The brake light is on in my 2007 Toyota Tacoma 4WD v6. The recurring pattern has been that I would fill up the brake fluid but then it would drop below the minimum mark after just a few days. It doesn't go below though. The brakes function fine. I have no clue why this happens.
I just went to AutoZone to get more brake fluid and picked up
DOT 3 from the shelf because that's what I had been getting. I asked the associate just to confirm that's the right kind for my truck and she checked in the computer and said I needed 'DOT 3/4'.
Q1. Was she correct?
Q2. If A1 is yes, could my brake problems be coming from the wrong kind of brake fluid?
Q3. Can I replenish the existing DOT 3 with DOT 3/4, i.e. is it bad if they mix?
Q4. Do I need to bleed out the whole system?