Performing a brake shoe/drum replacement on commercial vehicles
When it comes to maintaining commercial vehicles and heavy-duty trucks, customers understandably want to minimise downtime for their fleets. Garages are under pressure to work quickly so the vehicle can get back on the road as soon as possible.
Nevertheless, replacing brake shoes and drums on a commercial vehicle (CV) or heavy goods vehicle (HGV) involves a multi-step process requiring careful inspection and adherence to manufacturer guidelines. Following proper procedures will not only reduce the risk of returns, it will also ensure safety for all road users.
In this article, TMD Friction’s Textar braking brand gives the run down on performing a brake shoe/drum replacement on commercial vehicles.
Before the technician even starts working on the vehicle, they must prepare both the vehicle and their working environment to ensure personal safety. The technician should wear appropriate safety equipment, such as gloves and eye protection. They should also ensure they have the correct tools, such as proper lifting equipment, on hand.
The vehicle should be safely parked with the parking brake engaged. It is also a good idea to consult the vehicle’s manual for specific instructions and torque specifications where required. Finally, be sure to have the vehicle’s maintenance records on hand so you can document all repairs and inspections.
Brake Drum Maintenance
Once you have everything prepared, the first step is to remove the wheel to access the drum brake. In order to remove the brake drum from the wheel hub, slacken the brake shoes using the shoe adjuster and carefully tap the drum with a rubber mallet to free it. Next, clean the components with a suitable brake cleaner such Textar Formula XT. Inspect the drum for any damage, cracks, or excessive wear and replace if any damage is found.
Brake Shoe Replacement
The next step is to remove the brake shoe retaining springs using specialised tools such as an S-Cam brake spring lever. Pay close attention to the position of the shoes and any associated parts. As with the brake drums, inspect the brake shoes for signs of wear and replace as needed, ensuring the correct orientation and fitment. Any further adjustments should be first carried out after the drum is fitted.
Cleaning The Brake Drum
Make sure to thoroughly clean off any oil or dirt before fitting the drum to ensure no debris is on the surface of the shoes. Failing to properly clean the components can have a detrimental effect on braking performance as well as shorten their service life or even damage them.
Assembly And Checks
Now you’re ready to put everything back together. Reassemble the brakes, ensuring all components are correctly installed. Check and adjust the slack adjusters, check the system for leaks, and test the brakes and adjust as needed. Finally, torque all nuts and bolts according to the manufacturer’s specifications.
Now it’s time to perform a final check. Are all brake system components now clean and free of wear? Is the air suspension functioning properly and without leaks? Are the slack adjusters and brake levers in good working order?
As a last step, make sure to inform the customer about proper aftercare procedures, including bedding in.
To Recap
- Follow manufacturer guidelines for brake shoe replacement and adjustment
- Document all repairs and inspections in the vehicle’s maintenance records
- Engage the vehicle’s parking brake, and make sure you have all the necessary protective equipment on hand, to ensure personal safety
- Fully inspect and clean all components. Replace any items that show cracks, damage, or signs of wear.
- Torque all nuts and bolts according to the manufacturer’s specifications
- Perform a final check to ensure everything is in good working order
- Inform the customer about proper aftercare instructions, including bedding in
Regular inspection and maintenance of the CV / HGV’s braking system will ensure safe and reliable operation. Make sure to follow best practices every time to minimise the risk of dissatisfied customers and returns.
