Help with brake?

[Ricco1]

My 1982 RS125DX (disk) front brake works, but isn't as effective as I'd like it to be. It doesn't feel particularly spongy but just doesn't have the stopping power it should have. The pads appear to be within the wear tolerance. I've checked the hydraulic system there are no obvious leaks.

I was thinking of doing the following:

1/ Try spraying some brake cleaner on the pads. There was an oil leak from the fork that holds the caliper. This was fixed 6 months ago but maybe it's possible the pads hold some residual oil?

2/ Replace the hydraulic fluid. Although the lever doesn't feel spongy I don't know how long the fluid has been in, I only bought the bike last year.

Is this the right approach, or any other ideas?

Cheers.

[megawatt]

Replace pads, try it, then replace fluid.

[fastbob]

Pump out the pistons , remove seals , carefully scrape out the crap from the grooves , reassemble, fill , bleed . You'll be astonished at the difference this can make .

[Fleck]

Replace pads, try it, then replace fluid.

+1

[Ricco1]

I took the caliper off then the pads, for a closer look. They are virtually new, within a mm of the new size. They are also in good condition, no oil or other contaminants on them. I'm going to have a go at pumping the old fluid out and replace with new. It's just a single front brake, the rear is a drum, would a 250ml bottle be enough of should I get 500ml? The manual doesn't state the capacity..

[TimR]

Have you measured the Disk thickness and is it within tolerances ?

As it had a oil leak i would replace pads

Could also be

Fluid deteriorated

Brake hose weak/ collapsing

Caliper sliders seized/poor operation

Caliper pistons seized/ poor operation

[fastbob]

I took the caliper off then the pads, for a closer look. They are virtually new, within a mm of the new size. They are also in good condition, no oil or other contaminants on them. I'm going to have a go at pumping the old fluid out and replace with new. It's just a single front brake, the rear is a drum, would a 250ml bottle be enough of should I get 500ml? The manual doesn't state the capacity..

 

Get two 250ml bottles because it not a good idea to store an opened bottle for a long time .