Technician A says it is acceptable to use brake cleaner to clean throttle bodies. Technician B says it is acceptable to mix DOT 5 brake fluid with DOT 3 brake fluid. Who is right?

Using brake cleaner to clean throttle bodies is generally not recommended because many brake cleaners contain strong solvents that can damage the plastic and rubber components commonly found in throttle bodies. These solvents might degrade seals and gaskets, potentially leading to vacuum leaks or other malfunctions. Therefore, Technician A's statement is incorrect.

Similarly, mixing DOT 5 brake fluid with DOT 3 brake fluid is not advisable. DOT 5 brake fluid is silicone-based, while DOT 3 is glycol-based. Mixing these two types can lead to significant issues because they are not compatible with each other. This incompatibility can affect the braking system's performance and lead to brake failure.

Given these reasons, neither technician's statement holds true, confirming that the correct response is that both statements are incorrect.