Strange noise

[Greybeard]

I could swear I posted this before but can't find it again.

 

Last year I pulled up to a stop and heard a soft "woo-woo-woo" noise from the rear and I thought I was told it was the rear brake...but I can't remember the fix!

 

Anyone care to re-educate me? Caliper rebuild was it?

[raz]

They don't sell caliper rebuild kits anymore.

 

I get that sound now and then (not often) despite nothing's really wrong. When it happens, check the rotor for heat. If you can keep your hand on it without getting hurt, there's no problem, unless you really want to get rid of the noise anyway.

 

Check the pedal play. There must be 5-10 of mm of play before the rod touches the master cylinder inside that rubber boot.

 

Also, remove the pads, inspect them and the rubbers, clean everything and put together again.

[Dan M]

 

Also, remove the pads, inspect them and the rubbers, clean everything and put together again.

 

A good clean up always works for me

[Guzzirider]

 

 

heard a soft "woo-woo-woo" noise

 

Ratchet's ghost tapping on the window begging to be let back in again?

[helicopterjim R.I.P.]

Ratchet's ghost tapping on the window begging to be let back in again?

 

That is very funny! Thanks!

[Greg Field]

That is very funny! Thanks!

 

 

Yes. Just stick a fork in this site. It's done.

[The Monkey]

In addition to the clean up, It helps to put the pistons in the caliper through the operating range of motion while replacing the fluid in the system. Pop the caliper off, put a spacer between the pads so the pistons dont come free of the housing (I use a combo wrench laid in between) pump master to shove pads out, open bleeder and twist spacer to push pads back in all the way. Repeat till you've exchanged all the fluid. Due to the fact the bleeder is on the bottom of the caliper when mounted on the bike it is easier to final bleed any air out with the caliper off too (bleeder up). This exercise helped the pistons retract far enough on my bike when the brake pedal was released to get rid of that howl from the stern. As the sound is vibration induced it may help to put a little extra anti sieze on the caliper arm locater/slider as that seems (to me) to have excessive tolerance and may well contribute to the racket. Hope this helps, Cheers

[raz]

Aye. Good write up. Dang, I should do this myself.

 

While on the subject, does anyone have an opinion on brake line hoses? My bike is a 1997, likely with brake lines never replaced. They look fine. Should I just continue to replace fluid now and then or should they be replaced after this or that age?

[gstallons]

The fluid is hygroscopic (attracts and accepts) moisture. Use DOT 4 fluid. The hoses should be fine as long as the exterior looks good. If you do not have braided steel lines and don't mind the $ get them.

[Greg Field]

You clearly are blinded by groupthink and haven't yet bloviated your obfuscator adequately. What are you you, some sort of Commie agitator?

[Admin Jaap]

You clearly are blinded by groupthink and haven't yet bloviated your obfuscator adequately. What are you you, some sort of Commie agitator?

 

Huh? Are you being sarcastic? It's hard for a not-native speaker to understand

[ponti_33609]

This was posted years back over on the MGNOC site. Not sure if this is what you are experiencing?

 

Premature Rear Brake Wear on V11 Sport and Others

Seatmaster Rich Maund describes a problem he found on his V11 Sport, and the solution:

 

I have read a number of letters in different places about premature rear brake wear on the V11 Sport type bikes. Mine has always had a slight "wup.....wup" sound at slow parking lot speeds. But the rotor wasn't warped and the brake functioned well enough. Not strong, but okay. No signs of overheating and melting anything either. So I never gave it any more thought.

 

Last week with 8000 miles on the bike I tore into it for some preventive maintenance. I flushed all the hydraulic systems and tore down the rear drive to grease everything. Actually a much easier job here than on a Tonti framed bike. I found one rear wheel bearing felt notchy. That was depressing, but I was happy to have found it before it completely failed. The local bearing shop sold me two bearings the next morning for under $17 to replace them. Smooth as silk now. The real surprise was finding the rear brake pads worn to under 1/16 inch thickness! Here's how I believe the problem came about: The rear caliper mounts upside down. So the vent for it is on the bottom. Air bubbles float up right? When I bled it, I did so by removing it and placing it upright to get a good bleed on it. I did find some air trapped in it. Any chance the factory bled the system with the caliper installed so that the vent was on the bottom when they vented it? I think so. Sheesh! If air was trapped in the caliper, it would be warmed by the hot brake pads/pucks and expand as I rode the bike, thus making the brake drag a bit. Remember I mentioned mine made a "whup whup" sound at low speeds?

 

Apparently it was dragging a bit ALL the time. I just couldn't hear or feel it. I did check to see that the pucks moved inward smoothly as I pumped up the rear brake. No problems there. No binding. After re-assembly the unit worked very smoothly. NO dragging and no more noises. May be my imagination, but the rear brake has better feel and power to it as well. 100 miles now and it continues to work quietly. No more dragging noises. I believe the air in the caliper was the problem.

 

It's very simple to remove, flip right side up and bleed the rear brakes on these bikes. I recommend you try that if you have noises similar to what I have experienced. It could get really expensive if you wear the brakes down to bare metal.

[Skeeve]

Here's how I believe the problem came about: The rear caliper mounts upside down. So the vent for it is on the bottom. Air bubbles float up right? When I bled it, I did so by removing it and placing it upright to get a good bleed on it. I did find some air trapped in it. Any chance the factory bled the system with the caliper installed so that the vent was on the bottom when they vented it?

 

Actually, having the brake mounted upside down like that would be beneficial if modern manufacturing processes are used and the brake fluid is forcibly introduced from the bleeder and old fluid removed at the brake reservoir. That's the process that Harley-Davidson adopted after observations made when taking a tour of the various J-4 plants prior to their turn-around in the 80s. Up til then, they'd always had difficulties getting their front brakes properly bled in production.