Document ppDyk7V32Gd4Ra92EgQxKw6yE

Inter Office Fnrd Farts and Sendee Division May 29, 1981 Mr, H. E. Hamburg /ce Mr. Q. G. Cllckard V Mr. E. J.fEiley ' Subject; EPA/OSHA Asbestos Exposure Program, for Brake Mechanics Ref: 1. EPA letter of 4/Z7/81 2, A. B. M. Houston letttter of 5/21/81 Vfe have reviewed the EFA letter and attachments end also Mr. Houston1 a letter and offer the fallowing canmsntst 1, She Training and Publications Eept. has published warnings in the brake section of the Car and Truck Shop Manuals regarding the t>] hazard of air blowing asbestos dust recommended the use of proper equipment for dost removal. Copies of this information are attached for your use. 2. The Training and Publications Dept, baa had no brake training programs in recent years because there has been no new tech nology on brake service requirements. Accordingly, we have not published training Information on asbestos dangers and bundling procedures. ' Attachments E. F- Prieba 105574 007386 PRODUCED BY FORD 12-0'*-20 General Hydraulic Brake Service 12-01.20 REMOVAL AND INSTALLATION 'RAKE DRUM . VEHICLES THRU 3000 SERIES Use the following service procedures for both nydrauiic and oir brakes. FRONT BRAKE DRUM 1. Raise the vehicle until the tire clears the floor and remove the wheel and tire from the hub. Loosen the brake shoe adjusting screw until the shoes no longer touch the broke drum. Remove Ihe grease cap and the gasket (if equipped) from the hub. 2. On vehicles with 9,000 lb front axles and hydraulic brakes, remove the locknut, locking ring, dimpled washer and adjusting nut. On alt other axles, remove the cotter pin, adjusting nut and flat washer from the spindle. 1 3. Remove the outer bearing cone and roller assembly. Pull the hub and drum assembly off the wheel spindle, 4. Remove the front wheeLto-hub retaining nuts jar nm and tire attaching nuts). Remove the wheel (or nm and tire) from the hub and drum. 5. Remove the broke drum retainers and attaching bolts, screws or bolts and nuts, 6. Remove the brake drum from the hub. 7. Check the drum for damage or wear, and repair nr replace if necessary. If a new drum will be installed, be sure to remove the protective coating with degress er. Install new grease retainer seals whenever a wheel and hub li removed. 8. Place Ihe brake drum to the hub and install the retainers and retaining baits, screws, or bolts and nuts. 9. Install the hub and drum on the wheel spindle Keep the hub centered on the spindle to prevent damage te the grease retainer or the spindle threads. 10. On vehicles with 9,000 lb front axles and hydraulic brakes install the outer bearing cone and roller at terribly, and the beering ad/uiting nut. On ail other axles, Install the outer bearing cone and roller end flat washer on the spindle. Install the adjusting nut. 11. Install the wheel and tire an the hub. Then install the damps (if applicable) and the wheel stud nuts. 12. While rotating the wheel, tighten the adjusting nut ta specification. Adjust wheel bearings os described in Group 11, 13. Or vehicles with 9000 lb front axle end hydraulic brakes, install the dimpled washer with the dimple indexed in One of the holes in the adjusting nut. Install the locking ring lock nut and tighten to specification (refer to Group 11). Bend the locking nng over a flat of the lock nut. 14. Install the gasket (if equipped) and the grease cap, and tighten the wheel stud nuts to specification [refer to Group 11). Install the hub cap [if equipped), and adjust the brakes at described in this Port. OVERHAUL r Removal of dust and dirt from broke assemblies f should be done by using the Rotunda Brake Vacuum i [340009) or equivalent or Rotunda broke parts washer (mode/ 4500 Id) or equivalent, brake assembly dust and dirt should not be removed by either blowing off with an air gun or vacuuming with a standard industrial vacuum because a health hazard from breathing asbestos dust may develop. Also, any machining done j ] on brake linings or pods should be done using properly I ` exhaust ventilated equipment. BRAKE DRUM REF1N1SHING Minor scores on a brake drum can be removed with fine emery doth, provided the emery is thoroughly deaned off the drum after the operation. BRAKE DRUM REFIMtSHING Miner scares on a brake drum can be removed with fine emery doth, provided the emery is thoroughly deaned off the drum after the operation. A badly scored, rough, or out-of-round drum should be ground ar turned on c drum lathe. Do not remove ov mar* material from the drum thon it necessary ta ide o smooth surface for the broke shoe contact. vice drum maximum broking surface diameter is sftown an each brake drum (Fig. 10). Brake drums which exceed the maximum braking surface diameter shown on the brake drum, either through wear or