Topic: Squeaky front brakes!!!!

[guitarkev66]

Okay I've read all of the FAQ's about squeaky breaks anyone have any other fixes.  Here is what I have a 1970 cb750, cleaned front caliper, new piston seal, new brake pads (OEM honda bought from honda honda picking number on the bag), master cylinder rebuild kit from honda.  Also sanded glazing off rotor.  Breaks work great but squeal like a pig.  The pads already have a 45 degree chamfer on them.  Any ideas? Brakes squealed before I replaced all the parts.  The piston was very clean and slid right into the caliper with minimal effort. I made sure to clean the ridge that the rubber seal sets into.

[dhall57]

I wish I had the fix. I've done the same to both my KO and K6 that you've done Kev. Brakes work fine, but still have some squealing. I've for the most part have just learned to live with it.

[BobbyR]

I and others have battled this for years. I bought some new Ferodo pads. All I can say is that they are better, but they squeak now and then.

[Brantley]

I've never had OE Honda pads squeal. Not badly, anyway. Maybe I'm used to it... I'm gonna guess you have the caliper adjusted. Try braking lightly the first 50-100 miles (maybe use the rear brake more than you're accustomed to). After that practice your emergency braking technique as often as is safe for a while (I can't give you a mileage or time frame not knowing your riding habits; maybe a week if it's your daily?). That "fresh"noise has gone away pretty quickly for me using this method...

[shinyribs]

New pads(of any brand) tend to squeal at first. I used some CRC disc break quiet on my mine and just did what the can said to do.Helped-but not a 100% cure. I have Honda pads,too.Helped some more-still not 100% Mine used to squeal and I cannot stand that sound. If I rough my rotor up with 80 grit it does fine.I usually have to re-scuff every 300-500 miles depending on how hard I've been riding. Honda pads,correct dead pad adjustment,CRC disc break quiet and regular scuffing. I've had silent-not quiet or tolerable-SILENT brakes for the past 5,000 miles doing this.So long as I stay on top if things If you find the scuff doesnt work when they begin to squeal again,its time to adjust the dead pad. I've only had to adjust mine once,about 3,000 miles on new pads when needed readjusting.

Sounds like alot of work,but its worth the regular scuffing to keep it quiet-for me at least.

Good luck with it-I feel your pain

[Fritz]

Squeeling brakes are as annoying as the effords required to fix them.

Here's my checklist:

- Master cylinder - make sure the tiny "return hole" at the bottom of the reservoir is clean

- Brake line - must be unclogged and without air trapped inside

- Calipers - must be clean as hell - especially the groove the piston seal sits in. Requires new seal and brake fluid whenever taken apart

- Pads - originals are the best - at least a good starting point if you try to fix squeeling brakes. Make sure you've got that nylon washer behind the moving pad and seal the piston with "brake grease" (e.g. Down Corning Molykote products)
Aftermarkt pads may require sanding and polishing the side faces to prevent binding inside the caliper bore

- Caliper arm - must be parallel to the brake disk. Misaligned arms cause the pads to tilt

- Caliper arm pivot bold - If it's worn, the arm moves vertically which may cause squeel. Disassemble, clean and grease that bolt. If worn badly, the arm may require a bushing reamed to the size of the bolt

- Disk - Deglaze and make sure it's true.

[trueblue]

I must be lucky, my 650 front brake only squeals when dead cold and I apply the brakes really light.  At all other times they are silent.  I have shiny rotors, aftermarket pads and I just fitted them with a very light smear of coppercoat on the points that Honda says to grease.

[bollingball]

I must be lucky, my 650 front brake only squeals when dead cold and I apply the brakes really light.  At all other times they are silent.  I have shiny rotors, aftermarket pads and I just fitted them with a very light smear of coppercoat on the points that Honda says to grease.

Same here first two times in the morning then nothing the rest of the day. Even if it sits a couple of hours. I don't know why it does it only in the morning I think it is temp and moisture.

