A Guide on Brake Shoe Linings

What Shoe is Right For You?

One Shoe Does Not Fit All

TRP® Brake Shoe linings are available in either 21,000 lb or 23,000 lb Gross Axle Weight Rating (GAWR). So why are there 2 different types of linings available and which one is best suited for your application?

This guide was developed to help you understand why there are different types of lining material and to help you identify which lining is best suited for your application.

There are several different factors that need to be taken into consideration when choosing the right brake lining for your truck or trailer. All brake linings are designed to exceed maximum load limits in Australia so axle ratings, whilst important, don’t play a large role in determining the right lining.

Consideration however, must be given to load, road type, braking frequency, maintenance practices, and driver habits when determining the right lining type.

What is right for one application may not be suited to another. Brake linings certified at 23,000 lb. could be much too aggressive for some applications, causing the brake drums to wear prematurely or result in brakes that “grab”. Likewise, brakes certified at 21,000 lb. may not provide sufficient braking power to stop some heavy vehicles.

21,000 GAWR Friction Material

The TRP® 21K GAWR grade friction is stable and provides excellent wear and fade characteristics. It has consistent braking characteristics, low noise and provides great stopping power. It is best suited for on-highway trailer and truck applications.

23,000 GAWR Friction Material

The TRP® 23K GAWR grade friction material performs extremely well in demanding applications. It is formulated to handle high braking duty cycles encountered in city pick-up and delivery and highway applications where steep grades are negotiated. It is recommended in refuse, mixer, off-road, bus and tanker applications. It provides excellent lining life, superb stopping power, and superior resistance to fade.


Gross Axle Weight Rating

A vehicle’s Gross Axle Weight Rating (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. You can 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.

It’s important to note that all TRP® brake linings exceed the maximum GAWR limit in Australia. However, choosing a 23,000 lb rated lining doesn’t mean it is right for your application. Nor does it mean that you’ll get any service life improvements from the lining. What is important is the application that the lining will be utilized in.


Brake Lining Selection Guide

The below table has been developed to help you decide which is the right shoe for you and your application.

It’s important to note that linings rated 23K GAWR are not necessarily better. It’s all about the application that you are using your vehicle in.


FACTORS 21,000 GAWR LININGS 23,000 GAWR LININGS
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


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.


TRP® Brake Shoe Identification

FEATURES & BENEFITS


  • Most truck and trailer applications are covered in the TRP® range, offering a wide selection and a one-stop shop
  • Designed, tested and engineered to meet the demanding conditions on Australian roads, ensuring TRP® brake shoes are reliable and built for purpose
  • Automated riveting process eliminates any potential human error
  • Certified to FMVSS-121 and ECE R90 (where applicable) to ensure TRP® Brake Shoes meet recognised, industry-wide standards
  • 300 hours salt spray paint finish ensures a high resistance to corrosion and rust
  • 7 long weld points for strength and matched to OE specs increases durability and extends the service life
  • OEM Quality hardware kit helps extend the life of the shoe
  • 12 Month hassle-free warranty for peace of mind

TRP® Brake Shoes and the friction material can easily be identified by the side markings and part numbers.


The 21,000 lb linings have a green edge colouring and part numbers all start with TRP21





The 23,000 lb linings have a gold edge colouring and part numbers all start with TRP23





EDGE MARKINGS EXPLAINED

Every brake shoe has an edge marking which can tell you a lot about that particular shoe and friction material. Below is an explanation of what those markings mean.


TEST RESULTS

Not All Aftermarket Linings Are Created Equal…

TRP® Brake Shoes are independently tested to FMVSS 121, an industry recognised standard that tests whether a friction material has sufficient frictional characteristics to be safe on a given application.

TRP® Brake Shoes are also tested and certified to ECE R90 where applicable. This is a European standard, recognised by Australian Design Rules (ADR). A brake shoe tested to ECE R90 has to perform within 15% of the OEM product and all TRP® shoes certified to ECE R90 exceed this requirement.


WHAT IS FMVSS 121 STANDARD?

FMVSS 121 stands for Federal Motor Vehicle Safety Standard 121 and tests whether a given friction material has sufficient frictional characteristics to be safe on a given application.

FMVSS 121 is not a comparison of premium and standard linings. It is a measure of each product as it relates to the standard.


WHY TEST TO FMVSS 121 STANDARD?

Testing TRP® shoes to the FMVSS 121 standard ensures that the linings are put through standardised testing. It verifies that the lining passes a set criteria at a given weight load.

Australian and New Zealand vehicle standards are for the fully dressed axle, so it is important that we use a recognised standard like FMVSS 121 to test the performance of the friction material.


MATERIAL TESTED AND TEST PARAMETERS

The test was performed by Link Manufacturing, an independent testing facility based in the US. The FMVSS 121 test was performed on the following Linings:

21,000 lb GAWR

TRP21K Lining Material

23,000 lb GAWR

TRP23K Lining Material


TESTING PARAMETERS

  • Air Brake Chamber 30/30
  • Slack adjuster 5.5
  • Factor 165 (30 x 5.5 )

*It’s important to note that we tested to factor 165 for both standard and premium linings. The factor is calculated by multiplying the slack adjuster arm length by the air chamber diaphragm size. (30 x 5.5 = 165). We test to this factor as most class 8 trucks use a 5.5” slack adjuster and a 30/30 air chamber.

Please see the PDF version of the Brake Shoe Guide below for the detailed Test Results.