Question

Technician A says most shops use a spray wash cabinet to degrease their engine blocks. Technician B says some shops dip their major engine parts in a hot or cold caustic solution for deeper cleaning. Who is correct?

Answer 1

Both Technician A and B are correct in their statements about cleaning engine blocks. Technician A discusses spray wash cabinets, while Technician B mentions caustic baths for deeper cleaning.

Step-by-step explanation:

Both Technician A and Technician B are correct. Engine blocks need to be thoroughly cleaned to ensure proper operation after rebuilding, and different shops use various methods to achieve this. Technician A is referring to a common practice where a spray wash cabinet is used to degrease engine blocks, which effectively removes oil and grease with detergent and hot water. On the other hand, Technician B mentions the use of a caustic solution, which involves soaking engine parts in a hot or cold caustic bath that can provide a deeper clean by breaking down tougher grime that a spray wash might not remove.

These caustic solutions often contain different chemicals for cleaning purposes, and the practices mentioned by both technicians reflect the range of methods used in the industry. However, it's important to note that acidic cleaning agents, typically used for removing inorganic deposits like scaling, comprise strong mineral acids along with chelants, surfactants, and corrosion inhibitors.

Answer 2

Technician A

Step-by-step explanation:

While technician B is only partially correct, the statement of the technician A is completely true. Most shops use a spray wash cabinet, which is similar to a dishwasher that contains a strong soap and hot water solution. The solution is sprayed at parts, that are placed on a turntable, under high pressure, successfully removing oil, grease, and dirt.

As the technician B stated, some shops dip major engine parts in a hot caustic solution (but not a cold one). This method is called hot tanking, and although it cleans the engine parts well, it rarely removes all of the rust and oil paint. Due to environmental issues, this method is being used less and less.