[NewOldSchool]

Copper grease or any other "anti squeak" grease from an auto parts store will work wonders.

Spread some behind both brake pads and on the piston, no more squeaks. Just don't get any on the face of the pads.

[Duke McDukiedook]

Copper grease or any other "anti squeak" grease from an auto parts store will work wonders.

Spread some behind both brake pads and on the piston, no more squeaks. Just don't get any on the face of the pads.

I disagree, these brake pads get way too hot for automotive brake grease.

[derelicte]

What type of grease, then

[Mooshie]

Wait the brakes are not supposed to squeal? Mine squeal intermittently and when I cannot stand it anymore I put some rubbing alcohol on a rag and clean the rotor (both sides).  This stops it for awhile and then reappears.  Also, the longer I ride the less squeal. I just learned to live with it and figure it is another safety feature on an otherwise perfect bike.

[shinyribs]

You can buy silicone brake grease are any auto parts store. It's non melting. Good stuff to use on the pivots in your rear drum, too.

[Bailgang]

I tried everything mentioned above on my 75 cb550 but it would only last for a day or 2 and come back. I even tried Dow Corning high vac grease which did help but it still squealed just not quite as bad. What has done the trick so far is I nabbed a rotor from a cb500 rim I had and cross drilled it. The key words are "so far" because I've only put about 150 miles on the bike since I swapped rotors over the weekend but it hasn't squealed AT ALL since I made the swap. There are a couple of variables going on, 1 is the cross drilling of the rotor and 2 is the fact the 500 rotor isn't glazed nearly as bad as the 550 rotor was so one can argue was it the cross drilling that did it or the fact that the rotor isn't glazed as bad as the other?

What I can say is that while researching the idea of cross drilling my rotors, the 1 comment that kept popping up in the threads I read was that cross drilling the rotor pretty much eliminates brake squeal for good and in my case that seems to be correct at least until I put some more miles on the bike to confirm it.

[mycb750k6]

Did you use the caliper assembly lube? Use it under the seal, behind both pucks and on top of the piston. Shouldn't squeal with the caliper lube.

[bjatwood]

I think it has to do with rotor glazing. When my K3 starts doing the kiiler CB brake squeel thing. I get my garden hose out, spray wheel cleaner on everything, let it sit for 1 minute spray it all off with the hose. Get out the 3M green scuff pad, scuff up the disc and spray it down with the hose again to wash away any sanding "grit"
Then take it out for a brisk ride and enjoy the quite!

[70CB750]

You can not fix it, it is a feature:)

[trueblue]

I disagree, these brake pads get way too hot for automotive brake grease.

This comment comes up quite regularly on here, I just can't see how pulling a 220kg bike up expends more energy and generates more heat than stopping a 2 ton car.  Think about this scenario, if you have a 2500kg 4WD towing a 3500kg caravan, you have a gross combination weight of 6 ton.  The Kinetic energy of this 4WD/caravan combo is 2,313,518.7 joules, where as the motorbike travelling at the same speed, allowing for a rider, lets say total weight is 320kg, kinetic energy is only 123,387.6 joules.  For the motorbike to be carrying the same amount of energy you would have to be traveling at 432kph.  Even if we work it out on a standard sedan weighing 2 ton traveling at 100kph it has 767,290 joules of kinetic energy, for your motorbike to produce an equivalent amount of energy you would have to be traveling at 249kph.  Remembering that kinetic energy gets turned into heat energy by your brakes, so just how is it you figure out the brakes on these bikes get hotter than those of cars, when there is simply less energy available to heat up the brakes.

[aperry]

Some people claim that cutting an "X" or "#" pattern in the surface of the pads also helps eliminate the noise. 

I put some of the Corning high temp vacuum grease behind the pads and it only helped a little bit. 

At some point I'll try the cutting method.  Maybe over the winter I'll get the rotor drilled. 

Aaron


Sent from my iPad using Tapatalk HD

[Duke McDukiedook]

What type of grease, then

Dow Corning high temperature vacuum silicone grease, info on it should be in the brake faq along with other info.

