All models have the brake master cylinder reservoir on the left side of the firewall under the hood. Trucks and 4Runners with manual transmissions use a hydraulic (fluid actuated) clutch. The clutch fluid reservoir is located in the same area as brake reservoir. The clutch master cylinder uses the same fluid as the brakes, and should be checked at the same time as the brake master cylinder.
Use only Heavy Duty Brake fluid meeting DOT 3 or SAE J1703 specifications.
The fluid in the brake and/or clutch master cylinders should be checked every six months or 6,000 miles (9,600 km). Check the fluid level at the side of the reservoir. If fluid is required, thoroughly wipe the top of the reservoir and the sides of the plastic housing with a rag before opening. The fluid must be kept free from dirt and grit. Fill the reservoir to the MAX line in the reservoir. NEVER overfill the reservoir. Install the reservoir cap, making sure the gasket is properly seated in the cap.
It is normal for the fluid level to fall as the disc brake pads wear. However, if the master cylinder requires filling frequently, you should check the system for leaks in the hoses, master cylinder, or wheel cylinders.