Buzzing front brake

[(RIP) Jamie]

OK, here's the problem.

Intermittantly, during slow braking, i.e. when turning into a side road, my brakes buzz, ever so slightly, and occasionally, it feels as if the ABS is engaging, in that there's a slight pulsing coming through the brake lever.

However, hooning down the (empty) dual carraigeway, and grabbing a handful only, everything seems hunky dory, no juddering, and the bike stops OK, yet, when slowiong down for the roundabout, the buzzing comes back.

This is what I've done:

1. changed the wave washers on both discs.

2. checked both discs for warpage, none found

3. I've recently fitted new pads, and cleaned the calipers, as I usually do (they're supplied by Steptoe) they're fine, the bike stops well.

4. Did above riding tests with ABS off, some buzzing, but no pulsing

I was wondering though, when I bled the brakes after replacing the fluids, could I have bled them so "tight" that the merest pressure activates the ABS?

Sounds a bit far fetched to me.

Have I missed anything? The bike is fine and everything seems OK, in fact, part of my test run was over the Cat and Fiddle, and I had no worries regarding handling or stopping.

I even buzzed up a gravel road for a bit - no issues.

All suggestions gratefully recieved.

 

[ELIMINATOR]

All suggestions gratefully recieved.

I before E, except after C

 

[(RIP) Jamie]

I before E, except after C

I did that deliberately, to flush out all the knobbers, get them out the way

 

[ELIMINATOR]

Ta-da

I wouldn't have thought that you could "overbleed" them.

Could it be either the head bearings, or the telever bits and pieces being knackered? Just a suggestion, no practical experience.

 

[(RIP) Jamie]

Ta-da

I wouldn't have thought that you could "overbleed" them.

Could it be either the head bearings, or the telever bits and pieces being knackered? Just a suggestion, no practical experience.

I wouldnt have thought so. Over the Cat and Fiddle it was like it was on rails, I was braking into corners, maybe overdoing it, and it was fine. If it was any of the above, it would affect handling surely?

The juddering/pulsing is just coming through the brake lever, not the frame, IYKWIM.

 

[John Armstrong]

Caliper pins worn. Heavy braking takes out all the play, gentle lets it move around. Never knowingly had the problem, just an idea

 

[gpsonaPan]

Ocassionally I get something like this after I change brake pads.(I think).
Some pad materials are thinner than others ( I have been told) even from the same manufacturer.This may cause "Fluttering" of pads on sliders in calipers.

To cure this I usually slap some copper grease on back of pads (between pads and pistons) this works for me.

Hope that helps.

Pat

 

[Dahoum]

All suggestions gratefully recieved.

have you checked for a wasps nest in your calipers?

 

[Fanum]

Does sound like ABS triggering....but that wouldn't be down to the bleeding.

More likely to be the sensor rings or pickup.......recheck those and make sure there's no play, it's all lined up properly and there's no play in anything...if applying the brakes moves the ring off the sensor by a small amount, the point where the sensor trigges the abs might well be a lot further from the actual lock-up point than before





Erm.....actually, I think all that's bollix..if the ABS was triggering, you'd notice because it feels like the brakes are letting go........

I don't think it's the ABS Jamie.

Hope that helps

 

[ELIMINATOR]

And Fanum, your reason for deleting your post will be?????????????????

 

[davegs]

Polly.

She may be, but I would.
dave ( disgusting )GS. (sorry scully, your still no.1.)
"the truth is out there".

 

[(RIP) Kaister]

sounds like one of the discs has worn unevenly.

that'll give you a bit of juddering an possible ABS pulses as it trys to lock and lets go.

swap your discs for some others, one at a time.

another thing - it could be is a oily patch on the disc caused by brake fluid dripping on it - clean them with brake cleaner first ( this happend to my bike - fr m/c leaked and dripped onto it )

 

[guzzimag]

Sounds like a warped disc old chap. I subject braking components to the Guzzi flotation test. Throw them in a bucket of water, if they sink, replace them