New pads/rotors, grinding already

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I was getting some grinding when slowing to a stop on my front brakes, so I pulled the tires to check the pads. The rotors were GM OEM original to the car, and this was probably the 3rd set of pads. It had a pad-slap about 2 summers ago but only 10k miles or so since then, so I was pretty sure the pads were ok, and they were. However, since I had it all apart, I decided to go ahead and just replace the rotors and pads. $75 or so later and I had Wearever rotors and Wearever Silver pads installed. This was the first time I had done brakes by myself, and the first time Id ever done rotors. Everything went back together easy. Braking was good, smooth, quiet. This was about 2 months ago. About a month ago, I had to make somewhat of a hard brake. Since then, the front brakes are grinding again. Seems like they are getting worse. When I come to a slowing stop at a light or stop sign, both sides sound like they have rust on the rotors. I drive the car daily so its not actually rust. Could it be the cheap Silver pads causing the problem? Could it be the wheel bearings? I hear those go bad on this car often, but Ive never had a problem in 13 years that im aware of.
 
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Somethings off in regards to runout. Either the rotors are not true, or they are not sitting flat on the hub face( rust). Or the bearings are allowing movement. I have seen this happen if one forgets to tighten the caliper bolts.
 
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Mar 21, 2004
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When you recently did the pads did you lubricate the sliding pins and the area that the tab of the pad rides along? You will need to check everything to see what is going on. Caliper may need to be replaced or rebuilt. Wheel bearing and brake noises sound different and at different times.
 
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That is the kind of sound you should get right back in there and see how your initial work is doing. Could be a good cleaning of build up is needed or one of the caliper pins has stuck and has made a pad wear uneven and quickly. Did you clean and then lube the caliper pins when you did the brakes? When you get back in there, do it. Guess we can conclude this is a GM car however worn out wheel bearings have always given me clear sound alarms and enough play in the test with the wheel off the ground to conclude replacing.
 

JC1

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Originally Posted By: Donald
When you recently did the pads did you lubricate the sliding pins and the area that the tab of the pad rides along? You will need to check everything to see what is going on. Caliper may need to be replaced or rebuilt. Wheel bearing and brake noises sound different and at different times.
+2 on this. Also did you use a torque wrench on the bolts you touched? It may sound trivial to torque it, but if you do you and you lubricate everything properly you should get better results IMO. Regards, JC.
 
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Originally Posted By: JustinH
grinding or bedding in? My somewhat sporty pads took a while to stop humming while they were still bedding in. Literally 4 weeks.
I'm going with this. Our delivery car at work had it's front rotors (cheapies) replaced along with new bosch pads. It took a few weeks of driving to bed them in until the grinding noise stopped. And this is on a car that is driven nearly 8 hours a day 5 days a week.
 
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Originally Posted By: Charlie1935
If one gets in a hurry and somehow puts pads in wrong side out they start grinding pretty quick. Don't ask how I know. frown
How well does that combo stop?
 
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Go to napa and buy a tube of sil-glyde lubricate the slide pins and the ears of the pads where they sit in the clips. A small dab of blue loctite on caliper bolts for 'insurance'..but not required. Im guessing you cleaned your rotors of oil before you installed pads? if not your pads will probably have a glaze on them, just uninstall and either sandpaper or wire brush the pad faces to get the glaze off..clean rotors well and reinstall.
 
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Originally Posted By: Donald
Originally Posted By: Charlie1935
If one gets in a hurry and somehow puts pads in wrong side out they start grinding pretty quick. Don't ask how I know. frown
How well does that combo stop?
It stopped ok. Didn't go out of town, Took care of it when I got home from trucking that week.
 

FL-400S

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I think the noise is both wheels, so I doubt I forgot to tighten the calipers on both sides. I remember triple checking. I dont have a torque wrench but ill probably go get one soon. I lubed the pins and pads. Funny thing is, previous pad slaps Ive done with an "instructor", we never bothered. Never a problem. I was very careful to replace the pads exactly the same way they came off. I realize there are 4 in the box that look very similar but are all different. Yes I sprayed the rotors with brake kleen and wiped with a clean t-shirt before installing. Today on the drive home I (almost) stood on the brakes a few times from about 60 down to 20. Not enough to get ABS working. Is a lot quieter now. Ill get to harbor freight and pick up a torque wrench and get back in there this weekend to see if anything is really off.
 
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What vehicle (besides just "GM")? I had a grinding noise problem on my Dakota front disc brakes (I'm sure very different than yours, but read on). It turned out the tracks (not the pins, it has pins, too) had indents in them, a pad was stuck in the rut and was pivoting instead of sliding evenly over to the rotor. On top of that, those tracks were supposed to be lubed, but weren't. (Grrr) It's worth taking off the caliper, checking to see if all surfaces were the pad's metal backs makes contact are smooth, even and lubed. In addition, if your brakes can use abutment shims, check if all the abutment shims are present, and are smooth, lubed and rust-free. These shims are often "lost" during previous "pro" break jobs, and the resulting slop makes for uneven wear and noises. In my case, shims were needed to take up slack only on one end of each pad, if I tried to put them on the other the pad wouldn't fit. For some GM's, the shims are huge and required, but I don't know what vehicle you have. Abutment shim sets are usually 8$ at Rock Auto. In some cases they are mandatory, in others they are used to shim-up to fit only as needed.
 
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Originally Posted By: krismoriah72
Go to napa and buy a tube of sil-glyde lubricate the slide pins and the ears of the pads where they sit in the clips. A small dab of blue loctite on caliper bolts for 'insurance'..but not required. Im guessing you cleaned your rotors of oil before you installed pads? if not your pads will probably have a glaze on them, just uninstall and either sandpaper or wire brush the pad faces to get the glaze off..clean rotors well and reinstall.
This was what I was thinking as well. +1 The brakes seem too new to be causing that sound just yet. Sounds to me like it needs to get greased up and it should be good. Did you replace the hardware too? Might be worth ordering the kit to replace the hardware as well.
 

FL-400S

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Well I had it all apart yesterday and everything looked fine on both sides. All bolts were tight, there didnt seem to be any uneven wear, there never was any pulsing. I think it is just noisy pads or rotors. They only have about 4000 highway miles on them. I went ahead and replaced the pads and hardware with wearever platinum after wire brushing and blowing a lot of brake dust out of the calipers. Greased everything as appropriate, torqued everything with my shiny new harbor freight torque wrench. Checked afterwards with ratchet to make sure everything snug. It seems better. I think its the rotors, which still have the factory machining on them. I'm going to drive it and give it some time. Username comes from the use of this filter on toyotas.
 
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Originally Posted By: ted s
those cheap brake parts from advance are junk
I've used wearever products several times from advance auto and have had no issues. are you talking about brake components in general or hardware kits etc?
 
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^^^Wildly platform specific. Everyone here seems to think that all brake pads of one name brand contain the same friction material when that is rarely the case. I have had good and bad parts from many suppliers in my fleet. OP, it sounds to me like you've been too easy on those pads and rotors. Use them a bit, and wear them in properly. I bet they will eventually be fine...
 
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Wearing in properly means hard near-stops, but don't let the wheels stop turning or they'll deposit friction material in one spot which leads to uneven braking (that "warped feeling").
 
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