Document KRLVyeq7qmx00agqjVE2x0RXN

FILE NAME: AMMCO (AMC) DATE: 1969 DOC#: AMC018 DOCUMENT DESCRIPTION: Product Operating Instructions 0149 TOOLS required for Brake Jobs These special tools are among the most impor tant tools required for brake service work. They are designed to save time and help do the job right. NO. 2650 BRAKE H A N O TO O L KIT Contains toots for removing, replacing, adjusting brake shoes; bleeding brake systems, etc. M OD EL 7150 BEARING PACKER Fast--easy to use. Eliminates messy cleaning and inadequate hand packing. N o chance of air pockets. MODEL 7400 BRAKE BLEEDER For fa s t safe brake system bleeding. Design prevents possibility of air entering system. MODEL 9575 DISC BRAKE CALIPER HONE Handles all domestic and foreign cars. Driven w ith portable electric drill. Adjustable honing pressure. M O D EL 8 6 5 0 BRAKE SHOE A D JU S T IN G GAGE Quickly gives correct lining-lo-drum clearan ce before drums and wheels are installed. Transfers drum diameter directly to brake shoes. A must for selfadjusting brakes. No need to back car up to adjust brakes. MODEL 3750 o o MODEL 1650 BRAKE CYLINOER SURFACING H O N E S for brake wheel and mas ter cylinders. Flexible drive allow s honing wheel cylinders on the car. OSI-O MODEL 8500 BRAKE D R UM M IC R O M E T E R . Checks out-of-roundness TORQUE J as w ell as diameter Handles ___ WRENCHES Assure correct torque and compliance w ith fac drums 6 " to tory specs when tightening brake system com 16J4" . . with ponents Swrvcl Heed and Fixed Head Models extension b3r Mem ory feature (pointers hold reading) on Fixed to 26". Head Models. m HOW to do the C O M P L E T E Apfi? DRUM # brake job by Waller Alley DIRECTOR OF TRAINING AMMCO TOOLS, INC. NORTH CHICAGO. ILLINOIS SECTION I Drum B ra k e s .............. pages 2 - 1 4 SECTION II Disc Brakes ..............pages 1 6 - 2 9 SECTION III Diagnosing Brake Problems ........ pages 3 0 - 31 Copyright I9b9 AMMCO Tools, Inc. Nur Hi Chicago, Illinois P rim o rl in USA HOW TO PERFORM THE COMPLETE DRUM BRAKE JOB Figura 1 -- Checking the m aster e v a d e r tor a defective prim ary cup. Step No. 1 - Test the Hydraulic System. Check the operation of the master cylinder. A. Primary Cup. A defective primary cup may be detected by slowly and firmly depressing the brake pedal. If the brake * pedal becomes hard, then slowly fades to the floor, brake fluid is by-passing the primary cup or is leaking from some other part of the system. U sually, by inspecting the master cylinder reservoir for fluid level, you can get an indication of whether the primary cup has failed or some other hydraulic part is defective. Asking the car owner if he has had to replenish the flu id in the master cylinder recently often pro vides an answer. A defective primary cup w ill cause loss of pedal with no resulting loss of brake fluid. Rebuild or replace the master cylinder to correct a defective primary cup. 2 OlSt B. Secondary Cup. Loss of brake fluid can be the fault of a worn secondary cup. When the inside of the boot at the rear of the master cylinder is wet with brake fluid, the secondary cup has failed . When the master cylinder is bolted to a vacu um cylinder power brake unit, check the secondary cup for n leakage by removing the vacuum hose at the power unit. Evidence of fluid in the hose indicates a worn-out FiQ ura 2 -- C h e c k in g th a m a s te r c y lin d e r fo r le a k a g e a t th a s e c o n d a ry cup b y sp ue ea in g the m aster c y lin d e r boot. secondary cup. Replace or rebuild the master cylinder to correct a worn secondary cup. Step No. 2 - Check Stop Lights. When the master cylinder is be ing checked for operation, the stop lights are observed for proper operation. Inoperative stop tights could be due to: 1. Blown fuse in c irc u it. 2. Defective bulbs in tail light sockets. 3. Defective stop light switch. F igure 3 -- M ark a w h e a l s tu d and its cor* re sp o n d in g w h e e l s tu d h o le w ith cra yo n to m a in ta in the w h ee l b a la n ce a lte r a brake jo b. The stop light circu it is an important part of the complete brake job. Safety demands that the stop lights always be operating correctly. ^ Repair the stop light before the brake job is started; otherwise, it w ill |ie forgotten when the car is delivered to the customer. ^.^.p No. 3 -- Loosen Wheel Nuts. Remove the hub caps and loosen the wheel nuts. Mark one stud and its corresponding hole in the wheel to maintain wheel balance. When the vehicle has a tapered rear hubbed drum, remove the cotter-key from the rut and loosen the axle nut. Step No. 4 -- Support Vehicle off Floor. Support vehicle on jack stands under the bod/ of the vehicle. Do not support the vehicle under the axle or lower control arm since the stands w ill get in the way. Many rear wheels are d if fic u lt to remove from the rear axle because of low fenders. \ J T By placing the stands under the frame o f the vehicle, the wheels w ill hang down on their springs, resulting in easy removal of the rear wheels. Step No. 5 -- Remove Tires and Wheels ~ Remove a ll wheel nuts and place them in the hub caps for storage. Place the tire next to the