pads.
I shouldn't hear a rubbing sound when I'm not on the brakes going 5mph, correct? The pads shouldn't be touching the disc when there's no brake pressue being applied.
I wouldn't be concerned if I was on the brakes, but when I'm not and I'm getting the same noise???
Doesn't seem right.
When I installed the pads, I had no issues like this. I just started happening this weekend.
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I am not sure on Olds. On Acura I see a lot of customers complain about brake squeak and scraping noise after installing aftermarket pads. I don't know what is the right term but in my term the aftermarket pads have too much metal in it(too hard). I see them mostly on pads that carries a lifetime warranty.
GM autos are notorious for that "rubber" sound at speeds 5mph or less when you lightly apply the brakes, or gently let off the brakes. It's the pad material. My friend's 95 Z28 does that, so did our former old-school 70s "boats" (Olds Delta 88 and Omega), even a relative's 01 Suburban and 91 Corsica. To think after all those years, they still haven't got it right.
Oh... and if it really were your master cylinder, your brake pedal travel would actually increase (if your brake fluid reservoir is at the MAX line). IOW, the "grab point" would be much closer to the floor as you depress the pedal.
Originally posted by Roleez
GM autos are notorious for that "rubber" sound at speeds 5mph or less when you lightly apply the brakes, or gently let off the brakes. It's the pad material. My friend's 95 Z28 does that, so did our former old-school 70s "boats" (Olds Delta 88 and Omega), even a relative's 01 Suburban and 91 Corsica. To think after all those years, they still haven't got it right.
GM autos are notorious for that "rubber" sound at speeds 5mph or less when you lightly apply the brakes, or gently let off the brakes. It's the pad material. My friend's 95 Z28 does that, so did our former old-school 70s "boats" (Olds Delta 88 and Omega), even a relative's 01 Suburban and 91 Corsica. To think after all those years, they still haven't got it right.
No Scrib relax...I take it you did not replace the rotors?
Well what happens is the new NEW pads, have alot of material on them... and on ANY braking system where you change the pads or PADS and ROTORS, you will get that rubbing... Trust me, I been doing brake jobs for years, it will go away after the pad wears down alittle...
All brake pads are constantly touching the rotors when they are new... you have nothing to worry about.
Well what happens is the new NEW pads, have alot of material on them... and on ANY braking system where you change the pads or PADS and ROTORS, you will get that rubbing... Trust me, I been doing brake jobs for years, it will go away after the pad wears down alittle...
All brake pads are constantly touching the rotors when they are new... you have nothing to worry about.
did you notice if the front and rear edges of the replacement pads are "beveled". the better quality pads usually bevel the leading and training edges to minimize squeel. particularly during the break-in period, but also for a significant portion of the brake life. if the edges aren't beveled this may give you some squeeling for the first few miles (or first few hundred miles) until the brakes "seat". also, the better pads have integral "shims". these also help minimize squeel. if the pads didn't have integral shims you used to be able buy cheap add-in shims. i've never tried them so i have no idea if they work. but they're cheap and it can't hurt.
also, did you turn or re-surface the rotors. i don't unless the surfaces are severely rough (lots of deep ridges) or a little warped. if they were re-surfaced a non-directional finish will usually resolve any minor squeeling issues until the brakes "seat". if the rotors were resurfaced but without the non-directional finish take the rotors off and have the non-directional finish done. my machine shop will do it for less than $10 per rotor and it can't hurt. note that the shop won't perform a non-directional finish to a rotor that hasn't been turned. so if you didn't have them turned you can't just get the non-directional finish done. its an all or nothing deal.
sorry that the olds is such a headache. i considered the buick regal GS recently but my past experiences with the GM brand was just too aggravating to repeat. hope things don't get any worse.
also, did you turn or re-surface the rotors. i don't unless the surfaces are severely rough (lots of deep ridges) or a little warped. if they were re-surfaced a non-directional finish will usually resolve any minor squeeling issues until the brakes "seat". if the rotors were resurfaced but without the non-directional finish take the rotors off and have the non-directional finish done. my machine shop will do it for less than $10 per rotor and it can't hurt. note that the shop won't perform a non-directional finish to a rotor that hasn't been turned. so if you didn't have them turned you can't just get the non-directional finish done. its an all or nothing deal.
sorry that the olds is such a headache. i considered the buick regal GS recently but my past experiences with the GM brand was just too aggravating to repeat. hope things don't get any worse.
OK, thanks for the feedback all...
According to my wife, the noise is now gone, which is a little confusing.
I was leaning towards thoughts echoed by Smitty, as since the pads are new this is a common thing. I'm going to keep an eye on it and see what happens in the fllowing weeks.
carquest - Thanks for the input. The edges are beveled, and it's really not a squeaking sound. More of a rubbing or grinding at low speeds.
The rotors are fine, IMHO. There's no pulsing or vibration in the brake pedal or steering wheel. I have no problems removing the rotors and getting them turned if need be. I just didn't see a need for it after only 20K miles. They seem to be wearing fine...
According to my wife, the noise is now gone, which is a little confusing.
I was leaning towards thoughts echoed by Smitty, as since the pads are new this is a common thing. I'm going to keep an eye on it and see what happens in the fllowing weeks.
carquest - Thanks for the input. The edges are beveled, and it's really not a squeaking sound. More of a rubbing or grinding at low speeds.
The rotors are fine, IMHO. There's no pulsing or vibration in the brake pedal or steering wheel. I have no problems removing the rotors and getting them turned if need be. I just didn't see a need for it after only 20K miles. They seem to be wearing fine...
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