Car Mechanics (UK)

Back To Basics: Brake drums

Rob Hawkins looks at routine servicing of brake drums and combined discs and drums.

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Brake drums have largely been superseded by discs, but they are still used on a wide range of vehicles on the rear and some models may have disc brakes all round, but incorporat­e a drum set-up at the rear for the handbrake. The trouble with brake drums is that they often get neglected because they are potentiall­y more awkward to service and inspect than a brake disc set-up. It’s only when a problem arises, such as an inefficien­t or dragging handbrake, that it’s time to remove the drums and take a look. However, routine servicing can ensure they last for several years and only need an annual clean and lubricatio­n to keep them in good working order.

So, the following pages outline what’s generally involved in servicing drum brakes. There are numerous difference­s, including the means of adjusting the brake shoes (automatic or manual), how the drum is secured and the seemingly complicate­d layout of the brake shoes with a bewilderin­g assortment of springs.

Ford’s long-lasting pick-up has a reputation for being a durable and robust workhorse. We had the chance to help service a 2006-plate Ranger 4x4, which has a 2.5-litre diesel engine. Most of the Rangers from this era, and those that are of the age where DIY servicing appeals, have the 2.5-litre diesel engine with a manual gearbox and four-wheel drive.

Difference­s may be minor, but they’re important when it comes to servicing. For instance, the rear drum brakes are self-adjusting on some models, whereas other owners have an access hole on the

backplate at the bottom that allows the brake shoe adjuster to be turned.

The correct specificat­ion of oil required for the engine, gearbox and rear axle varies, so it’s worthwhile checking with a local motor factor, or online where motor factors such as Euro Car Parts

(eurocarpar­ts.com) and oil specialist­s such as Millers Oils (millersoil­s.co.uk)

list the recommende­d lubricants. We also discovered the service schedules vary between different sources, so we consulted Ford USA and Autodata to compile a suitable list.

The following steps provide a general overview of what’s involved in servicing a Ford Ranger and were all completed with Tasker and Lacy of Leeds.

