How To Check & Change Brake Linings

How To Check and Change Brake Shoes On A Classic Car

This guide captures ‘bygone’ advice on how to Check and Change Brake Linings on Classic Cars

To see all my ‘bygone’ advice guides please visit Classic Car Maintenance DIY Guides.

Remember folks these are ‘bygone guides’ … useful but the safety and personal protective equipment measures are reflective of bygone awareness. Stay safe.





Introduction

From a safety viewpoint, the most important part of any vehicle is the braking system. So it is important that brakes are correctly adjusted and maintained. And that when the linings wear down they are promptly replaced.

Replacing drum brake shoes is a ‘fiddly’ job often requiring patience. But it is worth persisting with because it can save you a considerable amount of money.

The adjustment of drum brakes involves keeping the brake shoes at the correct distance from the drum. On many cars this adjustment is automatic, but on those cars which have manual adjustment, it should be checked every 1,600 km (1,000 miles).

On all types of brake, whether the adjustment is automatic or manual, the drums should be removed and the linings checked for wear every 8,000-10,000 km (5,000-6,000 miles).

The linings must not be allowed to wear down to the rivets or where bonded shoes are fitted below 1.5 mm from the metal shoe.


Preparing To Free The Brake Drum

How To Check And Change Brake Linings 1
The first step is to remove the wheel. When servicing brakes. do not use the car jack. Instead. use axle stands-these are safer. The wheels remaining on the ground should also be chocked

Before the drum can be removed it may be necessary first to slack off the brake shoes, as these sometimes bind on the drum.

This is especially true of manually adjusted brakes, but quite often automatically adjusted brakes need to have their shoes slackened off too.

If you find that the shoes are gripping the drum the adjuster will have to be located and slackened off.

Girling Auto Adjust Brake Drum
This Girling auto-adjust brake drum can be removed by undoing the two retaining screws. Before actually removing the drum. mark it so you can replace it the same way round on reassembly

As the type of adjuster fitted varies enormously among makes of car and even among models in the same range, the owner’s handbook should be consulted to identify the type of adjuster fitted to your car and the procedure to be followed to slacken it off.

Failing this, the drum should be carefully inspected for signs of an adjusting nut, screw or recess in either the front or back of the drum. The table below describes the most common types of adjuster and how they can be adjusted.

Common Types Of Brake Adjuster
Common Types Of Brake Adjuster

After having slackened off the adjuster the drum should be easy to remove. Remember when working on the back brakes that the handbrake should be released first.


How To Free A Stuck Brake Drum

The drum can either be separate from the wheel hub or combined with it.

If the brake drum has two retaining screws in between the wheel bolts, or a locating flange which holds the inside edge of the drwn to the hub, then it is separate from the wheel hub.

This type of drum is removed as shown below.

Freeing Off The Brake Drum
This drum has auto-adjusting brakes. you should be able to free it with a tap from a hammer. However. 1f it sticks the adjuster may have to be slackened off

If there is no sign of either screws or flange, then the drum is integral with the wheel hub.

To remove a brake drum which is integral with the wheel hub you need first to prise out the grease cap from the centre of the hub.

You will then see a nut with castellations held in place by a split pin. After removing the pin and nut, you should then remove the spacing washer and the outer tapered roller bearing, keeping all components in their order of removal so that you know which parts to replace first when it comes to reassembly.

Some cars have a rear drum assembly which can be removed only by using a puller:

The puller is fitted to the wheel studs with the wheel nuts replaced to hold it in position. The centre bolt of the puller is then tightened down progressively until the drum and hub slide off the stub axle.

Using Brake Drum Pullers On Classic Cars
Some types of brake drum require a puller to remove them. The puller is bolted on to the wheel studs and as its central shaft is tightened down the drum is pulled off

If you do not have a puller you can still remove the drum and hub assembly by replacing parts of the drum, and using the wheel to give extra leverage. You should, however, take care to exert even pressure around the wheel to prevent the distortion of any component.

Disconnect The Handbrake Linkage

Disconnect Hand Brake Linkage
Next disconnect the handbrake linkage by removing the clevis pin. Which is held in place by a split pin. The clevis pin often becomes grooved or stepped and a worn one should be replaced.

What To Inspect on Brake Linings

The linings must not be allowed to wear down to the rivets, or, where bonded shoes arc fitted, below 1.5 mm from the metal shoe.

The drum should also be inspected for wear, distortion or heavy scoring.

If the drum is damaged it should be re­placed, as it will greatly affect the effectiveness of the brakes and drastically reduce the life of the shoes.

Check The Brake Drum For Scoring
With a finger. check the surface of the drum for scoring or any other signs of wear. Any dust in the drum should be removed with a vacuum cleaner or damp cloth so you do not inhale asbestos
Inspecting Brake Shoes On Classic Cars
If your old shoes look like this one you will probably have to change the drum too. Not only has the lining been worn right away but the brass rivets have also been worn to a shine
Classic Car Brake Shoe Change
Before fitting new shoes compare them with the old ones to be sure that you have the right replacements. In this case the old shoe (left) is not worn enough to need replacement.
Fitting Brake Shoes On A Classic Car
Whether refitting the old shoes or new replacements give the shoe a quick rub over with a file to remove any roughness or burring of the edges as this can impair the shoes movement.

When buying new brake shoes it is essential to get the correct replacement . So you should make a note of your car’s make, model and year, or, better still, the chassis number, and quote them when buying replacement parts.

