Have 40k on my 09 UC, it seems the brakes are pulsating alot lately, have the HD semi floating rotors installed since new. Is it time to change them out? Anything else cause this, both front and rear brakes doing it.

 

Pulsating brakes are a good indicator of warped rotors. Anyway you could check runout with a dial indicator setup?

 

ABS?

I can remember when they began putting ABS on cars. On the repo truck I drove at the time, you could feel the brake pulse in the steering wheel...

 

Pulsating rotors are a sign the rotors are warped (no different than your car). The cause is usually due to the pistons getting dirty and not retracting fully when released. Having one or more of the pistons sticking causes the pads to wear uneven and exacerbates the problem. If you see the pads wearing uneven, this is your first clue about the sticking pistons. The heat caused by dragging pads causes the warpage and also cooks the brake fluid. I do piston cleaning every 10K and re grease the pistons with silicone grease if needed.

 

Warped rotor because they don't pulse normally. Something else that can cause it? Ya, some jealous wimp kicking it or dishonest tire change because someone bent it.

 

before running out to buy rotors, clean the rotors with brake clean first. Somtimes dirty rotors make the lever pulsate like a warped rotor.

 

"dishonest tire change". I put a new set of tires on at the stealership and while riding out of the parking lot....pulsating from front brake. Turned it right around and had them replace it.

 

I appreciate that this is a "thread from the dead" but can anyone clarify what a "dishonest tire change" is and how tire condition might cause and effect pulsating brakes.

Yes, I am also diagnosing a pulsating front brake on a Road King with fully floating disks.

Thanks

 

Warped rotors. Replace with pads. Nothing to do with ABS. Good excuse to get some sweet lookin rotors

 

Try new pads, cleaning not just the rotor but the brake pistons as well. When brake dust builds up on the brake pistons the pistons do not retract completely into the bore of teh caliper. It is not only heat from dragging pads that cause warp[age but the heat created by the Brembo calipers. They create much more heat than the older style calipers.

http://www.lyndallbrakes.com/service-tech/