1 / 22

Automotive Hoses

Automotive Hoses. Chapter 23. Objectives. Correctly identify automotive hose sizes Explain the different types of hose materials, clamps, and their applications Inspect all types of hoses for damage Correctly remove and replace all types of hoses. Introduction.

bat
Télécharger la présentation

Automotive Hoses

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Automotive Hoses Chapter 23

  2. Objectives • Correctly identify automotive hose sizes • Explain the different types of hose materials, clamps, and their applications • Inspect all types of hoses for damage • Correctly remove and replace all types of hoses

  3. Introduction • More than ten different types of hoses • Hoses are found on the: • Radiator • Heater • Automatic transmission • Fuel and emission systems • Brake system • Lubrication system • Air-conditioning system

  4. Hose Construction • Hoses consist of an inner rubber tube, reinforcement, and outer rubber cover • Bonded with adhesives • Different tubes and covers • Different reinforcement • Withstand different amounts of pressure • Incorrect hose can result in a fire or damage • Use caution around refrigerant lines

  5. Hose Size • Hoses are sized according to inside diameter • Common heater hose sizes • 5/8 and 3/4 inch • Common fuel hose and line sizes • 5/16 and 3/8 inch for pressure hoses • 1/4 inch for return lines

  6. Unreinforced Hose • Unreinforced rubber • Used for vacuum hose, windshield washer hose, and drain hose • These hoses are under little strain • Can still present safety problems if they fail • Harden with age and are routinely replaced

  7. Radiator Hose • Radiator hoses designed to have a burst strength • Five to six times working pressure of the cooling system

  8. Hose Types • Straight: used for fuel hose, vacuum hose, or heater hose • Kinks when bent too much • Curved: preformed with required bends • Vulcanizing cures rubber and sets it in a given shape • Universal: clamped on one end and bent until it assumes the desired shape • Reinforced with wire

  9. Hose Types (cont'd.) • Formable: has metal wires inside • Allow it to be bent without kinking • By-pass: molded to the correct curves • Must be cut to length, depending on the application • Fuel hose: fuel delivery systems use metal tubing • Connected to tank and engine by rubber hoses • Must resist abrasion, oil, temperature

  10. Hose Types (cont'd.) • Carburetor fuel hose: braided reinforcement with synthetic rubber cover and inner tube • Does not react to gasoline or alcohols • Fuel injection hose: designed for higher pressure • Burst strength more than 900 psi • Transmission oil cooler hose: withstand constant temperature of 300°F and 450 psi • Power steering hose: pressure and return line

  11. Hose Types (cont'd.) • Power brake booster hose: must be reinforced and fuel-resistant • Brake hose: must be flexible and able to withstand high pressure • Burst strength of 5,000 psi • Rubber reinforced • Brake tubing has male fittings on both ends • Air-conditioning hose: reinforced and have crimped connectors • Must withstand high pressures

  12. Hose Clamps • Tighten hoses to their connections • Worm gear clamps: reusable and easy to install • Twin wire clamps: strong but may cut into the hose if over-tightened • Rolled edge clamps: designed not to cut into the hose • Screw tower clamps: strong but difficult to remove • Spring clamps: can cut into a hose and do not provide a strong enough clamping force

  13. Hose Inspection • Considerations • Check hoses for hardness by bending them • Oil causes hoses to swell and deteriorate • Check rubber on the inside for deterioration • Electrochemical degradation (ECD) occurs when the hose and fittings form a galvanic cell • Causes small cracks inside hose • To check for ECD squeeze the hose in several places to see if rubber feels consistent • Any questionable hose should be replaced

  14. Replacing Hoses • Considerations • Drain off coolant to replace a coolant hose • Do not force hose if it does not come loose from its fitting • Ensure clamps are in good condition and tight • Heater hoses on a car may be two diameters • Hose should not interfere with manifolds, belts, spark plug cables • Hose should not be damaged by engine or accessories • Compare new power steering hose to old one

  15. Replacing Hoses (cont'd.) • Use the correct fluid when refilling the power steering system • Bleed air from power steering by turning the steering wheel back and forth • Replace fuel injector hoses before failure • Use hoses with crimped ends • Special hose is required for the in-tank fuel pump • Fuel injection lines maintain pressure even when the engine is off • Factory-installed air-conditioning systems come with a very wide variety of styles

  16. Replacing Hoses (cont'd.) • Worm gear hose clamps with 3-barb fitting is not recommended • Avoided with R-134A beadlock fittings

More Related