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?? ??  If a locating screw is fitted 4 to the face of the brake drum, remove it. This should not be a tight fit, but it may have corroded and seized, so you may need to use an impact driver, or if the head is damaged, you may need to drill it out.
 If a locating screw is fitted 4 to the face of the brake drum, remove it. This should not be a tight fit, but it may have corroded and seized, so you may need to use an impact driver, or if the head is damaged, you may need to drill it out.
?? ??  Some brake drums require 3 the hub nut to be undone to be able to remove them, such as this rear drum on a Vauxhall Tigra. A hubcap may be fitted, which will need to be prised off. Extract any split pins, then undo the hub nut and fully remove it.
 Some brake drums require 3 the hub nut to be undone to be able to remove them, such as this rear drum on a Vauxhall Tigra. A hubcap may be fitted, which will need to be prised off. Extract any split pins, then undo the hub nut and fully remove it.
?? ??  Fitting new brake shoes can 9 be quite a fiddly procedure. Note how the old ones are fitted and make sure the new parts are fitted in the same positions. It may help to remove the old parts, lay them on the floor and assemble the new ones first.
 Fitting new brake shoes can 9 be quite a fiddly procedure. Note how the old ones are fitted and make sure the new parts are fitted in the same positions. It may help to remove the old parts, lay them on the floor and assemble the new ones first.
?? ?? 8  Check the thickness of the braking material on the brake shoes. It usually needs to be at least 2mm thick and evenly worn. If one or both shoes need replacing, all shoes on the axle (ie both rears) should be renewed. The shoes are usually secured with springs.
8  Check the thickness of the braking material on the brake shoes. It usually needs to be at least 2mm thick and evenly worn. If one or both shoes need replacing, all shoes on the axle (ie both rears) should be renewed. The shoes are usually secured with springs.
?? ?? If a new brake drum is being fitted, 11 and the hub nut had to be undone to remove the old one, then you may need to fit a new wheel bearing inside the centre hole of the new drum. The bearing races may need to be drifted into position and the bearings fitted with grease.
If a new brake drum is being fitted, 11 and the hub nut had to be undone to remove the old one, then you may need to fit a new wheel bearing inside the centre hole of the new drum. The bearing races may need to be drifted into position and the bearings fitted with grease.
?? ?? 6 If to the remove, brake revisit drum our is proving previous difficult steps to double-check everything has been undone or slackened. Brake drums with automatic adjustment can be difficult to remove, so you may need to use a couple of pry bars to evenly prise them off.
6 If to the remove, brake revisit drum our is proving previous difficult steps to double-check everything has been undone or slackened. Brake drums with automatic adjustment can be difficult to remove, so you may need to use a couple of pry bars to evenly prise them off.
?? ?? When you’re ready to attempt to 5 remove a brake drum, hit the face of it with a hammer to help release the brake shoes. Do not hit the edges of the drum as you risk warping it. Prise the drum off by hand, easing it off all the way around.
When you’re ready to attempt to 5 remove a brake drum, hit the face of it with a hammer to help release the brake shoes. Do not hit the edges of the drum as you risk warping it. Prise the drum off by hand, easing it off all the way around.
?? ?? The inside of the brake drum should 10 be inspected for excessive wear and renewed if necessary. A lip can form around the outer inside edge of the drum, which would have made it difficult to remove. If the rest of the material inside the drum is okay, the lip can be ground off.
The inside of the brake drum should 10 be inspected for excessive wear and renewed if necessary. A lip can form around the outer inside edge of the drum, which would have made it difficult to remove. If the rest of the material inside the drum is okay, the lip can be ground off.
?? ?? Peel back the rubber boots of the 12 wheel cylinders to see if brake fluid has leaked out. The seals inside the wheel cylinder can wear, but can be replaced – although complete wheel cylinders are often more economical to fit.
Peel back the rubber boots of the 12 wheel cylinders to see if brake fluid has leaked out. The seals inside the wheel cylinder can wear, but can be replaced – although complete wheel cylinders are often more economical to fit.
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?? ?? With the brake drum 7 removed, spray over the brake shoes and surroundin­g parts with brake cleaner. Use a wire brush to clean the backplate and around the brake shoes, spraying more brake cleaner to remove the brake dust.
With the brake drum 7 removed, spray over the brake shoes and surroundin­g parts with brake cleaner. Use a wire brush to clean the backplate and around the brake shoes, spraying more brake cleaner to remove the brake dust.
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?? ??  If you are not fitting new brake 13 shoes, use a screwdrive­r to clean the leading edges of the braking material. This is where brake dust can build up and reduce braking effort. Lift each brake shoe away from the backplate and scrape off any corrosion.
 If you are not fitting new brake 13 shoes, use a screwdrive­r to clean the leading edges of the braking material. This is where brake dust can build up and reduce braking effort. Lift each brake shoe away from the backplate and scrape off any corrosion.
?? ??  If there’s a mechanical adjuster 14 for the brake shoes, check this is free-moving and spray over it with a light grease. The adjuster can be removed, stripped and lubricated if necessary. Note which way it needs to be turned to adjust the brake shoes in and out.
 If there’s a mechanical adjuster 14 for the brake shoes, check this is free-moving and spray over it with a light grease. The adjuster can be removed, stripped and lubricated if necessary. Note which way it needs to be turned to adjust the brake shoes in and out.
?? ??  When you’re ready to refit the 15 brake drum, make sure the brake shoes are centralise­d using a couple of screwdrive­rs, as shown here. Manoeuvre the drum on, then adjust the shoes (if they can be adjusted) until the drum locks, then back-off the adjuster by a quarter of a turn. Take up the slack in the handbrake cable.
 When you’re ready to refit the 15 brake drum, make sure the brake shoes are centralise­d using a couple of screwdrive­rs, as shown here. Manoeuvre the drum on, then adjust the shoes (if they can be adjusted) until the drum locks, then back-off the adjuster by a quarter of a turn. Take up the slack in the handbrake cable.
?? ??  If a hub nut had to be undone to 16 be able to remove the brake drum, this will need to be refitted and correctly torque-tightened before fitting a new split pin (if fitted before). Refit any securing screws. Pump the brake pedal then, after a test-drive, check the brake drum isn’t dragging and getting too hot.
 If a hub nut had to be undone to 16 be able to remove the brake drum, this will need to be refitted and correctly torque-tightened before fitting a new split pin (if fitted before). Refit any securing screws. Pump the brake pedal then, after a test-drive, check the brake drum isn’t dragging and getting too hot.
?? ?? Equipment required › Jack › axle stands (or ramp) › oil trays › sockets/spanners 9-24mm › Torx T55 › 7mm Allen key › oil filter wrench › screwdrive­rs › wheel brace › pry bars › battery tester › antifreeze hydrometer › hammers › rubber mallet › wire brush › tyre pump › torch › torque wrench › caliper windback tool or G-clamp › water pump pliers › rags for cleaning › disposable gloves › clean jug and funnel › penetratin­g fluid › petroleum jelly › spray grease › multi-purpose grease › brake cleaner › copper grease › brake grease › grease gun
Equipment required › Jack › axle stands (or ramp) › oil trays › sockets/spanners 9-24mm › Torx T55 › 7mm Allen key › oil filter wrench › screwdrive­rs › wheel brace › pry bars › battery tester › antifreeze hydrometer › hammers › rubber mallet › wire brush › tyre pump › torch › torque wrench › caliper windback tool or G-clamp › water pump pliers › rags for cleaning › disposable gloves › clean jug and funnel › penetratin­g fluid › petroleum jelly › spray grease › multi-purpose grease › brake cleaner › copper grease › brake grease › grease gun

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