Parts and consumables:
- Brake fluid type DOT-4
- Rags
- Cloth gloves
- Funnel
Note:
The reservoir of the brake master cylinder simultaneously serves as a supply reservoir for the master cylinder of the clutch release drive on vehicles with a manual transmission.
Despite the fact that a brake fluid level sensor is built into the reservoir of the master brake cylinder, we recommend that you periodically check the fluid level on the Toyota Corolla visually.
We recommend that you check the level before each ride, and, if necessary, add fluid to the tank. If you have to add brake fluid to the reservoir quite often, find and fix the problem.
When changing the brake fluid in the system, remember or write down the brand of fluid to be filled in order to use the fluid of the same brand when refilling.
Checking the level and adding brake fluid Toyota Corolla
1. Place the vehicle on a level, horizontal surface and lift the bonnet. The reservoir is installed on the brake master cylinder on the left side of the engine compartment near the bulkhead.

2. Visually check the brake fluid level in the Toyota Corolla reservoir. It should be between the "MIN" and "MAX" marks on the tank body.

Note:
Access to the brake fluid reservoir from above is hampered by the bulkhead lining. For ease of use, remove the cladding.

3. If the level of the brake fluid is below the "MIN" mark, pull on the edge and remove the reservoir cap.

4. Add brake fluid to the Toyota Corolla reservoir up to the “MAX” mark.

5. Close the reservoir cap tightly and wipe up spilled liquid with a cloth.

WARNINGS:
Contact with brake fluid on wires, plastic or painted body parts can damage them. If liquid spills on these parts, wipe them off immediately with a clean cloth.
A gradual decrease in the brake fluid level in the absence of leaks indicates, most likely, the need to replace the brake pads. Check the condition of the brake pads (see "Checking the brake system"). Untimely replacement of pads leads to costly repairs (replacement of brake discs and calipers)! Pay particular attention to the condition of the clutch master and slave cylinders. They can also cause a drop in the brake fluid level in the reservoir.
Source: http://toyotauto.net/corolla/proverka-urovnya-i-dolivka-tormoznoy-zhidkosti-v-bachok-gidroprivodov-tormoznoy-sistemy-i-vyklyucheniya-scepleniya.html