Drum Brake Service: Single-Anchor, Floating Shoe Designs

Drum Brake Service: Single-Anchor, Floating Shoe Designs

Although four-wheel disc brakes currently dominate the import brake service market, millions of drum brakes are serviced each day in independent import shops. Thanks to their age, many drum brakes present problems related not only to normal wear, but also to extended age and mileage.

and master cylinder should also be inspected. If the vehicle comes through the door with brake application complaints like rear wheel lockup or premature disc brake application on slick road surfaces, it’s possible that the combination valve is inoperative. If you’re servicing an ’80s or earlier ­vehicle, be aware that most drum brake master cylinders contain a residual check valve that increases pedal response by maintaining a small amount of hydraulic pressure in the system. To test for residual pressure, firmly apply the brake pedal and then check for a small spurt of fluid when the wheel cylinder bleeder screw is opened. ­Although it’s old technology, be aware that installing a drum brake master cylinder equipped with residual check valves on a disc brake system will cause the disc brakes to drag and wear prematurely. Remember also that residual check valves were designed out of later drum brake ­designs because they were no longer required. 

                                                               DRUM BRAKE SERVICING TIPS

 

soak the axle hub with quality penetrating oil before removing the brake drum. a light coat of synthetic caliper grease ­applied to the hub will help prevent corrosion after the drum is ­re-installed.

 

 

rapping the brake drum between the lug bolts with a two-pound or larger hammer will generally loosen the drum. in some applications, the brake drum incorporates two threaded puller screw holes designed to expedite drum removal.

 

 

 

when inspecting a drum brake, always inspect the wheel cylinder for leakage by prying away the rubber end cap. because they can’t be successfully honed, aluminum wheel cylinders should be replaced.

 

 

brake return springs not only retract the wheel cylinder pistons, they also allow the brake shoe’s self-adjusters to work correctly. drum brakes ­usually require special tools to remove and install hold-down and return springs.

 

 

The presence of a chamfer usually indicates if a brake drum can be resurfaced. At the minimum, I recommend a shallow cut to true the surface and remove the inner and outer wear ridges.

 

 

 

 

 

You May Also Like

TS Toolbox Guide February 2024

Here’s a look at some of the core feature and modern frills to consider when it’s time to move into a new office.

toolbox guide illustartion

The corporate world has offices. You hang pictures on the wall, keep a few trinkets on your desk and a few snacks in one of your desk drawers. It’s your space. As technicians, we have our toolbox. It’s our “office” on wheels. But it’s different. We have no “work from home” option. We can’t take it with us and work at a coffee shop. Our “office space” becomes far more important. This is where we make our living.The size of a toolbox and the features we choose depend on multiple factors, which have changed over the years along with automotive and tool technology. Here’s a look at some of the core features and modern frills to consider when it’s time to move into a new office.

Brake Lathe Basics

Resurfacing drums and rotors is a machining process with its own specific guidelines.

Refrigerant Oil Has to Be Right

Oil type is just as important as oil capacity.

Three bottles of refrigerant oil
Top 5 Tools: Steve Coffell, Auto World, Hazelwood, MO

Steve Coffell, a technician at Auto World in Hazelwood, MO, says his Top 5 Favorite Tools are: Related Articles – Mayhew Introduces New 14-Piece Micro Hand Tool Set – New Small Stud Extractor Now Available from Mayhew Tools – Matco Debuts 5-Piece Purple Screwdriver Set   OTC Genisys Touch – Quick scan, bidirectional control Snap-on

Wheel Bearing Adjustment Tools & Equipment

A wheel bearing that’s out of adjustment can reduce bearing life and can affect more than just the bearing. It’s important to adjust the wheel bearing endplay to the proper specifications. If the bearing set is adjusted too loose or too tight, it can cause the bearing to fail prematurely. There are a few types of assemblies, so using correct procedures and tools will ensure a comeback-free wheel bearing installation.

Other Posts

#2 Calipers & Micrometers

Calipers and Micrometers are essential measuring tools when exact precision is required.

Embracing Cutting-Edge Solutions the Industry has to Offer

Embracing cutting-edge solutions is strategic and imperative for technicians navigating the constantly changing landscape of automotive maintenance and repair.

Nadine Battah
Repairify Announces Executive Leadership Changes

The company has named Craig Edmonds as president of asTech among other executive appointments.

TPMS: Are Retrofits in Your Future?

Installing a retrofit kit can be performed with the tools and equipment you already own and use on a daily basis.

Tire tread