Hope Tech M4 Brake - Manual (Page 9)

9
3.3. Bleeding the brake
Bleeding the brake is the procedure whereby new brake fluid is introduced into the system either
as a replacement or to flush out any trapped air.
There are several reasons why a bleed operation may be necessary, for example shortening a
brake hose, changing the brake fluid, or to remedy a situation described later in the
troubleshooting guide (section 4).
There are two distinct procedures for bleeding your disc brake depending on which brake system
you have purchased, please make sure you select the correct procedure. But first a few important
notes on brake fluid.
Brake fluid
This Hope disc brake contains DOT 5.1 hydraulic brake fluid which is available from cycle retailers
and motor accessory stores. If you cannot obtain DOT 5.1 then DOT 4 is acceptable but you must
flush out all the old DOT 5.1 first.
Use of other types of brake fluid, in particular mineral oil, will seriously damage your brake and
cause brake failure.
Please read the care instructions that come with the DOT brake fluid, in particular we draw your
attention to the following:
•
Use only new brake fluid from a closed bottle and replace the bottle’s cap afterwards to prevent
contamination of the fluid (DOT 5.1 fluid absorbs moisture).
•
Brake fluid will strip paint so wipe off any spillage immediately and clean the area with isopropyl
alcohol.
•
Brake pads contaminated with brake fluid will need replacing because the braking performance
of the pad will be greatly diminished.
•
Discard old brake fluid in a responsible manner and do not pollute drains or the environment.
Bleeding the Closed 2 disc brake
Item number references refer to the diagram of the Pro lever (download separately).
Wear safety glasses.
1. Remove the wheel and brake pads to prevent contamination.
2. If necessary reposition the brake lever so that the lever and master cylinder is horizontal to the
ground.
3. Remove the master cylinder cap (item 23) using a 26mm spanner.
4. Place the closed end of an 8mm spanner over the bleed nipple on the brake caliper. Fit a length
of clear plastic hose (approximately 30cm) onto the bleed nipple and place the free end into an
empty container. The hose should be a snug fit and not fall off, the free end does not need to
be submerged under brake fluid.
5. Fill the master cylinder reservoir with brake fluid.