[derelicte]

I disagree, these brake pads get way too hot for automotive brake grease.

This comment comes up quite regularly on here, I just can't see how pulling a 220kg bike up expends more energy and generates more heat than stopping a 2 ton car.  Think about this scenario, if you have a 2500kg 4WD towing a 3500kg caravan, you have a gross combination weight of 6 ton.  The Kinetic energy of this 4WD/caravan combo is 2,313,518.7 joules, where as the motorbike travelling at the same speed, allowing for a rider, lets say total weight is 320kg, kinetic energy is only 123,387.6 joules.  For the motorbike to be carrying the same amount of energy you would have to be traveling at 432kph.  Even if we work it out on a standard sedan weighing 2 ton traveling at 100kph it has 767,290 joules of kinetic energy, for your motorbike to produce an equivalent amount of energy you would have to be traveling at 249kph.  Remembering that kinetic energy gets turned into heat energy by your brakes, so just how is it you figure out the brakes on these bikes get hotter than those of cars, when there is simply less energy available to heat up the brakes.

MC caliper is better ventilated too.  Maybe thicker calipers on your average car dissipate faster?  Essentially one brake versus four as well.

[shinyribs]

Some people claim that cutting an "X" or "#" pattern in the surface of the pads also helps eliminate the noise. 

I put some of the Corning high temp vacuum grease behind the pads and it only helped a little bit. 

At some point I'll try the cutting method.  Maybe over the winter I'll get the rotor drilled. 

Aaron


Sent from my iPad using Tapatalk HD

I tried the cutting and the bevelling. Did nothing.Save yout time and scuff your rotors These rotors are slippery and require quite a bit of pad force to generate enough force to stop.They are not high friction material like the late model bikes have. Lots of pad force=glazing. Glazing=squeals. DE-glazing=no squeals 

Go for a ride on a glazed,slippery rotor and grab a handful of front brake. Then repeat with a freshly scuffed rotor-big difference. No squeals and more braking power.

[trueblue]

MC caliper is better ventilated too.  Maybe thicker calipers on your average car dissipate faster?  Essentially one brake versus four as well.

Doesn't your bike have rear brakes .  Generally cars have heavy cast iron calipers and these retain a lot more heat than the lightweight alloy ones on these bikes, so in instances of driving hard they heat a lot more than alloy calipers.  There is a lot more metal there to heat up than there is on a bike, but there is also a lot more metal there to retain heat.  I don't know about you, but I have had rotors on a car to the point of brake fade during a period of hard driving.  Brake fade occurs when the braking surface heats up to the point where it no longer provides any friction because the metal under the pad turns red hot.  Brakes don't get any hotter than this, there is nothing special about the brakes on these bikes, if a grease is designed for automotive applications it will withstand anything these bikes can throw at it.   Even if you rely solely on your front brake to stop you from 100kph you are still putting less energy into your brake then what goes into each car brake.  The example I used above the car travelling at 100kph has 767,290 joules, this equates to 191,822.5 joules per brake assuming that each brake does equal work, which they don't, the front does approximately 80% of the work.  This changes with numerous variables, like weight distribution, the rate at which you stop, grip on the tyres etc etc. But in this instance lets just work on them doing equal work, this would mean that to get an equal amount of energy into your front caliper as what there is applied to just one brake on a car weighing 2 ton travelling at 100kph the bike would have to be travelling 124kph.

[crazypj]

The single disc is barely adequate for normal riding, how do you lot manage to get pads glazed over so easily?
I've had centers melt out of pads (fitted a second disc after that)
I've also had severe brake fade on one car (OPEL Manta GTE with 'warmed over' 2.3 motor)
100kph is only 62~63mph, leave braking a bit later and get things warmed up

[shinyribs]

Yeah,the single disc is weak.That is why it is so easy to glaze them. Normal riding almost overworks the brake system,thus glazing the pads.