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[dgsmith]

OK guys,
I have owned 6 or 7 motorcycles over the years but this my first harley.  I picked up my bike from storage at the harley dealer and I had them change all the fluids since I bought the bike used. They flushed the brake lines and now I hear the brakes slightly rubbing on the rotors. I have never hear this on any bike I have ever owned. 2 harley dealers said this is normal with harley brakes. Is this right? the rubbing sound drives me nuts. When you brake it goes away. You can hear it rub even when you push the bike in the garage. It is a 2003 SE road king.

[grc]

OK guys,
I have owned 6 or 7 motorcycles over the years but this my first harley.  I picked up my bike from storage at the harley dealer and I had them change all the fluids since I bought the bike used. They flushed the brake lines and now I hear the brakes slightly rubbing on the rotors. I have never hear this on any bike I have ever owned. 2 harley dealers said this is normal with harley brakes. Is this right? the rubbing sound drives me nuts. When you brake it goes away. You can hear it rub even when you push the bike in the garage. It is a 2003 SE road king.

The old Harley calipers don't have secondary piston seals to keep crud and brake dust out, so it's not uncommon for the pistons to stick rather than retract slightly when you release the brake lever.  This will cause the pads to rub.

You can often fix this by removing the caliper and pads, and then cleaning around the pistons.  Carefully extend the pistons slightly by gently applying the brake (put a thin block of wood or other material between the pistons to keep them from popping out), then use brake cleaner spray to flush the crud from around the pistons in the caliper bores.  When you have cleaned all the pistons, press them back into the caliper and then gently apply the brake while watching the pistons.  They should all extend the same amount and at roughly the same speed.  Continue to extend, clean, and press the pistons back in until they all extend smoothly and require about the same force to press back in.  Reinstall the pads, reinstall the caliper(s), apply the brake lever or pedal to extend the pads out to the rotors, and take it for a test ride.

This is something that needs to be done probably once a year on the bikes with the earlier (non Brembo) calipers. 


Jerry

[marshall10]

good disc brakes will always have a little friction when they are disengaged, it's part of the technology that helps us stop. The closer the pad to the rotor the more consistent it is and the quicker it works(less travel) also the less fluid you need and therefore less compression of said fluids and less flexing of lines. They should have a little "metal scraping against concrete" sound. If it is too much, or the bike rapidly decelerates after pulling in the clutch I would check the calipers and possibly remove them, bleed some fluid, and compress the pistons to get the pads at a more acceptable position. Brakes are possibly the most important system on ANY motorcycle. If you are unsure of what you are doing PLEASE, PLEASE, just for me, pay someone else to do it that is competent.

[greglyon]

I've got the same bike and have the same issue.  The sound comes and goes.  I have gotten used to it over the years.  The more significant problem is the 'squishiness' of the front brake.  A lot of travel between depressing the lever and engagement of the brake.  Have had it in several times, they fix it and in a 6-10 week period the problem comes back. 

[skreminegul07]

If the sound is not steady, it could be a warped rotor.  It will hit once every revolution of the wheel.  Jack up the bike and then turn the wheels by hand.  If the drag is even, then the cleaning process is needed.  If if you can feel the drag and only one part of the rotation, its a warped rotor and replaced in the fix.  A warped rotor will pulsate the brake lever /pedal on hard braking, also.
If you have the HD squeal, go to Lyndall pads (lower dust) and also floating rotors.  I gave up the battle and went all floating and squeks stopped.

[dgsmith]

Would different calipers like performence machine 4 or 6 piston work better. Would you still get the rub ?

[marshall10]

Would different calipers like performence machine 4 or 6 piston work better. Would you still get the rub ?

you would still get a "little" rub(more of a sound as described before) but performance machine or brembo, or several others will be better performance brakes. also a lot of after market rotors stop better and are also lighter.

[grc]

Would different calipers like performence machine 4 or 6 piston work better. Would you still get the rub ?

While it's true that you don't want the pads to be actually retracted like the old shoe type brakes, you also don't want them to constantly rub either.  In normal operation, the piston seals don't slide with each brake application, they tend to deform slightly as pressure is applied and the piston moves.  When the pressure is relieved, the seal returns to it's normal shape and slightly retracts the piston. We're talking about movement in the ten-thousandths of an inch range, not much but just enough to relieve the pressure on the pads.  In the case of the older style multiple piston Harley calipers, there is no secondary seal to keep brake dust and grime out of the tiny gap between the piston and the bore.  That crud is what keeps the piston from retracting slightly as it was designed to do. 

If all you are looking to do is eliminate the constant dragging of the brake, a high priced replacement caliper is overkill.  Just add the cleaning procedure to the yearly maintenance schedule.  If you want significant braking performance improvements, then by all means look into the higher quality and higher performance replacement parts.  Be aware that this can get very pricey, especially if you upgrade both the rotors and calipers.  It's not unlike the opposite situation, modifications to make the bike faster.  "Speed costs money, how fast do you want to go?"  becomes  "Stopping fast with good control costs money, how fast do you want to stop?"  Before you start writing checks for thousands, you may want to just try the Lyndall Z pads and a good caliper cleaning.  Figure about $130 for parts (3 sets of pads) and brake cleaning spray if you do it yourself.  If you're still not satisfied, you're not out that much cash and can still go with the big bucks approach if you want.


Jerry