brake assembly. Lay the wheel down with the outside or white-side 4 w all next to the floor. ^ Place the hub cap upside down in the wheel to prevent it from being scratched up. Use the hub cap to store brake parts. F igure 4 -- P iece hub ceg in s id e o f w heel to prevent scra tching th e ca p. N o tic e la b e l in g o f L. F. b ra k e d ru m . N o tic e a ls o th a t th e lu g nuts w ere re p la ce d on th e Studs to a llo w for ch a tte r free drum tu rn in g . A ll z 1959 through p re sen t m odel C h e v ro le ts have flo a tin g drums on the fro m hubs. Z S 1.0 Step No. 6 - Mark Identification on Drums. Mark each drum according to location on the vehicle, L.F,, Many vehicles have left-hand studs and nuts on the left side ol the vehicle and right-hand studs on the right side of the vehicle. Also, the front wheel bearing parts have run-in to each other, and mixing the bearings can cause premature failure. 4 Step No. 7 -- Measure Drums w ith a Brake Drum Micrometer. Remove the drums from the front spin dles. Use the spindle nut to help pull the inner bearing and seal. A. Check Drums. Measure all drums with a Brake Drum Micrometer. Determine whether the drums are worn beyond safe limits. Most drums are worn beyond safe limits if, after machining, the drums w ill be .060" greater than the original new car size. B. Check for Hard Spots. Excessive hard spots, (blue marks showing in the middle of the drums wear ing surface) may be cause for d is carding the drum. C. Check Drums for Out-of-Round. Measure the drum diameter in more than one location. V a ria tions in the readings indicate an out-of-round drum. Step No. 8 - Mount Largest R e y Drum 9k on Brake Drum Lathe. Check for Drum Wobble. Check mounting of drum on Lathe by making a light scratch on the drum's wearing surface while the drum is revolving. Loosen the Lathe's arbor nut and revolve the drum one-half turn. Make another trial cut with the tool bit. If the two scratch cuts are side by side, the drum is wobbling. A drum that has excessive wobble or lateral _ runout w ill cause the brake pedal / ~ ^ jto pulsate or move up and down as lithe brakes are applied. ' . . ,,.ep No. 9 -- Clean Front Wheel Bearings. While the rear drum is being ma chined or turned on the Lathe, the front wheel bearings are cleaned and inspected. Figure 5 -- C heck drum s w ith a Drum M icro m e te r. F ig u re 6 -- M o u ntin g o f re a r flo a tin g drum on th e D rum Lathe. F ig u re 7 -- U s e Dir n o * z ie to h e lp b lo w h idden grease from the wheel bear in g . C a u tio n - n e v e r s p in the bear~ mg as the ro lle rs m ay fly out o f the cage. A. Clean inside of Hub. Wash all of the excess grease from the wheel hub. Modern wheel bearing greases need only be packed into the wheel bearing separator cavities. B. Check the Bearing Races. 1. Pits or evidence of excessive bearing wear w ill be noticed on the surface of the bearing cup or races. Whenever the cup indicates bearing failure, replace the entire bearing assembly. 2. A wheel bearing cup (race) is pressed into the hub at the time o f vehicle manufacture. When a cup is replaced, care --^ must be taken so that the old cup is properly removed from the hub. If the old cup is driven out of the hub in a cocked manner, the hub bore i may be enlarged. The new bearing cup may now move or .spin inside the hub. Correct wheel bearing adjustment can not be achieved nor can Ihe front drum be accurately ma chined on the Drum Lathe if the bearing cup is loose in the hub. Figure 9 -- C hecking o ld brake shoes fo r w ear. Replace the hub and bearing Wear pattern on brake shoes may in d ica te cups if this condition is fou nd ^p a problem . Step No. 10 -- Mount the Other Rear Drum Use the same Lathe setting as was required to machine the first drum. Step No. 11 -- Inspect Old Shoes. While the other rear drum is being machined, look at each brake assembly. Check lining wear. Inspect the wear pat tern of the brake lining on all four brake assemblies. Normal brake lining wear w ill Z leave little or no brake lining in the center of the shoe. The ends of the lining shs*<'"" ' ' \ show nearly equal thickness. This coff tion exists because the shoe platform c \ _ . / not bend to conform to the arc or the drum. F ig u re 9 -- M ount a Iro n ! drum on th e The web of the shoe w ill not allow the shoe L a th e arbor. N o tic e a d ru m beam ing p ro te c to r betw een th e Lathe and the d r u m . T h is P r o te c to r h e lp s IO p re * v e n t c h ip s from e n te rin g th e hub. to flatten out. Whenever the shoe has more lining worn off one end of the segment than the other, these conditions might be present: 6 Ol 53 1. Misplaced anchor pin. The anchor pin was not correctly adjusted at the time of the last brake re-line. Check for an adjustable anchor pin. 2. ^ F Worn or distorted brake shoe. The anchor end of the shoe with repeated pounding of the shoe against the anchor may be deformed. The eye of the shoe is sometimes swaged flat which lets the shoe ride high on the anchor pin and in so doing, wears more brake lining off the heel or anchor end of the shoe than at the toe end of the