[badbird]

2001 GL1800. When I come to a stop, the bike pulses like I am pumping the brakes lightly. Doesn't matter if I use front, rear, or both. Happens from about 20 mph to stop. Brake pedal and lever do not pulse, just the whole bike. It is too slow to be a warped rotor. Any ideas what might be causing it?

 

[PastoT]

Known issue not normally found to be a rotor problem, certainly time to flush and bleed your brake system. My 02 has done it on occasion, usually on hot days and at least (in City) speeds. I use the Rocky bleed and it remedies it for me, but it's not 100% successful for all.

Rocky Bleed
Make sure you followed all of these instructions:
BRAKE BLEEDING SEQUENCE

1: Front Right Brake Upper Bleeder Valve
2: Front Left Brake Middle/lower Bleeder Valve

Rear Reservoir (under right side chrome engine cover)
1: Front Left Brake Upper Bleeder Valve
2: Front Right Brake Lower Bleeder Valve
3: Rear Brake Lower Bleeder Valve
4: Anti-Dive: bleeder valve on top
5: Rear Brake Upper Bleeder Valve
Do these two additional Steps to be sure you have no residual air bubble in the rear system!!
6: Pressure bleeding the lower Junction block. (Upper left side of frame sitting on bike).Follow rubber hose from Secondary master cyl to the Junction block.
7) Pressure Bleed the top Banjo bolt on the Secondary Master Cyl. (To be sure the air bubble is completely out)

There are more articles search for "brake shutter".

Sent from my Moto Z (2) using Tapatalk

 

[GoldWingrGreg]

It's probably either a tire, wheel, or a warped rotor. All are easy to check for. To check for a warped rotor, get the tire off the ground and spin the tire. Usually you'll be able to hear the warped rotor when listening to the brake drag.

For the tire/wheel, as the tire is spinning look between the horizon and the tire as the tire spins. In your case the horizon is probably the garage floor. Look for signs of irregularity in the tires surface. While the tire is spinning, keep your focus on the interaction between the horizon and the tire surface. Then do the same for both sides of the tire. A tire will always take the shape of the wheel.

 

[Fred H.]

It may simply be brake material build up on one of the rotors. Try cleaning all three rotors and see if it improves. If you have a BRM type brake rotor brush then use that on a drill at medium speed on the surfaces of the rotors. You'll have to remove the front rotors to do both sides, and the rear wheel to get the rear one.

 

[badbird]

Air in system seems likely to me. Thanks for advice. Way too slow to be wheel, tire, or rotor. Several revolutions for each pulse, and it is not felt in controls. Has been doing it for a long time. Will bleed when I get some time.

 

[Pigeon Roost]

There are the two different symptoms. One is the hot weather, a rapid inconsistent shudder you feel and hear at slow speeds due to air in the front brake line from the rear brake system. A brake bleed with the Rocky steps will do wonders. The other is a true brake pulse consistently cool or hot while just coming to a stop. Bend or contaminated rotor as others noted, or in my personal experience having a Honda brand OE type rotor on wrong side of bike. I have no idea why it matters, but putting mine back where the directional arrows denote cured the pulse.

prs