Файл: 92FWD_5.pdf

Fig. 8 Open Bleeder Screw at Least One Full Turn

(Typical)

Repeat the procedure at all the other remaining bleeder screws. Then check the pedal for travel. If pedal travel is excessive or has not been improved. Enough fluid has not passed through the system to expel all the trapped air. Be sure to monitor the fluid level in the pressure bleeder. It must stay at the proper level so air will not be allowed to reenter the brake system through the master cylinder.

BLEEDING WITHOUT A PRESSURE BLEEDER

If a pressure bleeder is not available. A good brake fluid flow can be obtained by manual bleeding of the brake hydraulic system, following these steps.

(1)Pump the brake pedal three or four times and hold it down before the bleeder screw is opened.

(2)Then open the bleeder screw at least 1 full turn. When the bleeder screw opens the brake pedal will drop all the way to the floor.

(3)Release the brake pedal only after the bleeder screw is closed.

(4)Repeat steps 1 through 3, four or five times, at each bleeder screw. This should pass a sufficient amount of fluid to expel all the trapped air from the brake system. Be sure to monitor the fluid level in the master cylinder, so it stays at a proper level so air will not reenter the brake system through the master cylinder.

Test drive vehicle to be sure brakes are operating correctly and that pedal is solid.

TEST FOR FLUID CONTAMINATION

Fig. 9 Wheel Stud Nut Tightening Sequence

Tighten all stud nuts to one-half specified torque. Repeat, fully tightening to 129 NIm (95 ft. lbs.).

BRAKE HOSE AND TUBING

INSPECTION OF BRAKE HOSE AND TUBING

Flexible rubber hose is used at both front brakes and at the rear axle. Inspection of brake hoses should be performed whenever the brake system is serviced and every 7,500 miles or 12 months, whichever comes first (every engine oil change). Inspect hydraulic brake hoses for severe surface cracking, scuffing, or worn spots. Should the fabric casing of the rubber hose be exposed due to cracks or abrasions in the rubber hose cover, the hose should be replaced immediately. Eventual deterioration of the hose can take place with possible burst failure. Faulty installation can cause twisting and wheel, tire or chassis interference (Figs. 10, 11 and 12).

The steel brake tubing should be inspected periodically for evidence of physical damage or contact with moving or hot components.

INSTALLATION OF BRAKE HOSE

Always use factory recommended brake hose to ensure quality, correct length and superior fatigue life. Care should be taken to make sure that the tube and hose mating surfaces are clean and free from nicks and burrs. Front right and left side hoses are not interchangeable.

Connections should be correct and properly made. Use new copper seal washers on all connections using Banjo Bolts and tighten all fittings to their specified torques.

The flexible front hydraulic brake hose should always be installed on the vehicle by first attaching the Banjo connector to the caliper assembly. Then bolt the intermediate hose bracket to the strut assembly allowing the bracket to position the hose to prevent twisting. Attach the hose to the body bracket and steel brake tubing. Tighten all fittings to specified torque. The body bracket and hose end are keyed so that they will only fit one way.

Install rear brake hoses first to the trailing arm tubes and then to the floor pan tubes. Minimize hose twisting. Vehicles equipped with rear disc brakes have brake hoses attached to the caliper on each side. The brake hose should be first attached by the Banjo bolt to the caliper and then secured to the hose bracket with the retaining clip. Then attach the steel brake tubing to the hose fitting.

REPAIR AND INSTALLATION OF BRAKE TUBING

Only double wall 4.75mm (3/16 in.) steel tubing should be used for replacement. Care should be taken when replacing brake tubing, to be sure the proper bending and flaring tools and procedures are used, to avoid kinking. Do not route the tubes against sharp edges, moving components or into hot areas. All tubes should be properly attached with recommended retaining clips.

TYPES OF TUBING FLARES

Two different tubing flares (Fig. 13) are used on 92 M.Y. vehicles. On all ABS brake systems the tubing connections made to the hydraulic assembly use an ISO flare. All other ABS brake system component, tubing connections are made using a double inverted flare. On non-ABS brake systems all component tubing connections use only the double inverted flare. No ISO flares are used.