shoe. Fioure 10 -- Hamovd springs from anchor p in . Tho to o l p re ven ts e xcessive d isto rt ion o f the sp rin g d uring rem oval. Step No. 12 -- Turn a Front Drum. Mount the worst front drum on the arbor of the Lathe. Use a bearing protector over the hub of the drum to prevent the chips from getting into the inner race. Step No. 13 -- Remove a ll the Shoes. Remove all the shoes from the backing plate. Test each spring before it is placed in the hub cap. EitheV use a spring tester or drop the spring on a cement floor to determine if the spring is still usable. A weak or excessively heated spring w ill bounce and/or vibrate when it contacts the floor. A good spring w ill hit the floor with a F ig u re 11 -- Wrre b ru s h b a c k in g p la t e >o rem ove d ir i and ru s t. Grasse on the b a c k in g p la te sh ou ld be removed w ith a so lven t. F ig u re 12 -- L o o s e n b le e d e r v a lv e w iih a socket type w rench. An open end wrench w ill o fte n rovnd o ff a bleeder v a lv e . dull thud. Observe the color of the springs. Color usually indicates a difference in spring tension. For ex ample, a Chevrolet uses a gray spring on the primary shoe and a black heavier spring on the secondary shoe. The stronger spring keeps the second ary shoejgainst the anchor pin at all times, reducing brake noise. Step No. 14 -- Turn the Other Front Brake Drum. Use the same machine setting as was used to turn the firs t drum. If either drum con tains hard spots, both drums must be ground. Step No. 15 -- Clean Backing Plates. F igure 13 -- Wheel C y lin d e r is rem oved from b eckin g p la te fo r d isa sse m b ly b ecause the w heel c y lin d e r p is to n stop s p re ssed in to the b ackin g p la te w ill not a llo w the p is to n s to come out o f th e c y lin d e r. Wire brush rust and dirt from the backing plates. If the ledges on which the shoes rest show evidence of deep scoring, the ledges should be ground down flush. Otherwise, the shoes w ill hang up as they slide over the grooved ledges. ^ Step No. 16 -- Inspect the Wheel Cylinders. A. Loosen the Bleeder Valves. Using a suitable bleeder valve wrench loosen the bleeder valve in each cylinder. Excessive corrosion may require com plete replacement of the cylinder be F ig u ra M -- H oning a w heel C y lin d e r w ith an in s p e c tio n cause the bleeder valve may tw ist off. hone. A lco h o l or brake flu id m ay be used as a h o n in g flu id . B. Wheel Cylinder Piston Stops. Many wheel cylinders cannot be disassem- bled w hile S till bolted to the backing plate. Wheel cylinder piston stops (a metal stamping that protrudes froma the backing plate) are to keep the cylinder pistons from coming out too far when the shoes are removed. These stops require that the wheel cylinders be unbolted from the backing plate and be pulled out away from the stops in order that the cylinders may be dis F igure 15 -- L ig h tly c o a t th e w heel c y lin d e r cups and assembled. p is to n s w ith assem bly flu id . Brake flu id may a ls o be used. C. Disassem ble the Wheel Cylinders. Observe the condition of the pistons Z when they are removed from the cylin ders. Minor corrosion can be scraped off of the piston head. If the brake fluid appears to be very dirty and dark in color, the brake system shi be flushed before the cylinders are b uilt or new ones installed. Flushing fluid is usually an alcohol base com pound which dissolves the residue in F ig u re 16 -- Rem oving th e w h e e l c y lin d e r from iha b ra k e h o s e . the lines and hoses. The fluid is usually placed in a Bleeder which is 8 P S LO F igure 17 -- D is c o n n e c t th e p a rk in g b ra ke c a ble . connected to the master cylinder. The flushing operation takes place until clear flushing fluid is coming from a ll four wheel cylinder locations. Brake fluid is then pumped through the lines with another Bleeder until fresh brake fluid is coming from the cylinders or lines. I D. Hone the Cylinders. A'Brake Cylinder Hone is used to clean the wheel cylinder, f-ither alcohol or brake fluid may be used as a ! honing fluid. A fte r the revolving Hone has been moved back and forth through the cylinder a few times, the cylinder should be flushed with alcohol and a clean shop towel pulled through the c y l inder, If no defects appear.,in the cylinder w a ll, the cylinder may be rebuilt. If any defect appears, the cylinder should be replaced. i Step No, T7 -- Rebuild the Wheel Cylinder i After the cylinders have been honed with an Inspection Hone and found to be free of defects, the cylinders may be rebuilt. Remove and clean the passages in the Bleeder valves. Then snugly tighten the Bleeder valve into its seat. Coat the wheel cylinder pistons and cups with a light film of assembly fluid. Put the wheel cylinders to gether. Bolt the cylinder to the back ing plate. Install the actuating pins inside the boots. fig u re 18 -- L ub rica te the p a rk in g brake c a b le s and c o n d u it w ith brake lu be . Slep No. 18 - Replacement of the Wheel Cylinder. Unscrew front cylinders from brake hose, 8e careful that the copper washer between the hose and cylinder is not lost. Dis assemble