© 2012 Delmar, Cengage Learning Automotive Plumbing: Tubing and Pipe Chapter 24

© 2012 Delmar, Cengage Learning Objectives Describe the different types of tubing used on automobiles Understand the different types of tubing connections Repair damaged tubing

© 2012 Delmar, Cengage Learning Introduction Tubing and pipe –Found on automobiles and on shop equipment This chapter covers: –Tubing and pipe service –Different types of plumbing parts –Connectors used with tubing and pipe

© 2012 Delmar, Cengage Learning Tubing Often called “line” –No threads at its ends –Can be made of copper, steel, or plastic Manufacturers choose the least expensive alternative to do the job safely Copper tubing –Can be soft or rigid –Work hardens Plastic –Used for vacuum or oil pressure lines

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Tubing (cont'd.) Steel tubing –Galvanized to prevent rust –Double-walled when used for brake lines –Armor: Steel coil around outside of a break tube Tube fittings –Many types of fittings join tubing to components –Connectors are used between tubing and parts (e.g., oil pump)

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Flared Connections Used when two steel fuel lines are connected –Flare connection is suited for high-pressure applications –Must be used for brakes or power steering Two kinds of flares: –Double flare (SAE) –Bubble flare (ISO)

© 2012 Delmar, Cengage Learning Flared Connections (cont'd.) SAE-type double flare –Used with an inverted flare nut SAE flare: can be a either a single or double –Single flare: not used on small automotive tubing ISO flares: used since the early 1980s –Bubble is formed in the line near its end

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Compression Fittings Compression fittings: flareless fittings –One kind uses a brass sleeve called a ferrule To install a compression fitting: –Slide nut onto tubing –Slide the sleeve onto the tubing –Insert the tubing as far into the fitting as possible –Tighten one and a fourth turns after both fittings have contact

© 2012 Delmar, Cengage Learning Compression Fittings (cont'd.) Characteristics –Should not be used on high-pressure applications –Can also be used with rigid plastic tubing –Double compression fitting: no separate sleeve but compresses front part of nut against tubing –O-ring connections: used to seal fittings Unions –Join two pieces of tubing together

© 2012 Delmar, Cengage Learning Pipe Fittings Pipe threads are used for: –Heater outlets –Oil gallery –Coolant drain plugs –Oil and coolant temperature sending units –Compresses air lines in the shop Fittings on copper, brass, or iron pipe –Use tapered threads

© 2012 Delmar, Cengage Learning Pipe Fittings (cont'd.) Characteristics –Size of pipe thread Determined by the size of the piece of pipe –Pipe coupling Joins two pipes –Street elbow Male thread on one end –Close nipple Tapered threads on each end that join in middle –Long nipple Plain pipe separates the threads

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Shutoff Valves Also called draincocks –Often found on the bottom of a radiator –Turning end of valve opens or closes it –Plastic radiator tanks usually have a plastic drain valve

© 2012 Delmar, Cengage Learning Tubing Service Tubing comes in precut lengths with flare fittings Considerations –Do not kink bulk tubing when unrolling –Use a tubing wrench or flare nut wrench to loosen a flare fitting –Damaged steel fuel lines can be cut and repaired New lines fabricated with a flaring tool

© 2012 Delmar, Cengage Learning Tubing Service (cont'd.) Cutting tubing –Cut square on the end –Tubing cutter is tightened against tubing then rolled around it –Remove burrs Bending tubing –Too sharp of a bend will cause a kink –Install fittings and flare both ends before bending tubing

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Tubing Service (cont'd.) Bending spring: installed over the tubing –Prevents kinking Steel lines: should not have long, straight runs Long runs: should be supported with clamps Flaring the ends of tubing –Double flare or an ISO flare Double flaring is a two-step procedure ISO flaring –Bubble or ridge is formed in the line a short way back from its end

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Installing Tubing When installing tubing –Leave first fitting loose Union repairs –Union is used to repair a damaged line Better repair than hose for high-pressure lines Using hoses to repair tubing –When a section of steel fuel line is damaged, it is best to replace it and its flared ends and fittings

© 2012 Delmar, Cengage Learning Transmission Oil Cooler Line Repairs Union –Best repair for a transmission cooler line Kinks are often repaired with hose –If rubber hose is used: flare both ends of the metal tubing –Edges of a double flare can cut the rubber hose over time

© 2012 Delmar, Cengage Learning Nylon Fuel Injection Tubing Nylon line is connected to steel line –Push connector is used –Some nylon lines are coupled together with a “spring lock” connector –There are two O-rings on the male coupling –If the garter spring is damaged or missing, it can be replaced in the coupling

© 2012 Delmar, Cengage Learning Pipe Service Pipe is cut with a pipe cutter –Resembles a large tubing cutter Pipe dies –Form threads on the outside of the pipe Thread sealer –Used between threads After hand tightening pipe –Tighten further a minimum of two and a half turns