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Discussion Starter #1
Folks, I am new here, and it looks like I'll be keeping my Scooby do for the forseeable future. I just dropped a couple grand into it at 180,000 miles. New brakes, calipers, pads and rotors all around, all ball joints, tie rods and a CV joint/axle, as well as struts. Even spark plugs. But.....

I have this one vexing problem. Way back when I first got it at 50K, I replaced the front brakes due to pulsing. After a few weeks, it came back and has remained. I recently did them again. No pulsing, and after a few weeks, the pulsing is back. I've just lived with it, but this is tiresome, especially after dumping a couple grand into it.

Anyone else had a similar issue? Is this a curse on this model, or is there a fix?

Lovin Life,

Bob
 

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How fast is the pulsing?

If you have gotten the brakes hot and then come to a stop with the brakes on, pad material can transfer to the rotor causing a pulse (once per wheel revolution), but this pulsing is a good bit lower in rate than from a 'warped' rotor.
 

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caliper pins, boots, etc need to be clean, no rips, properly greased.

the 02's have those stupid slide pin bushings on them that hang in the slide pin bores. this can cause the pad to hang on the rotor...generating heat and causing issues. i remove all of them, i don't even install them i've seen this happen so often. Subaru never had those bushings for 30 years, i don't care to remove them now!

Newer Subaru's do tend to have more issues with rotors. I'm not sure if it's an issue or what - it may simply be because everything is getting bigger - newer Subaru's are far bigger, heavier, larger wheels/tires, and have larger brake systems on them - maybe they're getting taxed more?

Maybe cheap rotors?

Some folks suggest turning the original Subaru rotors rather than replacing them since they are made with higher quality metal than the cheap autoparts chinese recylced washers and dryers.

I've had more problems with mine of the same generation as yours as well.
 

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If you're forced to drive in traffic conditions that are prone to causing you to make emergency/'urgent' stops - then sit with the brakes clamped on the rotors - you will probably always have rotors that pulse. When brakes are hot, then have their pads held in one spot, pad material can transfer in that spot under the pad, leading to part of the rotor surface presenting more friction than the rest of the rotor's surface. This is felt as a pulse. The rotors are rarely actually 'warped' and sometimes a 'bedding in' process will remove the problem. Sometimes having rotors turned will as well. In more rare circumstances, the heat is so extreme the rotor alloy changes and likely the rotor will need to be replaced.

if steering/suspension parts/bushings, or tires, or alignment are suspect - the problem can be exaggerated.

you might read some here;

-Warped- Brake Disc and Other Myths

Bed-In Theory
 

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What about changing the brake fluid? I remember my wife's Cavalier was pulsing on the brakes until I had the brake fluid changed. I'm honestly not sure if this is your problem....just throwing an idea out there.
 

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Discussion Starter #6
All good suggestions

I have pretty much done all you folks are suggesting. When the calipers got changed, all the fluid was drained. Checked for greasing parts, etc. took them apart again and double checked, no change.

Back at 50K the original ( I suppose) rotors were pulsing quite a bit. I used replacement OER rotors then and now (180 K). Not a lick of difference in either case. Maybe Subaru rotors are better, but they were pulsing good at 50K. I don't have much city traffic, and normally don't need emergency stops.

I'm just a tad hesitant to go out and buy another set of rotors just to test the theory, but I may...

Many thanks. Any more suggestions?
 

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are the pads wearing evenly? (inside/outside as well as left wheel to right wheel)

what brand of pads have been tried?

have you tried a bedding in procedure? (even 30 medium/hard stops, from 30mph, with 30 seconds of driving in between each stop - might be enough to even-out pad deposits)
 

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not familiar with silverline, brief search seems to indicate they may be no better than 'ok'.

try a bed-in procedure. If you're still disastisfied, you might consider Centric Posiquiet Ceramic pads for OEM-type performance at an affordable price. There are other choices too. OEM is good stuff (probably Akebono) but pricey.

the fact that the pulsing is gone/reduced after brake work, then seems to return, sorta points to uneven pad deposition and lets most of the ideas about tires or mechanical wear off the hook. If you aren't doing a panic stop, and no one else driving the car does, and if there's no dragging brake pad from a sticking caliper - then what you are experiencing is a random uneven pad deposition that some folks experience from light brake use. Could be made worse with some pads vs others, but often a quick bed-in procedure will clear it up for a while. Try the 30-30-30 deal I mentioned up in post #7. If the pulsing gets worse - you may already have cementite areas on the rotors and they likely need to be changed. If it gets better but isn't quite gone, you may benefit from a more aggressive bedding-in procedure.
 

