Drum Brakes

Introduction

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Rear drum brake assembled view— F-250 HD and F-350

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Rear drum brake exploded view— F-250 HD and F-350

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Brake Drums

REMOVAL & INSTALLATION

F-150, F-250 and Expedition Models

Lift the brake drum from the shoes and backing plate

Raise and safely support the vehicle securely on jackstands.
Remove the tire and wheel assembly.
Remove the three retaining clips (if equipped) and remove the brake drum.

It may be necessary to back off the brake shoe adjustment in order to remove the brake drum. This is because the drum might be grooved or worn from being in service for an extended period of time.

Before installing a new brake drum, be sure to remove any protective coating with brake cleaner or a suitable fast-drying degreaser.

Install the brake drum in the reverse order of removal and adjust the brakes.

1997-98 F-250HD and F-350 Models

Brake drum assembly—1997-98 F-250HD and F-350

Raise the vehicle and install jackstands.
Remove the tire and wheel assembly.
Loosen the rear brake shoe adjustment.
Remove the rear axle retaining bolts and lockwashers, axle shaft, and gasket.
Remove the wheel bearing lock-nut, lockwasher, and adjusting nut.
Remove the hub and drum assembly from the axle.
Remove the brake drum-to-hub retaining screws, bolts or bolts and nut. Remove the brake drum from the hub.

To install:

Place the drum on the hub and attach it to the hub with the attaching nuts and bolts.
Place the hub and drum assembly on the axle and start the adjusting nut.
Adjust the wheel bearing nut and install the wheel bearing lockwasher and lock-nut.
Install the axle shaft with a new gasket and install the axle retaining bolts and lockwashers.
Install the wheel and adjust the brake shoes. Remove the jackstands and lower the vehicle.

INSPECTION

Measure the drum using a micrometer especially for drums

Brake drum maximum diameter location

Check that there are no cracks or chips in the braking surface. Excessive bluing indicates overheating and a replacement drum is needed. The drum can be machined to remove minor damage and to establish a rounded braking surface on a warped drum. Never exceed the maximum oversize of the drum when machining the braking surface.

The brake drum inside diameter and run-out can be measured using a brake drum micrometer. The drum should be measured every time a brake inspection is performed. Take the inside diameter readings at points 90° apart from each other on the drum to measure the run-out. The maximum inside diameter is stamped on the rim of the drum or on the inside above the lug nut stud holes and is also contained in the brake specifications chart at the end of this section.

Brake Shoes

INSPECTION

Measure brake shoe thickness in several places around the shoe

Inspect the brake shoes for wear using a ruler or Vernier caliper. Compare measurements to the brake specifications chart. If the lining is thinner than specification or there is evidence of the lining being contaminated by brake fluid or oil, repair the leak and replace all brake shoe assemblies (a complete axle set). In addition to the shoes inspect all springs and brake shoe hardware for wear and replace as necessary.

REMOVAL & INSTALLATION

F-150, F-250 and Expedition Models

Remove the brake shoe retracting springs ...

... from both sides

Rotate the hold down spring retainer and ...

... remove the hold down spring from the primary brake shoe

Remove the primary shoe and unhook the adjusting spring from the shoe

Remove the adjusting screw

Remove the brake shoe adjusting lever cable

Remove the adjusting spring

Remove the adjusting lever return spring

Remove the anchor pin guide plate

Remove the parking brake strut

Remove the secondary shoe hold down spring and ...

Lift the secondary shoe from the backing plate

Remove the parking brake lever horseshoe clip apart and ...

... remove the washer from under the horseshoe clip and ...

... remove the secondary brake shoe from the parking brake lever

Thoroughly clean and ...

... lubricate the ...

... shoe contact points on the backing plate

Raise and safely support the vehicle securely on jackstands.

When servicing drum brakes, only dissemble and assemble one side at a time, leaving the remaining side intact for reference.

CAUTION

Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with the eyes and wash your hands thoroughly after handling brake fluid. If you do get brake fluid in your eyes, flush your eyes with clean, running water for 15 minutes. If eye irritation persists, or if you have taken brake fluid internally, IMMEDIATELY seek medical assistance.

