Brake squeal

[Athame57]

Twice in the past four weeks I've had the caliper apart to copper grease the rims of the pads backing and check the leading edge of the pads themselves are bevelled, as well as greasing the caliper interior, and there is is again,  I'm at  a loss by now. Ideas anyone, apart from oiling the disc that is. 

[Johnwebley]

Put up with it for a while

But use the front brake hard!

Some times I think the disc needs a firm polish

Hopefully after a few rides it will be quieter

Sent from my SM-A546E using Tapatalk

[McCabe-Thiele (Ted)]

Might be worth thoroughly cleaning the pads and disc surfaces if you have not already done so.
Whose pads have you fitted?

[Bryanj]

I think that basically you end up living with it, since asbestos pads were banned it seems to have become a more common thing. Things suggested on both here and the US forum are, in no particular order of possibility,

Make/material of pads
Paint on outer of moving pad
Nylon ring between pad and piston
Freedom of pivot pin in caliper bracket
Crud behing caliper seal
Blocked return hole in master
Collapsing flexible brake lines
Clearance of fixed pad to disc, allong with spring
Disc surface itself contaminated, occasionally scrubbing with scotchbrite pad and brake cleaner MAY help
Play in wheel bearings

I have read posts where people swear that one or more of these will cure the problem but personally i have my doubts, i like to think of it as an alternative audible watning of approach!!!

There is also now appearing an idea that coppaslip is not the best thing, i do not adhere to that idea!

[exvalvesetdabbler]

The pads are glazed.

Put some medium grit sandpaper on a flat surface, rub each pad on that until the shine has been removed.

When you reassemble,make sure that the pads aren't dragging on the disk.  That seems to glaze the pads more quicky.

Seems to happen to me more often using modern pads

Regards
Dave

[Athame57]

The pads are glazed.

Put some medium grit sandpaper on a flat surface, rub each pad on that until the shine has been removed.

When you reassemble,make sure that the pads aren't dragging on the disk.  That seems to glaze the pads more quicky.

Seems to happen to me more often using modern pads

Regards
Dave

I think ( know ) I'll take that approach tomorrow and pray it works.  Some people think I'm being cruel to my bike!   

[Athame57]

Whose pads have you fitted?

Hi Ted
I'm not sure of the make , but they have always come from DSS.

[exvalvesetdabbler]

The ones that I have are EBC and they still start to squeak a little after about 500ml   Previous ones were from DSS bought in the mid 90s squealed like a stuck pig.

I have the nylon ring still in there, makes no difference, just makes the braking effect a little more progressive.   What makes a difference is cleaning out all the corrosion in the groove that the seal occupies, not just gunk or bits of old seal, the corroded aluminum crust.  Failure to keep this groove clean makes the piston tight and it doesn't retract properly or enough.  With the front wheel off the ground it should spin easily with one finger with minimal rubbing sound of the pad on the disc.


Regards
Dave

[Athame57]

The ones that I have are EBC and they still start to squeak a little after about 500ml   Previous ones were from DSS bought in the mid 90s squealed like a stuck pig.

Hhhmmm...remember the look on peoples faces in the scene in the film JAWS where Quint dragged his finger nails down the blackboard? 
That's what people on the street around me look like sometimes when I brake! 

[florence]

For the last thirty years, mine has always squealed, different pads, various things, rubbed with emery, blah blah, always the same.  I am used to it, and feel comforted that something is happening down there.

I do not think it can be eliminated, just one of the many quirks. 

[Johnny4428]

I’ve always had an issue with the 550K3 but never had a squeak out of the K1. Would need to compare and see where I bought pads for K1. Incidentally was a new Caliper fitted to K3 when restored.

[McCabe-Thiele (Ted)]

Anecdotally I think there are many factors involved, I have found in the past that hard pads are worse than soft ones for making a noise.