the new cylinders and clean if necessary. Reassemble the cylinder with assembly fluid. Screw the new cylinder onto the brake hose firmly. Bolt the cylin der to the backing plate. If the F io u rtt 19 -- C o ve r each o f ts a b a c k in g p la t e ledges >nh a light coal of brake lubrication, brake hose has even the sfig hti^^ twist, the hose Clamp On the frame must be disconnected and the twist removed from the hose. A twisted hose w ill unscrew itself from the wheel cylinder as the car is driven, resulting in loss of all the brake fluid and the brakes. Step No, 19 -- Disconnect the Rear Parking Brake Cables. The rear parking brake cables can be maladjusted which w ill cause dif ficulty when installing the rear shoes. Many times when the vehicle driver complains that the parking brake handle travels too far when he ap plies the parking brake, an inexperienced mechanic w ill assume that the brake cables have stretched. He w ill "take up the slack' in the cable by shortening it. He should have: f l ) pulled a rear brake drum and in spected the brake lining for excessive wear; (2) performed a minor A adjustment to the rear brakes to bring the shoes closer to the drum; TM and (3) adjusted the cable for "slack" if needed. Shortening the cable without first checking the rear brake shoe adjustment will cause the rear shoes to be held away from the anchor pin. In some cases the drum will not go over the brake shoes. Step No, 20 - Lubricate the Parking Brake Cables. Pull the cable toward the rear of the vehicle. Coat the exposed cable with brake lubricant. Pull the cable forward through the cable housing. Lubri cate the forward section of the cable. Pull the cable in and out of the housing until the cable is completely free. If the cable does not move, it has rusted to the housing. Replace the cable with a new one. Step No. 2T - Lubricate the Backing Plate Ledges With a High Melting Pi Lubricant, The lubricant will keep the shoes from causing a scrunching noise as' are applied. Do not apply too much; otherwise, the lubricant w ill bleed into the friction material on the shoe and cause erratic brake operation. When the vehicle has a brake design that uses an adjustable anchor pin, the anchor pin should be removed from the backing plate, lubricated, and reinstalled in the backing plate. 0 # F ig u re 20 -- G rin d b ra k e s h o e s to co rre s p o n d to th e b ra k e d ru m in which th e s h o e s a re to f i t . Since m ost a ll c a rs n o w h ave Servo brakes u sing a fix e d a nch or p in , th e shoes sh ou ld be ground to an anchor lo c a tio n . Step No. 22 -- Obtain the Mew Shoes. Sy using the make and model of the vehicle, find the shoes required for a particular vehicle in a brake shoe catalogue or a F.M.S.I. Brake Shoe Data Book, The first part of the shoe number indicates the F.M.S.I. (Friction Materials Standards Institute) number for the segments that are either bond or riveted to the core. The core is the steel part of the brake shoe. The last digits of the shoe number indicate the core number. For example, a a (1968 Chevrolet rear brake wjll require a 2006-228 | rake shoe. The No. 2006 indicates the fining segments. The N o .228 indicates the core number, if the drums were scored or out-of-round, they would have been machined oversize or larger than when the vehicle was new. The new shoes should have lining segments which are thicker than the standard (new vehicle brake lining thickness) shoes. A general rule to follow is to obtain brake shoes with over-size lining thick ness equal to the amount removed from one side F ig u re 21 -- C h e c k in g f i t u f gro un d shoe in drum. of the drum. If twenty thousands of an inch of material had been removed from one side of a brake drum, the brake lining should be at least twenty thousands of an inch thicker than the standard li 1 came on the vehicle when it was new. Most suppliers stock .030* ovi a lining which would be the correct lining if the drum had been machirn maximum safe diameter, or .060" greater than original equipment or sin Irum size. Step No. 23 -- Grind Brake Shoes to Match the Drums. Adjust the Brake Shoe Grinder so that the shoes w ill be ground to fit a dru that is slightly smaller than the drum into which the shoes are to fit. The Figure 22 -- in s ta ll the brake shoes w ith proper ho id-dow n s p rin g to o l. F ioure 23 -- A d ju s t Brake Shoe S e ttin g G auge to Drum diam eter grinder is usually set to the drum size less .030. For example, if the drum diameter was 11.050" or .050" over-size, .030" would be subtracted from 11.050" which is 11.020". The shoes would be correctly ground for the 11.050" drum if the grinder is adjusted to 11.020". By grinding the brake shoe to a drum size smaller than the actual drum diameter, the shoe w ill touch the drum in its center. The ends of the shoe or the toe and the heel w ill have some clearance. When a shoe is held tightly against the drum in the middle, a .005" feeler gauge should go between the drum and each end of the lining segment. If a .005" ^ feeler gauge w ill not slide between the end sho^B and the drum, the abrasive cloth on the Grinder