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Discussion Starter #12
I started to do this and I was sensing some improvement, but I was making my passenger seasick, so I stopped. Today, I'm going out alone, so I'll do it but good! As I was doing this, I could hear some grinding on the front right brake. I'm guessing this was the start of the cleaning up??? Anyways, I'll give it a good shot today.
 

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I started to do this and I was sensing some improvement, but I was making my passenger seasick, so I stopped. Today, I'm going out alone, so I'll do it but good! As I was doing this, I could hear some grinding on the front right brake. I'm guessing this was the start of the cleaning up??? Anyways, I'll give it a good shot today.

yeah, I wouldn't want to do this with a passenger - and it can be a challenge to find a 'safe' place, especially for a more extreme bed-in procedure.

I never heard grinding when I've done it (I have seen and smelled 'smoke' , but that was an extreme bed-in procedure), might want to inspect things before proceeding but, I suppose different brand/composition pads could behave differently from each other. I've only done this with OEM (akebono ?), Wagner, Centric PQ Ceramic and StopTech SP pads.
 

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Didn't do the bedding in procedure. I got the pads, silverline and rotors from Autozone. Can't remember where I got the parts in the past.
There's your problem. AutoZone rotors are not manufactured to proper spec. They shortcut to save production cost. Poor heat transfer, rapid warping and this leads to excessive pad wear. Their pads are poor also.

Also, every rotor right out of the box needs to have the runnout checked. Majority of the time I turn rotors out of the box to correct issues with packing/shipping/handling/storage.

The only rotors I have not had to do this with are Zimmerman, Balo and some Brembo.
 

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I started to do this and I was sensing some improvement, but I was making my passenger seasick, so I stopped. Today, I'm going out alone, so I'll do it but good! As I was doing this, I could hear some grinding on the front right brake. I'm guessing this was the start of the cleaning up??? Anyways, I'll give it a good shot today.
..if you have to "clean anything up" your sliders aren't releaseing the pressure applied to the pads..
 

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There's your problem. AutoZone rotors are not manufactured to proper spec. They shortcut to save production cost. Poor heat transfer, rapid warping and this leads to excessive pad wear. Their pads are poor also.

Also, every rotor right out of the box needs to have the runnout checked. Majority of the time I turn rotors out of the box to correct issues with packing/shipping/handling/storage.

The only rotors I have not had to do this with are Zimmerman, Balo and some Brembo.
disappointing to read - but good info.

also, shouldn't new rotors be cleaned/degreased?
 

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Discussion Starter #17
Well... it looks like I need to buy better rotors and pads..... Phooey. I did the break in procedure and I got zero improvement. I did smell brakes. I could also feel accentuated pulsing while I was doing this, or maybe I was in tune to feel for it better. Afterwards, the car is still the same.
 

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there have been instances reported where a flake of rust or other debris prevented a rotor from seating flat against the hub. But, I can't see where that would 'develop' after some period of time after brake work.

you might try Centric premium rotors and centric posiquiet ceramic pads. Or one of the brands cardoc mentioned, he has a lot of experience. Hopefully, the next change-out will do the trick!
 

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Discussion Starter #19
Folks, I finally bit the bullet and re did the front brakes. I call the store where I bought the parts originally, and there's no warranty allowed after this time frame, however, they ordered the parts on a corporate account, and the discount was equivalent to a refund. I ended up with Wagner rotors and Wagner ceramic pads. Recently, I've replaced all four rotors and calipers and pads. While I was at it, I checked the rear brakes, greased the slide pins all around and put ceramic pads on the rear also. Seems like the warping is gone now, but time will tell. I am figuring ceramic pads vs OER will help in the heat dissipation.

Thought I'd share that with you.
 

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Not warped, Judder

I've said it before and I'll say it again, many times when folks think they have warped rotors they are actually experiencing brake judder. See this link for details: -Warped- Brake Disc and Other Myths

Or read this: View attachment tech_01_judder.pdf

There is a lot of time and money needlessly spent on brake jobs when the problem can sometimes be due merely to not bedding the pads correctly or DTV.
 
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