Contract the brake shoes by pulling the self-adjusting lever away from the starwheel adjustment screw and turn the starwheel up and back until the pivot nut is drawn onto the starwheel as far as it will come.
Pull the adjusting lever, cable and automatic adjuster spring down and toward the rear to unhook the pivot hook from the large hole in the secondary shoe web. Do not attempt to pry the pivot hook from the hole.
Remove the automatic adjuster spring and the adjusting lever.
Remove the secondary shoe-to-anchor spring. Remove the primary shoe-to-anchor spring and unhook the cable anchor. Remove the anchor pin plate.
Remove the cable guide from the secondary shoe.
Remove the shoe hold-down springs, shoes, adjusting screw, pivot nut, and socket. Note the color of each hold-down spring for assembly. To remove the hold-down springs, reach behind the brake backing plate and place one finger on the end of one of the brake hold-down spring mounting pins. Using a pair of pliers, grasp the washer type retainer on top of the hold-down spring that corresponds to the pin which you are holding. Push down on the pliers and turn them 90° to align the slot in the washer with the head on the spring mounting pin. Remove the spring and washer retainer and repeat this operation on the hold down spring on the other shoe.
Remove the parking brake link and spring. Disconnect the parking brake cable from the parking brake lever.
After removing the rear brake secondary shoe, disassemble the parking brake lever from the shoe by removing the retaining clip and spring washer.

To install:

Assemble the parking brake lever to the secondary shoe and secure it with the spring washer and retaining clip.
Apply a light coating of Lubriplate®, or equivalent, at the points where the brake shoes contact the backing plate.
Position the brake shoes on the backing plate, and install the hold-down spring pins, springs, and spring washer type retainers. On the rear brake, install the parking brake link, spring and washer. Connect the parking brake cable to the parking brake lever.
Install the anchor pin plate, and place the cable anchor over the anchor pin with the crimped side toward the backing plate.
Install the primary shoe-to-anchor spring with the brake tool.
Install the cable guide on the secondary shoe web with the flanged holes fitted into the hole in the secondary shoe web. Thread the cable around the cable guide groove.
Install the secondary shoe-to-anchor (long) spring. Be sure that the cable end is not cocked or binding on the anchor pin when installed. All of the parts should be flat on the anchor pin. Remove the wheel cylinder piston clamp.
Apply Lubriplate®, or equivalent, to the threads and the socket end of the adjusting starwheel screw. Turn the adjusting screw into the adjusting pivot nut to the limit of the threads and then back off ¹/₂ turn.

Interchanging the brake shoe adjusting screw assemblies from one side of the vehicle to the other would cause the brake shoes to retract rather than expand each time the automatic adjusting mechanism is operated. To prevent this, the socket end of the adjusting screw is stamped with an "R" or an "L" for "RIGHT" or "LEFT". The adjusting pivot nuts can be distinguished by the number of lines machined around the body of the nut; one line indicates left hand nut and two lines indicate a right hand nut.

Place the adjusting socket on the screw and install this assembly between the shoe ends with the adjusting screw nearest to the secondary shoe.
Place the cable hook into the hole in the adjusting lever from the backing plate side. The adjusting levers are stamped with an R (right) or a L (left) to indicate their installation on the right or left hand brake assembly.
Position the hooked end of the adjuster spring in the primary shoe web and connect the loop end of the spring to the adjuster lever hole.
Pull the adjuster lever, cable and automatic adjuster spring down toward the rear to engage the pivot hook in the large hole in the secondary shoe web.
After installation, check the action of the adjuster by pulling the section of the cable guide and the adjusting lever toward the secondary shoe web far enough to lift the lever past a tooth on the adjusting screw starwheel. The lever should snap into position behind the next tooth, and release of the cable should cause the adjuster spring to return the lever to its original position. This return action of the lever will turn the adjusting screw starwheel one tooth. The lever should contact the adjusting screw starwheel one tooth above the centerline of the adjusting screw.

