Are you using the right brake shoes?

Brake Shoe Linings Demystified

In the case of brake shoe linings, one shoe does not fit all. There are several factors that must be considered when choosing the right brake lining for your truck or trailer. It’s all about application and TRP have the answers to your brake shoe needs.

Not all aftermarket linings are created equal. So how do you select the right brake shoe lining for your vehicle? Well if you know your truck’s application, TRP can recommend a shoe for you.

As a requirement, all brake linings are designed to exceed maximum load limits in Australia, so axle ratings, while important, should not play a huge role in determining the right lining. What is right for one application may not be suited to another. Brake linings certified at 23,000 lb can prove to be much too aggressive for some applications, causing the brake drums to wear prematurely or result in brakes that ‘grab’. Similarly, brakes certified at 21,000 lb may not provide sufficient braking power to stop some heavy vehicles.

All TRP brake linings exceed the maximum gross axle weight rating (GAWR) limit in Australia. TRP brake shoe linings are available in either 21,000 lb (21K) or 23,000 lb (23K) GAWR. Both these linings are designed to pull the same torque. The difference in the linings, however, is in the strength, wear, noise and consistency level.

Choosing a 23K-rated lining doesn’t mean it is right for your application. Nor does it mean that you’ll get any service life improvements from that lining. What is important is the application that the lining will be used in.

There are various factors that should be considered when picking the right lining.

• Is your vehicle used in on-highway or off-highway conditions?
• What type of load does it haul?
• What is the braking frequency?
• How often is the vehicle serviced?
• What are the driving habits of the vehicle’s operator?

These are all important questions to consider before you select a lining.

Typical Brake Shoe Applications

The above table is a guide only. Best practice when choosing the right lining is to follow the manufacturer’s recommendation.

What is GAWR?

A vehicle’s GAWR is the specific weight determined to be the maximum allowable weight that can be placed on a vehicle’s axle. The GAWR includes the weight of the truck and/or trailer, passengers and cargo. Drive, steer and trailer axles all have individual GAWR’s. Think of GAWR as a weight limit for each of the axles for your truck and trailer.

Overloaded or unevenly distributed heavy loads can make it difficult to control the truck and put stress on the brake system, causing the brakes to be less effective.

Brake Lining Selection Guide

Road Type
On-highway truck and trailer
On/Off-Highway, steep grades, worksites, city roads
Load Types
General cargo, produce
Liquids, gases, mining, logging, refuse, construction
Braking Frequency
Low, mostly interstate, moderate, a mix of interstate and urban
Moderate to high, any environment
Maintenance Habits
Regular maintenance and services, maintenance as needed
Poor, intermediate service, brakes serviced when problem appears
Driver Habits
Gentle to average
Average to aggressive

Rigorous testing

FMVSS 121 standard

TRP brake shoes are independently tested to Federal Motor Vehicle Safety Standard (FMVSS) 121, an industry-recognised standard that tests whether a friction material has sufficient frictional characteristics to be safe on a given application. FMVSS 121 is not a comparison of linings but a measure of each product as it relates to the standard, so a product either is a pass or fail on the FMVSS 121 test, as the standard cannot be exceeded.

So how does this US standard apply to Australia and New Zealand? The fact is that both Australian and NZ vehicle standards are for the fully dressed axle, so it is important to use a recognised standard like FMVSS 121 to test the performance of the friction material.

TRP brake shoes are tested to the FMVSS 121 standard, which ensures that the linings are put through standardised testing. This, in turn, verifies that the lining passes set criteria at a given weight load. An independent testing facility based in the US, Link Manufacturing, performed the FMVSS 121 test on the TRP 21K and TRP 23K lining materials. Among other tests, the test comparing lining weight loss in grams showed that TRP linings outlast the OEM equivalent by up to 30 per cent and deliver a better return on investment.

TRP also commissioned independent FMVSS 121 testing on popular OEM and aftermarket brake shoes in the market. By graphing the results, TRP was able to compare the performance of each of the different linings. The testing showed TRP linings performed excellently when compared against aftermarket and OEM brake lining results.

Brake drums also play an important role in dissipating heat that is generated through braking. Overheating of the linings can cause glazing, blisters and discolouration, which can lead to premature wear and reduced performance. TRP drums have excellent heat dissipation properties – a fact that has been tested and proven by the FMVSS 121 test.

ECE R90 standard

TRP brake shoes are also tested and certified to ECE R90, where applicable.
ECE R90 is a European standard, recognised by the Australian Design Rules (ADR). A brake shoe tested to ECE R90 has to perform within 15 per cent of the OEM product and tests have proved that all TRP shoes certified to ECE R90 exceed this requirement. There are a number of tests that are performed during ECE R90 testing. One of the most important is how the aftermarket lining performs against the OE product. The lining needs to perform within 15 percent of that of the OEM product. When the TRP brake products were tested in direct comparison with the OE equivalent, they were found to perform close to and in some instances better than the OE product.

However, since ECE R90 testing is a European standard, it can only be performed on European application brake shoes.

TRP benefits

TRP Parts is a one-stop shop for brake shoe kits, offering a comprehensive range that suits most truck and trailer applications, including American and European drivelines. An aftermarket brand of the PACCAR group, TRP offers reliable and affordable parts that are backed by the same standard of quality that you would expect from PACCAR. Manufactured using OE specifications, TRP brake shoes are available in 21K GAWR and 23K GAWR.

There are many benefits to selecting TRP brake shoes:

• The TRP range is designed, tested and engineered to meet the demanding conditions on Australian roads, ensuring TRP brake shoes are reliable and built for purpose.
• The automated riveting process eliminates any potential human error.
• The TRP range is certified to FMVSS-121 and ECE R90 (where applicable) to ensure the brake shoes meet recognised, industry-wide standards.
• The 300 hours salt spray paint finish ensures a high resistance to corrosion and rust.
• OEM quality hardware kit helps extend the life of the shoe.
• TRP offers a 12-month hassle-free warranty.

So next time you need new brake shoes for a vehicle, consider the application that you are using your vehicle in before deciding which shoe lining is the perfect match.

For further information on TRP brake shoe range, visit the TRP Brake Shoe Product Guide.