DOT 2 brake fluid is mineral based and should not be mixed with any other DOT rated fluid. DOT 3 and DOT 4 are glycol ether based. You can mix DOT 4 with DOT 3 brake fluid, but never add DOT 3 to DOT ...

Air in the brake system can make your brake pedal feel spongy and vague. You should flush the fluid every two or three years, ...

the segment's best-selling midsizer takes either DOT 3 or DOT 4 brake fluid. To be sure which one is right for your Taco, simply check the brake fluid reservoir cap or leave it to the dealer.