Drum Brake Systems

Across the world you’ll find millions of TRW Aftermarket Brake Drums fitted to all kinds of vehicle makes and models. The fact that they largely go unnoticed by those who rely on them is testament to the reliable, fuss-free, long life nature of our products. Countless safe journeys are completed every day, everywhere because at TRW we’re passionate about achieving total safety and industry leading quality.

With drum brake technology enjoying something of a revival and 45% of new cars still fitted with them, the demand for fail-safe, high quality replacement parts is set to stay strong for many years to come. The drum brake remains the most cost effective solution for rear braking in most cars and we’ll continue to lead the Original Equipment (OE) market – trusted by leading manufacturers and automotive industry professionals everywhere.

With over 350 references, our comprehensive and diverse drum brake range covers 46.6% of the European vehicle parc, so it’s not surprising that TRW brake drums are number two for TecDoc application coverage. Naturally, every product is manufactured to our OE specification, and as ever, everything you need to complete the job safely and swiftly is in the box.

You’ll also find that each brake drum is clearly marked with a traceability code, maximum diameter and date. And to offer the best solution for you, your customer and the environment, our drum brake range is also chrome 6-free.

The TRW range includes 61 brake drums with integrated bearings. This gives you a number of key benefits including:

• Integrated bearings to ensure perfectly accurate fitment every time, maximising safety.
• An integrated bearing design that’s simpler and quicker to fit in the workshop.

There’s also a choice of 15 bi-metallic brake drums made with steel and cast iron. With these parts, performance and safety, especially in challenging conditions, is exceptional.

• The bi-metallic construction prevents expansion when high temperatures are generated during braking.
• The spheroidal cast iron used needs less material than ordinary cast iron to withstand heavy braking loads. This material also prevents ‘twist off’ during heavy braking, transforming safety in challenging conditions.
• During the melting process, graphite is treated with magnesium to form a sphere with high tensile strength like steel.

TRW drum brakes use the trusted and durable Simplex design. For quality, quiet operation, and of course warranty cover, they lead the market. Made at our Original Equipment Pontypool plant, TRW drum brakes have some serious global customers. Ford fit them to both Focus and Fiesta models.

TRW Aftermarket wheel cylinders are far more resistant to ageing than alternative cylinders because each one is fitted with an original equipment spec rubber seal and dust caps. If you’ve seen them, and used them, you’ll know that the TRW brand on wheel cylinder castings and dust caps has always been a guarantee of premium product quality.

We supply wheel cylinders in lightweight aluminium as well as in cast iron. The automotive world demands lighter components that maximise safety, and that’s why we’ve developed wheel cylinders in lightweight aluminium bodies, because they reduce the weight added to the vehicle while retaining the same reliable performance. We can develop these innovations because we’re a global leader in the design, development and manufacture of safety critical, original equipment quality braking, steering and suspension parts and systems. Investing in the development of lightweight parts that deliver a heavyweight performance delivers better parts for you to fit, and we’ll go on developing parts like this to meet your needs.

A TRW Aftermarket Wheel Cylinder is an original equipment quality brake part, giving you like-for-like replacement that gives confidence to you and your customer. End users need to know that the invisible safety in their cars works every time. That’s why all TRW Aftermarket Wheel Cylinders are 100% end of line tested to ensure that they conform to our stringent original equipment standards. In fact, we’re so confident of the quality of our wheel cylinders that we offer an additional three-year guarantee in the event of a defect in material or workmanship.

When you choose to buy TRW Aftermarket Wheel Cylinders, you’re selecting from a range with great availability. We have 600+ part numbers in the TRW Aftermarket Wheel Cylinder catalogue and cover 52% of the European vehicle parc. With more than 600 references, that makes TRW number 1 in TecDoc wheel cylinder parc coverage.

If you’re looking for durability, trust TRW. In a benchmark study testing the durability of our wheel cylinders against two leading competitors, our wheel cylinders came out on top, with a lifespan average of over one million cycles. That’s a rating 16% higher than the nearest competitor. With TRW Aftermarket Wheel Cylinders, you can offer your customers reliable quality, excellent performance, and optimised safety every time.

Our wheel cylinders have also been rigorously tested for contamination and end of line controls. While competitor products were found to exhibit a significant level of contamination of aluminium or steel particles in the sealing area, to have seals fitted the wrong way round, or missing completely, our components came out on top. That’s yet another reason why TRW Aftermarket Wheel Cylinders are reliable, dependant, everyday components that you can fit with confidence.

We’re so confident in the quality and testing of our wheel cylinders that we offer a market-leading 3-year or 60,000-mile (100,000 km) guarantee. We have an outstanding reputation with vehicle manufacturers for our drum brake and actuation products at an OE level, so much so that, at the time of writing, actuation is our biggest area of growth in braking. And our on-going technical advances and business wins at an OE level mean that our aftermarket program benefits from unrivalled technical expertise.

