The Importance of HGV Air Tanks in Lorries
For HGV trucks that carry heavy goods and travel for miles along sometimes hazardous stretches of road, it's important to check that your air tank is working efficiently and meeting the required safety standards. In this guide, we look at the benefits of a well-functioning air tank, also known as an air reservoir, and how it works alongside air compressors to keep emissions to a minimum. We also cover the dangers of neglecting to drain your reservoirs, particularly as colder months approach.
What Is an HGV Air Tank and Why Does It Matter?
An air tank, or air reservoir, is a core component of an HGV's braking system. Rather than relying solely on hydraulic pressure, air brake systems use compressed air to apply braking force, and the air tank is where this compressed air is stored and managed. Given the size and weight of most HGVs, having a reliable, properly maintained air tank is essential for safe, consistent braking performance on every journey.
The Functions of Air Tanks
A heavily loaded vehicle requires a strong braking system to ensure it stops safely. Air brake systems allow the brakes on large trucks to be applied more effectively than hydraulic braking systems, since hydraulic brakes typically don't supply as much force as air brakes. This highlights just how important air tanks are, and why it's essential to ensure yours is working properly for a safe journey.
The most common use of air tanks is within the brake system itself. Air tanks use compressed air to operate the service brakes, as well as to release the parking brake. In an emergency, the parking brake can also be used to bring the vehicle to a stop, thanks to the different air distribution systems inside the chamber. This makes your vehicle far more reliable in the event of an emergency, and is one of the hidden features that improves everyday braking performance without drivers necessarily realising it.
The air reservoir doesn't just store compressed air; it also acts as an outlet for two separate brake systems. Compressed air passes through the air dryer before being stored in the reservoir, which then supplies this air to both the primary and secondary reservoirs. The primary reservoir stores air for the main foot, or "service," brake system, whilst the secondary reservoir stores additional compressed air to operate the steering axle brakes. This dual-system design provides an important safety backup, helping to ensure the vehicle can still brake effectively even if one part of the system develops a fault.
Did you know? You can also use your air tank to inflate your tyres. Simply make sure the vehicle's engine is running, then release the air through the air tank valve.
Avoid Winter Woes: Drain Your Air Tanks Regularly
With colder months looming, it's more important than ever to regularly drain the air reservoir. Over time, a build-up of oil, water, and other contaminants from the air compressor can accumulate inside the tank, and in cold weather, this moisture can freeze. The resulting icy mixture can cause parts inside the chamber, including valves and supply lines, to malfunction, potentially causing significant damage to your vehicle's braking system.
To prevent this, you should regularly drain the sludge and moisture using the water drain valve. If you notice signs of rust on your air tank, or discover broken valves, straps, or tensioning bands, it may be time to replace the affected air tank parts entirely rather than risk a failure further down the line.
Signs Your Air Tank May Need Attention
- Visible rust or corrosion on the tank's exterior
- Broken, stiff, or leaking valves
- Damaged mounting straps or tensioning bands
- A hissing sound indicating an air leak
- Slower than usual brake response
Catching these issues early through regular inspection can help prevent more serious, costly problems developing within the wider air brake system.
The Future of Air Tanks
As more companies across the transport industry strive towards zero emissions, it's increasingly important to ensure your fleet's carbon footprint is kept to a minimum. Many new air compressors are now oil-free, meaning there's no more oil contamination within the air tanks, resulting in longer-lasting, more reliable air systems overall.
Despite major manufacturers such as Volvo announcing plans to distribute more electric HGVs globally, air tanks are expected to remain an important safety feature for the foreseeable future. The air brake system may even play a role in the development of electronic-reliant technology, as engineers look to replicate the reliability and strong force that compressed air systems offer. It's possible that compressed air and electric power could eventually combine to replace traditional hydraulic brake systems altogether. For now, though, it's clear that air tank systems are here to stay, thanks to their proven reliability across all types of HGVs.
Conclusion
Air tanks may not be the most talked-about component of an HGV, but they play a vital role in keeping vehicles safe on the road. From powering the service and parking brakes to supporting emergency stopping performance, a well-maintained air tank is essential for reliable, efficient braking. Regular draining, particularly during the colder months, alongside routine inspections for rust, leaks, and damaged components, will help extend the life of your air tank and keep your vehicle roadworthy.
TruckSpares365 offers a wide range of air tanks and air brake system parts to suit numerous HGV brands, helping you keep your fleet safe, compliant, and ready for the road ahead.