should be replaced. If the shoes are for a vehicle having a Duo servo brake, the anchor pin determines how the rear or secondary shoe fits the drum. Obtain the anchor pin location for the Grinder by referring to a chart provided with the Grinder. Depending on the model number of the Grinder, gauge sleeves or gauge plates w ill be used to position an anchor pin on the Grinder in the same relative position as the anchor pin on the vehicle. O nly grind enough material from the brake lining to insure proper f it of the shoe to the drum and to the anchor pin. Check the fit of the newly ground shoe in the drum. A. .0 0 5 " feeler gauge should slide easily between the ends of the shoe and the drum. Step No, 24 -- Install a ll the Brake Shoes. Correctly install a ll of the brake shoes on to the F igure 24 -- R oiete s ta r w heel u n til gauge ju st s lid e s by center of brake shoes. backing plates. Be sure that the springs are in stalled correctly. U sually the primary shoe return spring is installed on the anchor pin firs t. X Step IMo. 25 -- Adjust the Anchor Pins. If the brake design has adjustable anchor pin, adjust the anchor pin to center the shoes to the drum. Ol 56 F igure 25 -- C le a n drum s w rth a lc o h o l. 12 Step No, 26 - Adjust the Brake Shoe to Drum Clej Use a gauge to adjust drum to shoe clearance all brakes. Insert the gauge into the drum and adjust the inside caliper part of the gauge to the drum diameter. Put the outside caliper part of the gauge at the center of the shoe and horizontal to the floor. # Expand the star wheel until the shoes just touch the gauge. The gauge is designed to automatically provide a drum-to-brakeshoe clearance of .010". Step No, 27 - Clean the Drums. Wash the drums with clean alcohol to remove any trace of metal dust produced in the turn ing process. Also remove finger marks on the brake lining with clean alcohol. ^^p te p No. 28 -- Pack the Front Wheel Bearings. Pack the front wheel bearings with a good quality wheel bearing grease. A wheel bearing packer performs th e job efficiently and quickly. Install two new seals in the front wheel hubs. F ig u re 26 -- Repack w heel b ea rin g w ith pressure packer. Use a seal installer to properly seat the seal into the hub. Wipe a light film of grease on the front wheel spindle to a llow the inner race o f the wheel bearings to turn in respect to the spindle. Step No. 29 -- Install all Pour Drums. F igure 27 -- U se a p re ssure B leeder lo force b ra ke flu id to a ll th e w heel c y lin d e rs . F ig u re 28 - Use a breeder hose a n d b o t t le to c o n d u c t ar> e ffic ie n t and c le a n brake system b le e d in g jo b. Some vehicles have left-hand wheel studs on the left side of the vehicle and right-hand studs on the right side of the vehicle. Care must be taken in order that the correct front hub is placed on the proper side of the vehicle. Step No. 30 -- Bleed the H ydraulic System. Check the pressure Bleeder to see if it has enough brake fluid in it to perform the job. Some bleeder designs, especially those that connect to a tire to obtain the bleeding pressure, must be purged of the a ir that was induced into the bleed er when the bleeder was checked for fluid level. To accomplish this, squirt flu id into the master cylinder reservoir or the bleeder bottle until a solid stream of fluid results. Screw the proper adaptor to the top of the master cylinder reservoir. Check alt wheel cylinder bleeder valvesr-to make sure that they are closed. Connect the bleeder connector to the adaptor. Using a bleeder hose and b o ttle , bleed the left front cylinder until the 13 i F igure 2 8 A -- Brake Road T e st. P e rio d ic V e h ic le M a in te n a n ce In s p e c tio n Program s are b e in g developed in m any s ta te s th ro u g h o u t the U n ite d S ta tes. One o f the Brake Test M ethods em ployed in P .V .M .L P rogram s in v o lv e s the use o f a D e celerom e te r a s show n above. entering fluid makes no bubbles in the bottle. Then bleed the right A front cylinder, then the le ft rear and fin ally the right rear. D is c o n n e c t the bleeder hose from the master cylinder adaptor, remove the adaptor and replace master cylinder cap. Step No. 31 -- Put on the Wheels. Install the wheel nuts in a manner that w ill not distort the brake drum. Step No. 32 -- Check Brake Pedal Height, After a complete brake job the car should be delivered to the owner, having a hard pedal and a stroke equal to at least one-half of the brake pedal travel that is available. If the pedal is low or spongy, the master cylinder probably needs rebuilding. X Step No. 33 -- Connect and Adjust the Parking 8rake System. When the parking brake pedal or handle is applied approximately 1 / of it's total travel both rear wheels should have the same resistance to turning or be locked. When the brake is released, the rear wheels should turn freely. Step No. 34 ~ Remove the Vehicle from the Stands or Hoists. Step No. 35 - Road Test the Vehicle. 