If the automatic adjusting mechanism does not perform properly, check the following:

Check the cable and fittings. The cable ends should fill or extend slightly beyond the crimped section of the fittings. If this is not the case, replace the cable.
Check the cable guide for damage. The cable groove should be parallel to the shoe web, and the body of the guide should lie flat against the web. Replace the cable guide if this is not so.
Check the pivot hook on the lever. The hook surfaces should be square with the body on the lever for proper pivoting. Repair or replace the hook as necessary.
Make sure that the adjusting screw starwheel is properly seated in the notch in the shoe web.

1997-98 F-250 HD and F-350 Models

Rear drum brake assembled view— F-250 HD and F-350

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Rear drum brake exploded view— F-250 HD and F-350

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Raise and support the vehicle.
Remove the wheel and drum.
Remove the parking brake lever assembly retaining nut from behind the backing plate and remove the parking brake lever assembly.
Remove the adjusting cable assembly from the anchor pin, cable guide, and adjusting lever.

CAUTION

Brake shoes may contain asbestos, which has been determined to be a cancer causing agent. Never clean the brake surfaces with compressed air! Avoid inhaling any dust from any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.

Remove the brake shoe retracting springs.
Remove the brake shoe hold-down spring from each shoe.
Remove the brake shoes and adjusting screw assembly.
Disassemble the adjusting screw assembly.
Clean the ledge pads on the backing plate. Apply a light coat of Lubriplate®, or equivalent, to the ledge pads (where the brake shoes rub the backing plate).

To install:

Apply Lubriplate® to the adjusting screw assembly and the hold-down and retracting spring contacts on the brake shoes.
Install the upper retracting spring on the primary and secondary shoes and position the shoe assembly on the backing plate with the wheel cylinder pushrods in the shoe slots.
Install the brake shoe hold-down springs.
Install the brake shoe adjustment screw assembly with the slot in the head of the adjusting screw toward the primary shoe, lower retracting spring, adjusting lever spring, adjusting lever assembly, and connect the adjusting cable to the adjusting lever. Position the cable in the cable guide and install the cable anchor fitting on the anchor pin.
Install the adjusting screw assemblies in the same locations from which they were removed. Interchanging the brake shoe adjusting screws from one side of the vehicle to the other will cause the brake shoes to retract rather than expand each time the automatic adjusting mechanism is operated. To prevent incorrect installation, the socket end of each adjusting screw is stamped with an R or an L to indicate their installation on the right or left side of the vehicle. The adjusting pivot nuts can be distinguished by the number of lines machined around the body of the nut. Two lines indicate a right hand nut; one line indicates a left hand nut.
Install the parking brake assembly in the anchor pin and secure with the retaining nut behind the backing plate.
Adjust the brakes before installing the brake drums and wheels. Install the brake drums and wheels.
Lower the vehicle and road test the brakes. New brakes may pull to one side or the other before they are seated. Continued pulling or erratic braking should not occur.

ADJUSTMENTS

Use a gauge as shown to measure the brake shoes

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Use a gauge as shown to measure the drum

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Rear brake adjustment—F-150 and F-250

The drum brakes are self-adjusting and require a manual adjustment only after the brake shoes have been replaced, or when the length of the adjusting screw has been changed while performing some other service operation, as, for example, when taking off brake drums.

To adjust the brakes, perform the procedures that follow:

Drum Installed

Raise and support the rear of the vehicle on jackstands.
Remove the rubber plug from the adjusting slot on the backing plate.

CAUTION

Insert a brake adjusting spoon into the slot and engage the lowest possible tooth on the starwheel. Move the end of the brake spoon downward to move the starwheel upward and expand the adjusting screw. Repeat this operation until the brakes lock the wheels.
Insert a small screwdriver or piece of firm wire (coat hanger wire) into the adjusting slot and push the automatic adjusting lever out and free of the starwheel on the adjusting screw and hold it there.
Engage the topmost tooth possible on the starwheel with the brake adjusting spoon. Move the end of the adjusting spoon upward to move the adjusting screw starwheel downward and contract the adjusting screw. Back off the adjusting screw starwheel until the wheel spins freely with a minimum of drag. Keep track of the number of turns that the starwheel is backed off, or the number of strokes taken with the brake adjusting spoon.
Repeat this operation for the other side. When backing off the brakes on the other side, the starwheel adjuster must be backed off the same number of turns to prevent side-to-side brake pull.
When the brakes are adjusted make several stops while backing the vehicle, to equalize the brakes at both of the wheels.
Remove the jackstands and lower the vehicle. Road test the vehicle.