We evaluate every element of the wheel cylinder to maximise safety. We do that through testing. All TRW Aftermarket Wheel Cylinders are 100% end of line tested to ensure that they conform to our stringent original equipment standards. We conduct 100% end of line pneumatic testing with complete accuracy assured by sensors within a resolution of 1,000,000. The test is conducted using the manometric method, which, by employing absolute pressure decrease, is reliable, repetitive and safe.

All rubber components in our wheel cylinders have to fulfil the following OE acceptance criteria:

• High Tensile and Tear strength
• Low compression set (20% max)
• High resistance to ageing in air at high temperature (150 - 200°C)
• High resistance to brake fluid at high temperature (4 weeks at 150°C)

If a valve fails, and the rear axle locks, drivers may lose control of their vehicle. To prevent this, TRW Aftermarket Wheel Cylinders with PCRVi fulfil the highest technical standard in order to reliably reduce the brake pressure build up at the rear brake.

Some suppliers often provide cylinders that are fitted with cheaper steel pistons that are at risk of corrosion if not surface-treated. TRW Aftermarket’s aluminium wheel cylinders are fitted with aluminium pistons. With housings and pistons that are both anodized, you can offer customers wheel cylinders with both pistons and casings that provide a corrosion resistant and wear-resistant surface.

Every TRW Superkit is a one-stop solution. It has a single part number, arrives in one box, and allows for one precise, accurate repair that is cost-effective and quick with no need to reuse worn or corroded parts. Inside your TRW Superkit box you’ll find:

• Two sets of pre-assembled and pre-adjusted brake shoes
• Two wheel cylinders
• Two automatic adjusters
• Retaining springs
• Securing pins for shoes
• Correct grease
• Comprehensive fitting instructions

With TRW you’ll get it right the first time, and every time

The safety critical importance of drum brakes means that there is no room for compromise, with maximum brake performance and stability significantly enhanced by rear axle braking - particularly in emergency situations. In the UK alone, a high volume of vehicles are fitted with drum brakes, so using and fitting the finest is a very important business.

As with other key parts such as rear shock absorbers, when vital elements wear out and lose their effectiveness they should be replaced immediately. Spring tension, for example can decrease by up to 50% in just three years. But research shows that for total safety the combined group of braking components should all be replaced, to avoid imbalance and uneven braking.

TRW Superkits are carefully designed and meticulously engineered to ensure top performance and simple fitment whilst saving you valuable time. Essentially, they work better for everyone.

• Because Superkits are pre-assembled, repair times can be up to 50% shorter, so they can save you an estimated 30 minutes per job.
• Every TRW Superkit is manufactured to our world leading OE quality standards.
• Each includes adjusters, brake shoes, wheel cylinders and all the accessories you need, such as the correct grease, caps and nuts for attachment and assembly. As a complete package it is designed to make your life easier and your work more efficient, especially when repairing French vehicles.
• Quality is beyond question, with all products made in-house and subjected to 100% end-of-line testing. You can depend on the integrity and reliability of our drum brake Superkits every time.
• Our reassuringly thorough testing programme is fully documented, approved and guaranteed by the TRW hologram that you’ll find on each Superkit box.

To further enhance our tried and trusted Superkit range, we have developed the ingenious TRW Super Incremental Adjuster. Approved and Homologated by the Federal Motor Transport Authority of Germany, the adjusters automatically maintain the critical clearance between brake shoe and brake drum.

An innovative addition to the Super Incremental Adjuster is the thermoclip, which goes between the push rod and adjuster nut. This bi-metallic component then regulates the distance between brake shoe and brake drum as the brake drum diameter expands with heating during heavy use. By increasing the length of the adjuster unit, the adjuster is prevented from operating until both brake drum and thermoclip have cooled, which prevents blocking. Standard in many OE braking systems, adjusters play an important part in maintaining optimum brake pedal pressure and feel for the driver.

TRW Superkits always include either the Super Incremental Adjuster, or one of our alternative adjuster solutions.

• They compensate for heat expansion in the brake drum.
• They are designed to stop over adjustment and shoe seizure.
• They optimise handbrake performance.
• The units are greased for a long, fault-free service life.

Every single component and detail in a TRW Superkit is made without compromise. Springs correctly locate the shoe so that there is no contact with the drum, hold the shoe firmly against the backplate and are thoroughly protected against corrosion.

Brake wheel cylinders are made from aluminium or cast iron and prevent hydraulic leaks through high quality and precise manufacturing tolerances. All rubber elements are high specification and easily match OE quality.