14 0157 HOW to perform the COMPLETE brake job DISC BRAKE SECTION . HOW TO PERFORM THE COMPLETE DISC BRAKE JOB Figure 29 - Support the car on a hoist or jack stands. Mark a hub stud and its corresponding hole in the wheel to retain the wheel balance. t Figure 30 - Place the wheel, outer sidewall down I on the floor. Put the hub cap inside the wheel. Put the brake parts into hub cap. Mark the Brake Disc L or R. 16 8 S LO V i i Figure 33 - Mark the location of each Disc Brake Shoe on rear of the shoe. Disc Brake Shoes wear thinner at one end than the other. The leading edge of the shoe ears more than the trailing edge 1 fusing the shoe to be tapered, ."he shoes are to be reused, must be marked and replaced ,1 in the same position as removed: otherwise, brake problems can result. 1 Figure 34 - After the shoes are removed from the caliper, the pistons are pushed into their cylinder bores by prying against the Brake Disc, if the pistons do not move freely, the caliper must be overhauled. X Figure 35 - Use hydraulic pressure, created by pushing on the brake pedal, to force the pistons out of their bores. A cover should be placed over the chi per to keep brake fluid from squirting 0 onto the car. The pistons normally w ill not como completely out of -1 their bores unless the Disc has been worn beyond factory specifica 1001 tions. Additional fluid may have to be added to the master cylinder reservoir in order to push the pistons out against the face of the Brake Disc. 18 lY liiftifriili\m k'H hrflilhliln # Figure 36 -- The pistons are nearly out of their caliper bores. Now repeat steps shown in Figs. 29 thru 36 on the right front wheel. Then remove the rear brake drums and turn the drum having the largest diameter or which is most deeply scored on the Drum Lathe. Figure 38 -- Remove caliper bridge bolts. These are special heat Sated bolts. Do not substitute r bolts if the caliper bridge s are defective. 19 Figure 39 -- Use an Outside Micrometer to determine if the Brake Disc has worn beyond manufacturers specifications. Also, check the Disc for thick ness variation by measuring the Disc in three or more places about its circumference, about 1" in from outside circumference of the Disc. Figure 40 -- Install a Dial Indicator on the spindle. Locate the Indicator Anvil about 1" in from outer circumference of the Disc. Rotate the Disc slowly. Notice the maximum total indicated reading of the Indicator. If the T.I.R. i ^ . greater than factory ) specifications, the wheel bearing should be adjusted to specifications with a Torque Wrench. Determine whether the Disc should be resurfaced, reconditioned or replaced by the overall appearance of the Disc. X Figure 41 - Remove spindle nut safety washer and outer bearing cone. Screw on the spindle nut a few turns. Using the spindle nut as a stop, pull the Disc off the spindle sharply. This action w ill remove the inner bearing and seal from the hub. Inspect the bearing races thoroughly for pits and nicks. 20 0160 Figure 43 -- Do not drive the outer race into hub with a punch as the outer edge of the cup may be damaged. Drive cup flush with the hub face using a soft brass drift. f ig u r e 44 -- After both rear drums have been machined, install the Disc Brake Tool Bar on cross slide. Figure 45 -- Mount Brake Disc a l" arbor with the Brake Adaptors. These tors seat against the of the lathe arbor and the edge of the bearing cup. 2 oi 61 Figure 46 -- Securely tighten arbor nut to {irmly seat bearing cups. Addi tional 1" arbor spacers may be required if both inner and outer bearing cups are being pressed into the hub. Figure 47 -- Adjust the tool bar to conform to the Disc by sliding bar in tool holder. The outer edge of the Disc should just Clear the tool holder. ) Figure 49 -- Bring the tool bit point against Disc at either the ' extreme inner diameter or maximum outer diameter. Let the tool bit lightly scratch the surface of the Disc as the D isc revolves. This position w ill be used as a starting reference point to determine the depth of cut. Figure 50 -- Mark the position of the scratch cut on Depth* Of-Cut D ial at the end of the lathe with a piece of chalk. Move cross slide with the hand wheel inward across face of Oise. Determine visually the deepest score in the Disc face. Turn the Infimatic Feed Handle clockwise until the toot is at the bottom of the pest groove. Notice number of marks that the Depth-Of-Cut Dial has moved from-the first Chalk mark. This determines the depth of the groove and indicates the amount that w ill have to be removed from the face of the Disc. Figure 51 - Back the tool bit out of the deepest groove. Turn the cross slide hand wheel until the tool bit is a t the smallest diameter of the Disc face. Turn the Depth-Of-Cut Hand Wheel {Infimatic Feed Handle) clockwise until the Depth-Of-Cut D ia l has gone two marks or .004" beyond the deepest scratch cut mark. Lock the lead screw lock nut. If the lathe has a lead screw lock ring, rotate it to lock the lead screw. Figure 52 -- Engage the Disc Brake Feed Mechanism by pulling the handle toward the machine. This w ill machine the D isc at the fast feed or .0 1 0 ' travel across the face of the Disc for each revolution of the lathe. Pushing the red knob away from the machine w ill turn the D isc at a slow feed or .0 0 2' travel across