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E90 brake pad squeal, what lubricant to use?

7017 Views 15 Replies 7 Participants Last post by  fun2drive
Holla,

My brake pads started squeaking a few months ago. So I took them apart, cleaned and greased the following:

1. Caliper guide pins: Greased with silver anti seize
2. Brake pad caliper carrier/braket: Cleaned and greased with the purple brake pad grease from Advanced Auto Parts
3. Brake pad ears and back: Cleaned and greased with the purple brake pad grease from Advanced Auto Parts

Now my brakes have started squealing again. I might have to grease the brake pads again, therefore what is the best lubricant to use on brake pads and caliper carrier?
Can I use silver anti seize? Or should I use copper anti seize? :dunno::dunno::dunno:
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Did you put anti squeal compound on the back of the pads?

What pad compound are you using? Ceramics are known to squeal a bit, especially when cold as do most track/race oriented pads until they are up to temp.

Do you ride your brakes often? You might have glazed them over.
Yes I did put it on back of the pads, bascially anywhere there might be metal to metal contact

I'm using Permatex Ceramic Extreme Brake Parts Lubricant from Advanced Auto Parts (purple in color)
My squeal is really loud and it happens at slow speed, so I dont' suspect the ceramics itself. However, I'm gonna take the brakes apart this weekend so I'll find out.

They might be glazed, I did ride my car for a few meters with brake pressed to get rid of the glazing, but it did not solve the problem.

So I suspect it might be the lubricat, therefore I'd like to know what you and other have had success with?
Squeal is associated with harmonic vibration. The anti-squeal compound should help. Do the pads fit loose? Did any lubricant get onto the pads which can also make them squeal?
The pads fit snug, I've checked that. The lubricant wouldn't have gotten on the pads since I did not apply a whole lot. I guess I'll find out this weekend how're the brakes looking. What brake parts lubricant did you use?
I haven't actually done a brake job on this car, but was going by past experience. Recently did my daughter-in-law's brakes using Brembo ceramic pads. Impressive kit, which included a good-sized tube of high temp lithium grease. Also have a tube of Raybestos grease in the garage which is a moly-based grease. Have never had any issues with frozen brakes parts using any of these products, nor have I considered any squealing to be an issue with brake part lubricants. The brakes on my car are mostly quiet with the exception of backing up with cold brakes which produces a not too obnoxious squeal. No noise once warmed up. Have a feeling your situation is still a high frequency harmonic vibration between the rotors and pads.
The pads fit snug, I've checked that. The lubricant wouldn't have gotten on the pads since I did not apply a whole lot. I guess I'll find out this weekend how're the brakes looking. What brake parts lubricant did you use?
Anti squeal compound is not really the same as a lubricant to me. I always use the orange stuff and let it take a bit of a set before installing. Very different than any kind of lubricating grease you would use for the caliper pins
Thanks for teh details. My brakes do a VERY obnoxious sounds for the first 2 minutes of driving in the morning (backing up and then driving), then it goes away. So, if my case is not an issue of lubrication, but of high frequency harmonics, what would be the causing it? Loose fitting pads? More importantly, what would be the solution?
I haven't actually done a brake job on this car, but was going by past experience. Recently did my daughter-in-law's brakes using Brembo ceramic pads. Impressive kit, which included a good-sized tube of high temp lithium grease. Also have a tube of Raybestos grease in the garage which is a moly-based grease. Have never had any issues with frozen brakes parts using any of these products, nor have I considered any squealing to be an issue with brake part lubricants. The brakes on my car are mostly quiet with the exception of backing up with cold brakes which produces a not too obnoxious squeal. No noise once warmed up. Have a feeling your situation is still a high frequency harmonic vibration between the rotors and pads.
Damn, never even thought about that as a potential problem, will look for that when I open up my brakes.
Most pads use spring tension or clips to hold them tightly in the calipers, and many kits also include the cushioning goo to spread on the rear of the pads for even more stability. If you have all of that in place, my guess would be either contaminated pad material or some substance used in the pad material that creates the right condition for harmonics with the rotor. Did any lube or vibration goo get onto the rotors or pads at any time? You could change the pads to a different brand and/or material and see if that stops it. I think you said you used ceramic pads, but just how much ceramic material is used in pads varies between brands. Some are as little as 5%. What else are they packing into the pad material? Have usually had good luck with Akebono Euro Ceramics. Like I mentioned above, but very impressed with the Brembo and Delco ceramics I've used in the past.

The Europeans tend to laugh at us Americans when it comes to brakes. They say that we would rather have a car that was quiet and didn't stop vs. a car that makes a little noise but stops well. ;)
Thanks for teh details. My brakes do a VERY obnoxious sounds for the first 2 minutes of driving in the morning (backing up and then driving), then it goes away. So, if my case is not an issue of lubrication, but of high frequency harmonics, what would be the causing it? Loose fitting pads? More importantly, what would be the solution?
Thanks for the info. Update on my pads is that they no longer make really obnoxious sounds in the morning, but do make a griding and screeching sound infrequently.
1. Pad contamination: I'm going to inspect my pads to determine if they are contaminated or not
2. I do have the anti rattle clips on, so I don't think its the loose fitting pads causing it
3. I will examine the handbrakes as CALWATERBOY DUE mentnioned
4. After reexamining the pads and maybe re lubricating them with the "Anti-Squeal Brake Pad Paste" you mentioned, they still squeal, it must mean that the pads themselves are causing squealing.
Most pads use spring tension or clips to hold them tightly in the calipers, and many kits also include the cushioning goo to spread on the rear of the pads for even more stability.....................
The Europeans tend to laugh at us Americans when it comes to brakes. They say that we would rather have a car that was quiet and didn't stop vs. a car that makes a little noise but stops well. ;)
When nothing else works chamfering the pads does help.
I have done this with some sets of pads that would squeal even with brake pad vibration goo and everything else perfect.
Chamfer as in grind to a smoothness? What equipment did you use?
When nothing else works chamfering the pads does help.
I have done this with some sets of pads that would squeal even with brake pad vibration goo and everything else perfect.
No you chamfer to put an angle like 45 degrees on the edge of the pad that contacts the rotor. A file does a fine job so does a dremel tool. Pretty common when all else fails.
Surprised the brake vibration goo is not working as it usually soaks up the vibrations caused by the rotor to pad contact...
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