| Master cylinders manufactured by ATE, Girling and | | | | wheel and tire and disconnect hydraulic line, |
| Bendix utilize 2 or 3-chamber reservoirs, a level | | | | remove caliper and disc and turn the rear axle |
| sensor contact is built into each chamber.A | | | | flange until the threaded hole faces down, |
| warning light is activated when brake fluid level is | | | | compress spring with spring and turn 90 |
| low or when pressure differential between two | | | | degrees.2. Remove all retainers and hold-down |
| brake circuits is caused by loss of fluid in either | | | | springs, detach lower return spring opposite |
| circuit.Floating type front disc brake calipers are | | | | adjuster and pull brake shoes apart enough to |
| used on the 190, 420 and 560 series; Not floating | | | | remove over rear axle shaft flange, detach upper |
| type calipers on other models with parking brakes | | | | return spring and remove adjuster. |
| are cable-actuated in rear brake rotor calipers.All | | | | Cleaning & Inspection Use brake vacuum cleaner |
| models have brake pad wear indicators and | | | | to clear asbestos dust from assembly and check |
| differential pressure warning indicator.Wear | | | | condition of linings and components.Disc brake |
| sensors for 420 and 560 series operates on inner | | | | rotor inside diameter is 160 m.m. parking brake |
| pads only.The Anti-Lock Brake System is | | | | lining width 25 m.m..Installation1. To install reverse |
| standard on 420SEL, 300 and 560 series (optional | | | | procedure, lubricate all adjuster components and |
| on 190 series). | | | | sliding surfaces of backing plate with silicone brake |
| On diesel models, a vacuum pump is incorporated | | | | grease.2. Return adjuster to position and install on |
| to supply a vacuum to the power brake | | | | shoes with adjusting wheel facing 45 degrees |
| unit.ADJUSTMENTS PEDAL HEIGHT & FREE | | | | forward diagonal swing axle or 90 degrees |
| PLAYPedal height measured from pedal pad to | | | | forward diagonal swing axle with starting torque |
| pedal stop should be 150 m.m. | | | | compensation.3. Attach hold down springs and |
| to adjust loosen lock nuts and turn stop light | | | | retainers and return springs, install disc and adjust |
| switch until correct pedal height is obtained tighten | | | | parking brake.SINGLE DIAPHRAGM & PISTON |
| lock nuts; pedal free play should be 5-15 | | | | TYPE VACUUM PUMPRemoval Diesel Only While |
| m.m..BRAKE LIGHT SWITCH | | | | holding lock nuts loosen vacuum lines from pump, |
| The stoplight switch is located under dash, above | | | | detach hex head mount screws from crankcase |
| brake pedal loosen lock nuts and adjust switch so | | | | and remove vacuum pump and gasket.Piston |
| that contact button extends 6-8 m.m. then | | | | type vacuum pump screw connector is provided |
| tighten lock nuts.PARKING BRAKE | | | | with oil retention valve, when pump is stopped |
| 1. Remove only one wheel lug bolt at each rear | | | | and vacuum is available, valve prevents engine oil |
| wheel, raise vehicle.2. Rotate wheel until lug bolt | | | | from entering power brake unit.Installation Install |
| hole is positioned over parking brake adjuster, | | | | vacuum pump with new gasket to crankcase, the |
| approximately 45 degrees forward for diagonal | | | | new gasket thickness is 2 m.m. Connect vacuum |
| swing axle and 90 degrees forward for diagonal | | | | lines and test for proper operation.DOUBLE |
| swing axle with starting torque | | | | DIAPHRAGM VACUUM PUMP (Diesel Only)1. |
| compensation.ADJUSTING PARKING BRAKE | | | | Loosen upper radiator hose and drain some |
| MECHANISM | | | | coolant and remove the fan radiator shell and |
| Parking brake must be adjusted if brake pedal | | | | power steering pump belt.2. Loosen vacuum lines |
| can be depressed by more than 2 steps of 6 | | | | from pump; remove hex head mount screws |
| without any braking effect, do not alter adjusting | | | | from crankcase remove vacuum pump with |
| screw on parking brake intermediate lever; these | | | | toothed intermediate sleeve and |
| screws are for balancing cable lengths only.3. Using | | | | gasket.Installation1. Clean sealing surfaces and |