Drum Removed

CAUTION

Make sure that the shoe-to-contact pad areas are clean and properly lubricated.
Using an inside caliper check the inside diameter of the drum. Measure across the diameter of the assembled brake shoes, at their widest point.
Turn the adjusting screw so that the diameter of the shoes is 0.030 in. (0.76mm) less than the brake drum inner diameter.
Install the drum.

Wheel Cylinders

REMOVAL & INSTALLATION

Use a suitable size flare nut wrench to ...

... loosen the brake line fitting on the wheel cylinder

Remove the wheel cylinder retaining bolts and ...

... remove the wheel cylinder from the backing plate

Raise and safely support the vehicle.
Remove the rear wheel and tire assembly.
Remove the brake drum retainers, if equipped.
Grasp the brake drum and remove.
If the drum will not slide off with light force, then the brake shoes need to be backed off.

CAUTION

Remove the brake drum.
Remove the brake shoes.

CAUTION

Disconnect the brake line at the wheel cylinder.
Remove the 2 bolts securing the wheel cylinder to the backing plate and remove the wheel cylinder.

To install:

Reinstall the wheel cylinder to the brake backing plate and install the 2 retaining bolts. Torque the retaining bolts to 84-108 inch. lbs. (10-13 Nm).
Reconnect the brake line to the wheel cylinder and torque the fitting to 10-18 ft. lbs. (14-24 Nm).
Lubricate the rear brake shoe contact points on the backing plate with an appropriate grease.
Install the brake shoes.
Make sure that the brake drum and brake shoes are clean of any oils or protective coatings.
Reinstall the brake drum.
Bleed the brake system of air until a firm pedal is achieved. Top off the brake fluid in the master cylinder.

WARNING

Clean, high quality brake fluid is essential to the safe and proper operation of the brake system. You should always buy the highest quality brake fluid that is available. If the brake fluid becomes contaminated, drain and flush the system, then refill the master cylinder with new fluid. Never reuse any brake fluid. Any brake fluid that is removed from the system should be discarded. Also, do not allow any brake fluid to come in contact with a painted surface; it will damage the paint.

Reinstall the wheel and tire assembly.
Lower the vehicle.
Pump the brake pedal several times to assure a good pedal.
Road test the vehicle and check the brake system for proper operation.

OVERHAUL

CAUTION

Wheel cylinder overhaul kits may be available, but often at little or no savings over a reconditioned wheel cylinder. It often makes sense with these components to substitute a new or reconditioned part instead of attempting an overhaul.

If no replacement is available, or you would prefer to overhaul your wheel cylinders, the following procedure may be used. When rebuilding and installing wheel cylinders, avoid getting any contaminants into the system. Always use clean, new, high quality brake fluid. If dirty or improper fluid has been used, it will be necessary to drain the entire system, flush the system with proper brake fluid, replace all rubber components, then refill and bleed the system.

Remove the wheel cylinder from the vehicle and place on a clean workbench.
First remove and discard the old rubber boots, then withdraw the pistons. Piston cylinders are equipped with seals and a spring assembly, all located behind the pistons in the cylinder bore.

Remove the outer boots from the wheel cylinder

Remove the remaining inner components, seals and spring assembly. Compressed air may be useful in removing these components. If no compressed air is available, be VERY careful not to score the wheel cylinder bore when removing parts from it. Discard all components for which replacements were supplied in the rebuild kit.

Compressed air can be used to remove the pistons and seals

Remove the pistons, cup seals and spring from the cylinder

Wash the cylinder and metal parts in denatured alcohol or clean brake fluid.

Use brake fluid and a soft brush to clean the pistons ...

... and the bore of the wheel cylinder

WARNING

Never use a mineral-based solvent such as gasoline, kerosene or paint thinner for cleaning purposes. These solvents will swell rubber components and quickly deteriorate them.

Allow the parts to air dry or use compressed air. Do not use rags for cleaning, since lint will remain in the cylinder bore.
Inspect the piston and replace it if it shows scratches.