Always renew brake linings on both the back wheels, both the front wheels, or on all four. For, since new shoes will grip more efficiently than old ones, replacing shoes only on one side or corner of the car would lead rothe car slewing to one side when heavily braked. To adjust, examine and replace drum brake shoes these steps need to be followed

  • First the adjuster should be slackened off so that the drum can be removed and examined.
  • Next, the shoes should be checked and re­placed if necessary.
  • Once this has been done the drum should be replaced and the brakes adjusted.

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How To Remove Brake Shoes

Before removing the brake shoes note the positions of all the components so that you will be able to reassemble them correctly.

If problems do occur, the drum on the other side of the car can always be dismantled and used for reference.

Remember though that one side is a mirror image of the other so some components will be reversed.

Removing Brake Shoes
To release the brake shoes the holding pins have to be removed This is done by compressing and turning the dish washer with pliers while holding the pin against the backplate with a finger.

The brake shoes can be retained on the backplate by three different methods. Two use springs and the third uses a clip.

Depending on the type of spring fitted, com­press the spring and twist it or compress the spring and twist the dish washer (as shown below).

The clip type can be removed by pulling the clip downwards.

Removing the clip and pin on Drum Brakes
Remove the spring and withdraw the pin from behind the back of the drum. Before going any further it is a good idea to make a note of the position of all the components to aid reassembly.
Removing Brake Shoes
Next (using a shoe horn). Lever off the shoes. Levering from the abutment end of each shoe. A screwdriver could be used for this. but it might easily slip off and damage something.

All the subsequent stages of brake shoe removal and replacement are basically the same for ail makes of drum and are covered below.

Removing return springs on Brake Drums
After you have levered both shoes out of their seatings. unhook the return springs and remove the shoes completely. If the springs are worn or stretched they should be replaced
Rubber Seals on Brake Drums
After placing a rubber band around the cylinder to prevent the piston from moving clean the backplate. To avoid damaging the rubber seals. use methylated spirits or a special cleaning fluid.

Check Brake Cylinder Movement

Check Brake Wheel Cylinder Is Free To Move
Check that the wheel cylinder is free to slide from side to side, by gripping it firmly and trying to move it. If it is at all reluctant to move then it will need to be greased
Greasing Brake Cylinders
To grease the cylinder lever it away from the backplate with a screwdriver and apply the grease with an old feeler gauge. Use only a high temperature grease such as Girling Blue Grease
Greasing An Automatic Brake Adjuster
After you have greased the cylinder and removed the rubber band holding the piston in place pull out the automatic adjuster. This should then be cleaned and lightly greased




How To Refit & Adjust Brake Shoes

How To Refit Brake Shoes
Before refitting the brake shoes grease the points on the backplate where the shoes rest. Apply the grease sparingly, as none must be allowed to get on to the brake linings.
Refitting Brake Shoes & Springs
The Job of replacing the shoes and springs 1s made much easier 1f you first secure one of the shoes. and then hook on the return springs. First fit the shoe attached to the handbrake
Refitting Brake Shoes
Next hook the lower return spring on to the other shoe and then using a shoe horn lever into place the end of the shoe that seats against the wheel cylinder.
Refitting Brake Shoes
After refitting the upper return spring. lever the upper end of the shoe into place. while keeping the springs in place. This operation is quite tricky and may take several attempts
Refitting Brake Shoes
As the linings of the shoes usually become dirty during the fitting operauon give them a quick rub over with a fine grade abrasive paper such as 400 grade wet and dry
Adjusting Brake Shoes
As adjusting the brakes by operating the handbrake is a long and laborious job. it can be speeded up a little by tapping the adjuster wheel round a couple of times before refitting the drum
Refit Handbrake Cable On Drum Brakes
After replacing the drum refit the handbrake cable. If the two parts do not line up do not strain the lever from the drum to meet the cable but lengthen the adjustable end of the cable




Notes On Drum Brake Adjustment

Automatically adjusting brakes adjust themselves in a number of different ways depending on the type fitted.

Some adjust themselves after the brake pedal has been depressed once, others require the handbrake to be operated several times.

Less common types even require being operated several times.

Less common types even require the car to be driven backwards and then stopped. In order that they are adjusted correctly the method of adjustment must be known and this information should be in the owner’s manual.

So the only attention that new ones need is to be centralized and this is done simply by pumping the brake pedal once or twice.

The procedure for adjusting manually adjustable drum brakes whether fitted to the front or rear of the car is the same regardless of the type of brake adjuster fitted.

The idea is get the brakes close to a final adjustment then to centralize them (at which point they will loosen again), and then to complete the adjustment.

What you do is:

  • First, having determined which type of adjuster is fitted to yoU1· car, screw the adjuster in until the drum is locked-that is, until you cannot turn it.
  • Second, U11do the adjuster slowly until you feel or hear it click twice; the drum should now be free to turn.
  • Third, centralize the brakes by pumping rhe brake pedal a couple of times
  • Fourth, repeat stages one and two.

If the adjuster does not click, note the amount the nut or screw needs to be turned for the drum to turn freely.

It is important to adjust all the brakes by the same amount so that the braking will be smooth and even.

Do not worry if the shoes bind on the drums a little. It is only because they are new.

It is better to leave them slightly in contact with the drum than too loose. If they are a shade tight they will soon wear down to the correct fit. But if they are loose they could be dangerous (There will be more travel in the brake pedal before the brakes ‘bite’)

With either type of brake, once the work has been completed the car should be very cautiously road tested. New shoes may give the brake pedal a spongy feel at first, as they take some time to bed in.


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