| screwdriver inserted through lug bolt whole hand | | | | install pump with new gasket to crankcase and |
| turn adjuster until rear wheel cannot be turned, | | | | ensure intermediate sleeve and pump locating pins |
| back off the adjuster until wheel can be turned | | | | are properly seated in crankcase.2. Connect |
| without wheel dragging.TESTING THE BRAKE | | | | vacuum lines to pump, install belt radiator shell, fan |
| WARNING LIGHT | | | | and hose, check pump for proper |
| 1. Dual warning light is mounted on dash, turn | | | | operation.OVERHAUL FRONT DISC BRAKE |
| ignition on and the light should glow when parking | | | | CALIPERSDisassembly 420SEL, 300 & 560 |
| brake lever is pulled to one notch and go off | | | | SeriesRemove caliper from vehicle and place piece |
| when brake lever is fully released.2. To check | | | | of wood in front of piston, gradually apply |
| circuit warning sensor, turn ignition on, release the | | | | compressed air into fluid inlet remove piston and |
| parking brake and ensure light is off, | | | | remove dust boot from piston and piston seal |
| Open bleeder screw on one wheel and depress | | | | from caliper bore.Cleaning & Inspection1. Wash |
| brake pedal and the light should light up.3. Close | | | | parts in alcohol or brake fluid and air dry, inspect |
| bleeder screw, replenish the brake fluid and bleed | | | | caliper bore and piston for scoring scratches or |
| system, check that light goes out after testing | | | | rust, standard front brake caliper bore inside |
| and if not; differential pressure pin in the master | | | | diameter is 60 m.m..2. Replace dust boot and |
| cylinder must be reset.REMOVAL & | | | | piston seal when disassembling caliper, remove |
| INSTALLATION OF DISC BRAKE PADSRemoval | | | | small rust deposits in bore with fine cloth.When |
| 420SEL, 300 & 560 Series1. Raise vehicle and | | | | installing new caliper and check that calipers on |
| remove wheels, remove upper hex head caliper | | | | same axle have pistons of same diameter, only |
| bolt.2. Pull clip of the brake pad wear sensor out | | | | identical calipers should be installed on front |
| of plug by opening cap on plug, rotate caliper | | | | axle.Reassembly Coat piston and caliper bore with |
| downward and remove pads from carrier.3. | | | | ATE brake cylinder paste, install piston seal into |
| Standard front disc brake pad assembly thickness | | | | caliper bore and install piston and dust |
| including lining backing plate is 17.5 m.m. Standard | | | | boot.Disassembly 190, 300E, 300SDL & 420SEL |
| rear pad assembly thickness is 15.5 m.m..4. Front | | | | this procedure also applies to all rear calipers.1. |
| backing plate thickness is 4.5 m.m. Rear backing | | | | Remove caliper from vehicle and remove disc |
| plate thickness is 5mm Minimum pad thickness is | | | | pads from caliper and remove dust boot.2. Hold |
| 2 m.m..Mercedes Benz Single Piston Disc Brake | | | | one piston in place using piston Resetting Pliers, |
| Caliper cleaning.1. Using brass cylinder brush clean | | | | gradually apply compressed air to fluid inlet to |
| disc pad guide surface in caliper, siphon fluid from | | | | remove opposite piston.3. Remove piston seal |
| master cylinder to prevent overflowing press | | | | from groove of cylinder bore and remove |
| piston to bottom of bore.2. Install disc pads and | | | | remaining piston and seal in same manner. DO |
| wear sensor wires, reverse removal procedure to | | | | NOT separate caliper halves, replace only as an |
| complete installation and check that dash light | | | | assembly, calipers installed on front axle must be |
| goes out.Removal All Other Mercedes Benz | | | | from same manufacturer.Calipers on rear axle |
| Models1. Raise vehicle and remove wheels, | | | | may be different only if same brand replacement |
| remove cover plate from caliper and disconnect | | | | part is unavailable.Cleaning & Inspection1. Check |
| wear indicator wires.2. Drive out retaining pins | | | | cylinder bores of caliper for wear or damage, |
| toward inside of vehicle, on Bendix brakes | | | | small rust deposits may be removed from caliper |