the face of the Disc for each revolution of the lathe. Figure 53 * The finish of the machined surface of X the Disc w ill not be ac ceptable if the fast feed is used. A Disc Brake o Grinder is then used to make the surface non _1 d irecti ona I or remove the 0) tool marks. The Disc N) Brake Grinder also pro vides an acceptable micro finish to the Disc face. i^ 'U n d ifiM U Iltjiu iin M ;r 0 Figure 54 - W hile the Disc is being machined, the caliper may be rebuilt. F irst remove the boots from th eir retainers. Later model calipers require that the pistons be removed before the boots. Figure 55 -- Identify each piston as to the caliper bore from which it was removed. I lure 56 -- Clamp outside half caliper in a v is e . Caution should be taken so that a critical area of the calip er is not damaged by the vise jaw s. Remove and mark the pistons. 25 0163 Figure 58 -- Visually inspect the seal retainers for nicks or burrs. Replace the retainer by prying the retainer from the boss of the c aliper. Later model calipers do not have a separate retainer. The retainer is part Of the caliper. Figure 59 -- Replace the boot retainer by using a special tool or use a round hardwood block or m allet head to seat the retainer on the boss. Figure 60 - Use an electric d rill and inspection hone to clean up the cylinder w alls. Alcohol may be used as honing fluid. How ever, brake fluid could also be used. X Figure 61 -- Clean the caliper cylinder bores with a clean shop cloth and alcohol. 26 . tu - a lf e O M tU *. jL u . Figure 62 -- Install the new piston seals into grooves of cylinder bore. Figure 63 -- Lubricate the wheel cylinder piston with brake fluid or wheel cylinder assembly fluid. Push piston into cylinder bore slowly being careful not to force the seal out of its groove. Figure 64 - Install the new iliper piston boot. The large ameter of the seal fits around the seal retainer. The inner diameter of the seal fits into a groove in the outer edge of the piston. Later model calipers require that the boot and piston be installed at the same time. Figure 65 - Use fine emory cloth or 400 wet-or-dry paper to clean he mating surfaces of the er. Do not use a file . The ing surface must be accurate; otherwise, the calip er could be distorted when it is bolted together. 27 Figure 66 -- Pack the wheel bearings with a good quality wheel bearing grease. Use a wheel bearing packer to insure that the grease is forced throughout the bearings. Figure 67 -- Use a Torque Wrench to properly seat the bearing cups and force the new grease out of the bearing. This provides for an accurate adjustment of the bearings. Tighten the spindle nut to a torque of 30 f t. lbs. Then back off the spindle nut until the Disc is loose on the spindle. Then tighten the spindle nut finger tight. Replace the cotter key. Figure 68 -- Install the outer section of the c a lip e r to the inner sec tion with the caliper bridge bolts, Refer to the car factory specifi cations for the torque required to tighten the caliper bridge bolts. Tighten flare nuts on cross-over-tube with suitable wrench. Z Figure 6 9 -- Obtain the correct Disc Brake Shoe by using the F .M .S .I. (Friction Material Stand ard Institute) Number Identifica tion. The F.M .S.I. Number of this shoe is S-728. If the old shoes are going to be reused, be sure to install the shoes In their former location. Ol 64 o Figure 70 - Install the splash shield correctly or the wheel may scrape on it. Figure 71 -- Install the proper Single or Dual Master Cylinder Bleeder Adaptor. Observe the warning caution on the cover stating that a special Disc Brake Fluid must be used. of pressure. Open the Bleeder Valve on the Master Cylinder firs t, then bleed the LF, RF, I.R and fin ally the RR Brake Assembly. Install the wheels. Apply the brake pedal a few times to insure proper brake operation before the car is moved. 29 i DIAGNOSING BRAKE PROBLEMS When a customer brings his car to the repair shop for Brake Service he probably has experienced a change in the operation of his car's brakes. There are a number of solutions to each particular Brake problem. The following list will outline a number of causes and fixes for each typical customer complaint. The brake problems covered occur when the brakes are applied. LOW. HARD BRAKE PEDAL Power Brake Unit not operating. Before replacing Unit check vacuum Excessive drum to brake shoe clearance. Self-adjusting brakes not working. Seif-adjusting brake parts corroded or bent. Thin, glazed cracked brake lining. Polished, glazed brake drum. Dual master cylinder system has lost the fluid in either the front or rear brakes. Improperly adjusted parking brake. Minor adjustment or brake reline is required. Inform the customer how the self-adjusting brake works. Lubricate star wheel. Replace brake operating lever if bent. Replace brake lining. Machine brake drum on a lathe. Repair warning light bulb. Repair hydraulic system. Readjust parking brake. LOW. SOFT SPONGY BRAKE PEDAL A ir in hydraulic system. RefiH master cylinder. Bleed system. Defective residual check valve in master cylinder. Rebuild or replace master cylinder. L o w or nearly empty