Chapter 3 Brake Tools, Shop Equipment, and Service Information 41 Copyright by Goodheart-Willcox Co., Inc. Vacuum Cleaning Systems Many shops use dry cleaning systems to remove brake dust from brake assemblies. Th ese systems include standard shop vacuum and high effi ciency particulate air (HEPA) vacuum systems. Th e traditional shop vacuum, Figure 3-32, operates in the same manner as a conventional household vacuum cleaner. Due to the extremely small size of asbestos particles, they can escape from the relatively ineffi cient fi lters used with the typical shop vacuum. Th erefore, shop vacuums are no longer recommended for brake cleaning. However, most of these vacuum cleaners are wet and dry systems, and are useful for removing spills, or vacuuming up water aft er the shop is hosed down. Th e high effi ciency particulate air (HEPA) vacuum cleaner system, uses a fi lter called a HEPA fi lter. Th e HEPA fi lter can trap extremely small particles, including asbes- tos particles. To keep the HEPA fi lter element from quickly becoming clogged, the vacuum usually has one or two coarse fi lter elements which trap large particles before they reach the HEPA fi lter. Th e HEPA fi lter–equipped vacuum is the only recognized method of vacuum cleaning brake parts. Before using a HEPA vacuum cleaner, check the fi lter condition and check all hoses for tightness. Wet Cleaning Systems Th e simplest type of wet cleaning system is the can of brake cleaner. Th e spray can is pointed at the brake assembly to be cleaned, and the brake dust is washed from the unit. For best results, spraying gently from top to bottom, wet down Goodheart-Willcox Publisher Figure 3-32. A portable shop vacuum for wet or dry clean-up. the assembly fi rst, then use a stronger spray to wash the dust from the parts. Place a shop rag or waste cloth under the wheel and allow the solution to drip into it. Th e wet cleaning station, Figure 3-33, uses water mixed with a solvent or detergent. Air pressure is used to spray the solution onto the wheel brake parts. Aft er the assembly has been thoroughly wet down, the spray force can be increased to wash the dust from the wheel. Th e solution collects in the pan where it can be disposed. Th is type of wet cleaner collects more dust than spray can cleaners. Warning: The dust collected by any of these methods may contain asbestos and should be treated as hazardous waste. Used shop rags, filters, and contaminated cleaning materials should be placed in a closed container and disposed of along with other hazardous waste. Brake Service Equipment Th e following equipment is needed to perform a complete repair to the brake system. Th ese pieces of equipment rep- resent a large investment, but must be available if brake ser- vice is to be performed correctly. Th ese tools are considered Goodheart-Willcox Publisher Figure 3-33. A brake wet cleaning station. The cleaning solution is a mixture of water and organic solvent.