refinishing, must be replaced. FIG. 10 Brake Drum Maximum Braking Surface Diameter Marking Location--Typical Medium--Heavy Truck Shown ' On all medium and heovy trucks, the maximum broking surface diameter specification, which is shown on each broke drum, allows for O.OdO-inch machining cut over the original nominal drum diameter, plus 0.030inch additional wear before the drum must be replaced. After refinishing the broke surface runout must not exceed 0.070-ineh total indicator reading, measured from the bearing cup. 007387 PRODUCED BY FORD 007388 12 til'd* Hyitlriljflti Brakes fumalsl Seivli.a uniM ,, icompiew axle set) on front wheels as reqiured The rubber caliper insulators and the plastic sleeves must be replaced when linings are replaced 3 Visually check the caliper. If the caliper housing is leaking, it should be replaced. If a seal is leaking, the caliper must be disassembled and new seals installed. If a piston is seized in the bore, a new caliper housing is required. Reler to Part 12*20 for disc brake rotor resurfacing procedure. Service Precautions 1 Grease or any other foreign matenal must be kept off the lining surfaces of the rotor and external surfaces of the hub dunng service operations. In handling the rotor and caliper assemblies, avoid deformation of the brake rotor and mekmg or scratching of brake linings 2 If a caliper piston is removed for any reason, the piston seal must be replaced 3 Dunng removal and installation of a wheel assembly, exercise care not to interfere with the caliper splash shield or the bleeder screw fitting 4, Front wheel bearing end play is critical and must be within specifications 5 To avoid bending or damaging the rotor splash shield on full nght or left wheel turns, be sure the vehicle is cantered on the hoist before servicing any front end components. 6 Riding of the brake pedal (common on left-loot applications) must be avoided during vehicle operation 7. The wheel and tire must be removed separately from the brake rotor, unlike drum brakes where the wheel, tire, and drum can be removed as a unit. 8 Do not attempt to clean or restore any oil or grease-soaked brake linings. When contaminated linings are found, they must be replaced in complete axle sets. 9 Always replace rubber caliper insulators and plastic sleeves when replacing linings. Do not lubricate the slide pins. 10 Caliper slide pins must be hand started into spindle before tightening This is to insure that the large diameter ot pin is through outer shoe holes to prevent binding or bending. IJ hazard Irom breathing asbestos dust may develop. Inspect the brake shoes for excessive lining wear or shoe damage If the lining is worn within 1 /32 inch of the rivet heads or if the shoes are damaged, they must be replaced. Replace any lining that has been contaminated with oil, grease, or brake fluid. Replace lining m axle sets. Prior to replacement of lining, the drum diameter should be checked to determine that the brake drum braking surface diameter is within specification by using the Rotunda brake drum micrometer (model 100010) or equivalent If the braking surface diameter exceeds specification, the drum must be replaced, 4. Check the condition of brake shoes, retracting spnngs, hold-down spnngs, and drum for signs of overheating If the shoes have a slight blue coloring, indicating overheating, the retracting and hold-down springs should be replaced Overheated springs lose their pull and could cause the new lining to wear prematurely, If not replaced. If the brake drums are heat spotted. Indicating an overheated condition, they shoutd be replaced. 5. Inspect all other brake parts, and replace any that are worn or damaged 6. Inspect the brake drum and, if necessary, refinish. Reler to Rotunda Catalog Wheel Service, for a description ol the various types of brake lathes available. The maximum inside braking surface diameter is shown on each brake drum (Fig. 21). If the maximum inside braking surface diameter shown on the drum is exceeded either by wear or refintshing, the drum must be replaced. Refer to Part 12-02 lor refirushing. Drum Brakes 1. Remove the wheel from ihe drum, and remove the drum, Part 12-02. ____ _ /Removal of dust and dirt from brake assemblies 1 should be done by using the Rotunda brake I I vacuum (model 340009) or Rotunda brake parts f washer (model 650016) or equivalent Brake assembly dust and dirt should not be removed by (blowing off with an air gun because a health j FIO. 21 Location of Brake Drum Maximum Inside Surface Marking* Brake Booster Check the booster operation as noted under Power Brake Functional Test II the brake booster is damaged or inoperative, replace it with a new booster. The brake booster la serviced only as an asssmbty, Including the check valve. PRODUCED BY FORD