master cylinder. Find leak in system and bleed brakes. D efective brake hose. Unground or improperly ground brake shoes. Replace brake hose and flush hydraulic system. Regrind brake shoes to anchor and drum. Oversize brake drums, Repl ace brake drums. incorrect anchor pin adjustment. Perform anchor pin adjustment. X Ridges on d is c faces. Machine or replace disc. HIGH, HARD BRAKE PEDAL Brake pedal push rod too long. Adjust push rod to master cylinder piston clearance. Self-adjusting brakes over-adjusting. Consult car diiver as to his use ofI Use a brake shoe adjusting tool t< correctly preadjust the shoe to drum clearance. H ard, g lazed brake lining. Replace brake lining. Low Iric tio n brake lining. Replace brake lining. D is c brake caliper piston frozen. Replace or rebuild caliper. Power brake unit not w orking. Replace power unit and readjust brake shoe to drum clearance. Ol 65 BRAKE PEDAL PULSATION i ^ o rte d drum or disc. Correctly install the wheel to the brake Out-of-round drum. drum hub or disc. Turn d-um on brake lathe. Not concentric drum, "wobbling" drum. Turn drum on brake lathe with correct adaptors. Brake disc has excessive runout. Turn disc on brake lathe with disc brake adaptors. Brake disc has variable thickness. Turn disc on brake lathe with disc brake adaptors. POWER BRAKE PEDAL DOES NOT DROP AS ENGINE IS STARTED Reserve vacuum was not depleted from tank. Pump brake pedal 5 times with engine "off" before testing brakes. No vacuum to power brake unit. Defective check valve. Collapsed vacuum hose. ir unit defective. Replace power brake unit. CAR PULLS TO ONE SIDE AS BRAKES ARE APPLIED Frozen wheel cylinder piston Rebuild or replace wheel cylinder. Restricted brake tube or hose Replace brake tube or hose. Brake shoes reversed or both sec Install brake shoes correctly. ondary shoes are on one side of car. Grease or brake fluid on the brake lining. Replace or rebuild wheel cylinders. Replace axle seal. Brake shoe springs improperly installed. Clean springs and install according to color. Brake shoes springs stretched or overheated. Replace springs on all brake assemblies. Brake shoes improperly ground. Grind brake shoes to match drum diameter. Loose wheel bearing. Adjust wheel bearing correctly. Vehicle out-of-alignment. Realign vehicle. V^fo steering parts. Replace idler arm. tie rod etc. 3 1 tire pressure or tire size. Match tire size and properly inflate tires. DRAGGING BRAKES Frozen wheel cylinder pistons. Replace or rebuild wheel Cylinder. Stretched or fatigued shoe return springs. Replace shoe return springs. Master cylinder compensating port closed. Adjust master cylinder push rod clearance or free play. Disc brake master cylinder.has check valve in line to disc brakes. Rebuild or replace master cylinder without a static check valve. Roar wheel parking brake cables Frozen. Replace or lubricate the parking brake cables. Minor brake adjustment too tight. Back-olf star wheel at least 10 clicks. BRAKE SQUEAK OR SQUEAL D irt embedded into lining. Remove dirt from brake assembly and drum. Qlazed, cracked brake lining, Grind brake shoes or replace brake. polished brake drums, Turn brake drums. d. overheated brake shoe Replace springs. springs. V* H | BRAKE CHATTER Grease or brake fluid on brake iining. Brake shoes ground incorrectly. Replace brake shoes. Ground brake shoes should have .005 to .0 0 8 thousandths heel and toe cl earance. Loose backing plates. Excessive rear axle endplay. Tighten backing plate bolts. Adjust rear axfe bearings to manufacturer's specifications. 31 oiLiiti. AMAUCO Tools, Inc. REGIONAL MANAGERS WEST COAST REGION ANDREW BROWN 13075 Sunset Boulevard Los Angeles, California 213/476-3620 90049 NORTH CENTRAL REGION KENNETH N. WOOD 2025 E. 110th Street Indianapolis. Indiana 317/846-5581 W 46280 MIDWEST REGION LARRY L. MONTEITH 3265 Robin Crest Drive Northbrook, Illin o is 60062 312/272-6174 NORTHEAST REGION JOHN R. DRAGONI 148 County Road Ipswich, Mass. 01938 617/356-3263 SOUTHWEST REGION FRANK VAN PARYS 3375 Valiant Drive Dallas Texas 75229 214/357-9934 SOUTHEAST REGION ALBERT S. GOODGAME 1311 Swims Valley D r., N.W. A tlan ta, Georgia 30327 404/255-3358 Ol 66 I IR A K E SERVICE equipment NO. 40 BRAKE SHOP Includes Brake Lathe for machining brake drums and disc brake rotors and Brake Shoe Grinder to grind brake shoes to an arc 10 m atch the drums. Lathe design permits switching from drums to discs in a fe w seconds. Units mounted on mobile bench for easy portability. NO. 7750 BRAKE DISC FACING SET Permits fa s t accurate machining of disc brake rotors. Can be installed on any M odel 3 0 0 0 Brake Drum Lathe. This set included in No. 4 0 Brake Shop. MODEL 8350 ''SAFE-SW IRL" DISC BRAKE ROTOR GRINDER Used w ith Drum Lathe to provide non-directionai swirl finish required by most factory specs. M O D EL 9 0 0 0 BRAKE D R U M LATHE Turns 6" to 1 6 Mdia. drums. Infinitely variable feed permits ^ adjustments from .001" to .015*. This allows maximum cutting capacity for roughing and finishing. (Shown on No. 9400 Stand.) 4 MODEL 8000 BRAKE SHOE GRINDER Assures correct arc of brake shoes to match the drum. Fast, automatically accurate.