Replacement of front / rear brake lines

I decided to replace the nine years old brake lines due to safety and performance for the R1 bike. Meshed brake line does not have braking force reduction due to expansion of the rubber line under high braking.  I ordered Galfer Stainless steel front / rear brake line kits  on eBay.

I was surprised because these were Made In USA.  The upper is front brake lines, the lower is rear brake line. Again the kit does not have the installation instruction.


I bought 30cc syringe and 10cc syringe, 30cm of rubber tube to use the reverse bleeding technique of brake fluid.

Front brake line replacement


DOT4 brake fluid

Brake fluid cleaner

Front brake line kit: two meshed brake lines, one long union bolt, two short union bolt, six copper washers


Philips screw driver – brake fluid reservoir cap

8 mm wrench – bleeder screw

6 mm hex key – union (banzo) bolt on the caliper

5 mm hex key

14 mm wrench, 14 mm socket – union bolt in the kit

3/8in ratchet wrench

wire cutter

ziptie x10

A bucket of clean water with rag

First version of brake fluid pump:

30cc syringe, ziptie, tube whose inner diameter is 6 mm.

6 mm hex key for the union bolt


The front brake line assembly is one piece that the Y connector fuses three brake lines.


The leakage of brake fluid at the bleed screw was too much, I ended up spending two hours to bleed the front brake system using the conventional technique written on service manual:

  • Tight the bleed screw on the caliper
  • Squeeze brake lever four to five times and hold it
  • Loose the bleed screw on the caliper, let the fluid comes for few seconds then tight
  • Repeat above steps till there is no air bubble



The right brake line is on the bottom.

The brake lines are facing same direction. It’s right way.


Wrong way 20170511_0157


Rear brake line replacement

This time I used clear tube whose inner diameter is 6 mm. After loosening the bleed screw, secured the tube with ziptie. I drained brake fluid in the system before I removed the old brake line.

8mm wrench failed to loose the bleeder screw instead it damaged it. I had to use a small vise-grip which looked absurd because I got the brake fluid replacement from a bike shop few weeks ago.


The rear foot peg mount bolts were really tight. I used 6mm hex key I bought, axle nut wrench, and extension handle in Yamaha tool kit to loose.

I did not leave any scratch mark on the frame so I put a package envelope behind the rear foot peg when I was to loose the union bolt of master cylinder.

I used 5mm hex key and flat screw driver to disconnect the brake line.

Setup for the reverse bleeding of brake fluid

I connected 50cm of clear tube to 30cc syringe as a pump, temporarily mounted it on the reflector bracket using a ziptie. Then insert brake fluid using 10cc syringe in multiple times until the tube and syringe is filled with brake fluid.


To get rid of air inside the tube, squeeze the tube with thumb and index fingers. The brake fluid would flow through eventually and remove any air pocket.


The volume of brake fluid in the pump is bigger than the rear brake system. I was slowly pushing the pusher of syringe while watching the level of reservoir to prevent overflow of the fluid.  I did remove the fluid using 10cc syringe two or three times. Once there was no air bubble in the reservoir, I stopped reverse bleeding. And I did the conventional bleeding for about ten minutes.


Cleaning brake fluid

Brake fluid cleaner, water.

About janpenguin

Email: k2.mountain [at] gmail [dot] com Every content on the blog is made by Free and Open Source Software in GNU/Linux.
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