| retaining pins have locking pins, then remove the | | | | bores with cloth.2. CAUTION: DO NOT clean |
| locking pins and retaining pins then the cross | | | | chrome-plated surfaces of pistons with polishing or |
| spring retainers.3. Remove disc pads from caliper, | | | | emery cloth damage to surface may |
| if not reusable note condition and location of pads | | | | result.Remove deposits with soft brass wire brush |
| for re installation.4. Standard front disc brake pad | | | | or rough cleaning cloth, replace piston if chrome |
| assembly thickness including lining backing plate is | | | | surface is damaged.2. Heavy rust deposits or |
| 17.5 m.m. Standard rear pad assembly thickness is | | | | badly scored bore will require replacement of the |
| 15 m.m..5. Front backing plate thickness is 4.5 m.m. | | | | caliper rust deposits in front of piston seal groove |
| rear backing plate thickness is 5 m.m. minimum | | | | may be removed with fine emery cloth.3. |
| pad thickness is 2 m.m..1. Using cylinder brush | | | | Standard front brake caliper bore inside diameter |
| clean disc pad guide surface in caliper, siphon fluid | | | | is 60 m.m. Standard rear caliper bore I.D. Teves is |
| from master cylinder reservoir to prevent | | | | 38 m.m. and rear caliper bore I.D Bendix Girling is |
| overflowing, press pistons to bottom.2. Mercedes | | | | 42 m.m..Reassembly1. Coat piston and caliper bore |
| Benz Disc Brake Pads.3. Install cover plate | | | | with ATE brake cylinder paste, install piston seal |
| retaining pin locking keys and wear sensor wires, | | | | into the caliper bore and then install piston.2. With |
| check that dash light goes out, and the reset pin | | | | caliper installed on the diagonal swing axle elevation |
| at master cylinder.DISC BRAKE CALIPER | | | | on the piston faces upward.On diagonal swing axle |
| REMOVAL1. Raise and support vehicle remove the | | | | with starting torque compensation, elevation on |
| wheel, open bleeder screw on caliper assembly | | | | piston must be at bottom and project at least 10 |
| and pump out fluid, disconnect and plug brake lines | | | | m.m. above shield, use DOT 4 or higher rated |
| at caliper assembly.2. Remove caliper bolts, | | | | brake fluid during the overhaul.2. Check position of |
| remove caliper assembly from vehicle.Installation | | | | piston in caliper with Piston Gauge for front or for |
| To install reverse removal procedure, tighten all | | | | rear.3. Adjust with Piston Rotating Pliers and install |
| nuts and bolts and then bleed hydraulic system | | | | dust boot, install heat shield into piston with recess |
| and check that the dash light goes out, reset pin | | | | in shield fitting into elevation of the piston.REAR |
| in master cylinder if necessary.DISC BRAKE | | | | DISC BRAKE CALIPEROverhaul procedure is the |
| ROTOR REMOVAL (Front)1. Remove caliper | | | | same as front caliper of 300E, 300SDL and |
| assembly and hub grease cap, remove contact | | | | 420SEL models.MASTER CYLINDER |
| spring for radio shielding, loosen clamping nut | | | | CAUTION:BENDIX master cylinder painted Blue |
| socket screw on wheel spindle.2. Remove | | | | cannot be overhauled and replace as an assembly |
| clamping nut and washer, remove wheel hub and | | | | only.Disassembly Tandem & Stepped Tandem1.On |
| rotor assembly, remove bolts securing hub to | | | | tandem master cylinder remove the reservoir and |
| rotor, remove rotor.Cleaning & Inspection1. Clean | | | | push piston in |
| disc and check for cracks, scoring or excessive | | | | remove stop screw; remove the push rod piston |
| wear, replace as necessary.2. Before installing | | | | assembly and O ring.2.Remove the lock ring from |
| stock replacement disc, use solvent to remove | | | | housing and remove the floating circuit piston, and |
| nitrocellulose corrosion preventive paint from rotor | | | | stop washer with two vacuum seals and |
| surface.Installation To install reverse removal, | | | | intermediate ring.3.Tap lightly on housing with |
| tighten all bolts and fittings evenly, bleed hydraulic | | | | plastic mallet to remove the floating circuit piston |
| system if necessary, lubricate and adjust wheel | | | | assembly.On Teves reservoir only remove cap |
