What should be checked for brake fluid maintenance?

The process of brake fluid maintenance is critical for ensuring the safe and efficient operation of a vehicle’s braking system. Checking the fluid level is vital because insufficient brake fluid can lead to reduced braking efficiency and potentially catastrophic failure. Additionally, assessing the contamination level is essential, as brake fluid can absorb moisture over time, which can lead to corrosion of internal components and a decrease in the fluid's boiling point. Contaminated brake fluid can compromise braking performance, resulting in longer stopping distances and increased risk during driving.

The other aspects, while relevant to the overall health of the braking system, are not primary checks for brake fluid maintenance. The color and viscosity of the fluid can provide some indication of its condition, but they do not directly impact performance as significantly as fluid level and contamination. The temperature of the fluid is not typically monitored in routine maintenance; it's more of a concern during extreme driving conditions. Finally, checking the pressure of the fluid in the lines is more related to diagnosing brake line systems rather than routine fluid maintenance checks. Therefore, the most crucial factors in brake fluid maintenance focus on ensuring proper levels and cleanliness of the fluid to maintain optimal braking efficacy.