CAUTION: ALWAYS USE THE PROPER FLARING TOOL AND PROCEDURE, FOR THE TYPE OF BRAKE SYSTEM THAT IS BEING SERVICED TO INSURE THE INTEGRITY OF THE HYDRAULIC SYSTEM.

Fig. 13 Identifying Hydraulic Brake Tubing Flares

TO REPAIR OR FLARE TUBING

Using Tubing Cutter, Special Tool C-3478-A or equivalent, cut off damaged seat or tubing (Fig. 14). Ream out any burrs or rough edges showing on inside of tubing (Fig. 15). This will make the ends of tubing square (Fig. 15) and ensure better seating of flared end tubing. PLACE TUBE NUT ON TUBING BE-

FORE FLARING THE TUBING.

Fig. 14 Cutting and Flaring of Brake Line Tubing

Fig. 15 Brake Tube Preparation For Flaring

DOUBLE INVERTED TUBING FLARES.

To make a double inverted tubing flare (Figs. 13 and 16). Open handles of Flaring Tool, Special Tool C-4047 or equivalent. Then rotate jaws of tool until the mating jaws of tubing size are centered between vertical posts on tool. Slowly close handles with tubing inserted in jaws but do not apply heavy pressure to handle as this will lock tubing in place.

Place gauge (Form A) on edge over end of brake tubing. Push tubing through jaws until end of tubing contacts the recessed notch in gauge matching the tubing size. Squeeze handles of flaring tool and lock tubing in place. Place 3/16 inch plug of gauge (A) down in end of tubing. Swing compression disc over gauge and center tapered flaring screw in recess of disc. Screw in until plug gauge has seated on jaws of flaring tool. This action has started to invert the extended end of the tubing. Remove gauge and continue to screw down until tool is firmly seated in tubing. Remove tubing from flaring tool and inspect seat. Refer to routing diagrams (Figs. 10 to 12) for proper routing and clip location. Replace any damaged tube routing clips.

ISO TUBING FLARES

CAUTION: All ISO style tubing flares (Figs. 13 and 16) are of metric dimensions. When performing any service procedures on vehicles using ISO style tubing flares, metric size tubing of 4.75 mm MUST be used with metric ISO tube flaring equipment.

Fig. 16 Double Flare And ISO-Flare Tubing Connec-

tions

sure to place the tubing nut on the tube before flaring the tubing.

(1)Carefully prepare the end of the tubing to be flared. Be sure the end of the tubing to be flared is square and all burrs on the inside of the tubing are removed (Fig. 15). This preparation is essential to obtain the correct form of a (metric) ISO tubing flare.

(2)Open the jaws of the Flaring Tool. Align the mating size jaws of the flaring tool around the size of the tubing to be flared. Close the jaws of the Flaring Tool around the tubing to keep it from sliding out of the flaring tool, but do not lock the tubing in place. (See Fig. 17.)

(3)Position the tubing in the jaws of the Flaring Tool so that it is flush with the top surface of the flaring tool bar assembly. (See Fig. 17.)

(4)Install the correct size adaptor for the brake tubing being flared, on the feed screw of the yoke assembly. Center the yoke and adapter over the end of the tubing. Apply lubricant to the adapter area that contacts brake tubing. Making sure the adapter pilot is fully inserted in the end of the brake tubing. Screw in the feed screw of the yoke assembly until the adaptor has seated squarely on the surface of the bar assembly (Fig. 17). This process has created the (metric) ISO tubing flare.

STOP LAMP SWITCH ADJUSTMENT (ALL VEHICLES)

To create a (metric) ISO style tubing flare, Use Snap-On Flaring Tool TFM-428, or equivalent. See (Fig. 17) and proceed with the steps listed below. Be

The stop lamp switch incorporates a self adjusting feature. If adjustment or replacement is required, proceed as follows: Install the switch in the retaining

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Fig. 17 ISO Tubing Flare Process

bracket and push the switch forward as far as it will go. The brake pedal will move forward slightly (Fig. 18). Gently pull back on the brake pedal bringing the striker back toward the switch until the brake pedal

BRAKES 5 - 13

Fig. 18 Stop Lamp Switch

will go back no further. This will cause the switch to ratchet backward to the correct position. Very little movement is required, and no further adjustment is necessary.