| bearings, see appropriate article in suspension | | | | end covers and strainer and splash guard, O rings |
| section.Removal rear brakes1. Remove rear wheel | | | | and contact the inserts.On Bendix models, |
| and tire and disconnect and plug brake lines, | | | | remove strainer from cover, DO NOT remove |
| remove caliper assembly.2. Using rear axle shaft | | | | the contact inserts.Always use DOT 4 or higher |
| Assembly Tool 116 589 24 61 00, pull rotor out | | | | brake fluid during overhaul. |
| from axle shaft flange.1. To install reverse | | | | .Cleaning & Inspection1.Clean all parts with alcohol |
| procedure, coat the axle splines with high | | | | or brake fluid and flush residue out of housing, |
| temperature lubricant grease wheel bearings and | | | | check bore in housing and the piston for score |
| install seal if necessary.2. Tighten all bolts and | | | | marks and rust.2. Small rust spots in housing may |
| fittings evenly and bleed hydraulic system.REAR | | | | be removed with emery cloth scored or badly |
| AXLE SEAL Removal1. Remove rear wheel and | | | | rusted parts cannot be repaired and require |
| tire and release locking plates, remove mount | | | | replacement of complete master cylinder.3.On |
| bolts and caliper, wire caliper out of the way.2. On | | | | tandem models with standard master cylinder |
| vehicles with starting torque compensation, | | | | inside diameter is 23.81 m.m. maximum bore wear |
| disconnect brake hose holder and hang caliper | | | | limit is 23.92 m.m..4.On the stepped tandem |
| assembly with wire.3. Loosen and remove 8 m.m. | | | | models, standard master cylinder I.D. for push rod |
| bolt or 12 m.m. bolt with spacing sleeve and | | | | circuit is 23.81m.m. and I.D. for floating circuit is |
| clamping disc at center of rear brake rotor.4. | | | | 19.05 m.m..5. Maximum master cylinder bore I.D. is |
| Using rear axle shaft Assembly Tool, remove | | | | 23.92 m.m. for push rod circuit and 19.16 m.m. for |
| rotor from rear axle shaft flange and pry rear | | | | floating circuit.Reassembly1. To assemble reverse |
| axle seal from rotor at inner wheel bearing and | | | | disassembly procedure, coat the bore of master |
| discard.If the brake rotor is difficult to free from | | | | cylinder with brake fluid.2. Install new floating circuit |
| the axle flange strike the outer circumference | | | | piston assembly and push in piston assembly and |
| lightly with a plastic hammer and ensure parking | | | | install lock ring.3. Install the new push rod piston |
| brake is released.Installation1. Coat inside of new | | | | assembly and screw in stopper screw using new |
| axle seal lip and wheel bearings with grease, install | | | | copper washer for Gray iron master cylinder or |
| bearings and seal into rear brake disc.2. Coat axle | | | | new aluminum washer for light alloy master |
| splines with heat resistant lubricant and install disc, | | | | cylinder.Replace O ring to ensure proper vacuum |
| to complete installation reverse removal | | | | seal at power brake unit and bleed hydraulic |
| procedure.Mercedes Benz master cylinder | | | | system, check that the dash light is out.Differential |
| removal1. Drain master cylinder fluid and | | | | pressure warning indicator reset pin located at the |
| disconnect and plug brake lines, disconnect | | | | front end of master cylinder MUST be reset once |
| electrical wires.2. Remove the bolts securing | | | | and indicator light in dash panel has been |
| master cylinder to power brake unit and remove | | | | triggered.POWER BRAKE UNITManufacturer does |
| master cylinder.Installation1. Reverse procedure; | | | | not recommend disassembly of this unit, if |
| always replace rubber "O" ring seal between | | | | problem is found in power brake unit complete |
| master cylinder and power unit.2. Bleed hydraulic | | | | assembly must be replaced, DO NOT disassemble |
| system and check complete system for fluid | | | | power brake unit, determine whether source of |
| leaks, check that dash light is out and reset pin in | | | | problem is in power brake unit or the check valve. |
| cylinder.PARKING BRAKE LININGS1. Remove | | | | |