Remove the cap from the brake fluid reservoir and use a syringe to pump out the brake fluid.
Place a clean rag under the master cylinder to collect any leaking brake fluid.
Remove the screw securing the reservoir to the master brake cylinder.
Pull the reservoir up and away from the master cylinder.
Figure 11.37. Removing the sealing ring from the brake master cylinder
Remove the O-rings from the brake master cylinder (figure 11.37). Check the condition of the sealing rings. If they are hardened or damaged, replace them.
Lubricate the new O-rings with fresh brake fluid and install them into the master cylinder.
Screw in the screw that secures the reservoir to the master cylinder.
Pour brake fluid into the brake system reservoir.
(The text is taken from the specified website toyotaman.ru)
Bleed the brake master cylinder.