Caravan brakes: drum or disc? Ultimately, this topic is more about weighing up the pros and cons of both systems rather than debunking any perceived myths.
And the general consensus is that while disc brake installation is not practical for universal standardisation in the caravan industry largely due to cost, they do have some efficiency and mechanical advantages over electric drum brakes.
AL-KO’s Rob Funder says electric drum brakes in the RV industry have been around since the 1970s and have proven to be a strong and reliable braking system that offers good performance for a relatively low cost.
“Hydraulic disc brakes, whilst well known in the automotive industry, have remained relatively low in volume in the marine trailer industry and upper end of offroad RVs, and as such the manufacturing cost remains higher,” Rob said. “Increased interest in hydraulic disc brakes for the caravan market is growing, but with a good performing electric brake option, any transition will be slow.”
He adds that the biggest benefit with disc brakes is heat dissipation and the heavier the RV the more heat generally produced during heavy braking. “So the mechanical benefit would be more obvious in heavier trailers, but there is no restriction in using hydraulic disc brakes on lighter trailers, it’s more about the control systems used to operate them effectively at varying weights.”
Rob says the RV industry has and always will need to focus on keeping manufacturing costs as low as possible in this competitive global environment. “Decisions are made on appropriate engineering, safety and cost considerations, so if you have a good quality brake system which meets regulatory performance requirements and is a lower cost, it will always be preferred to a more costly system.”
He adds that electric brakes have stood up to offroad applications remarkably well, particularly when manufacturers such as AL-KO have focused on making appropriate modifications to design (such as the offroad electric brake) to provide the best possible solution for a reasonable cost. “However, disc brakes offer some basic mechanical advantages such as better heat dissipation, ease of cleaning after immersion in mud, better dispersal of water following river crossings, etc.”
Rob agrees that electric drum brakes perform exceptionally well and efficiently when the appropriate size is selected for the application. “All too often we see braking systems, whether electric or hydraulic, being used with loads in excess of the optimum. If you are making a brake selection decision, ensure the load you plan to carry is within the braking capacity of what is fitted to your RV.”
THE VITAL LINK
But, Rob says, like any braking system, electric brakes have wearing parts (such as linings) which need regular maintenance to keep the brakes in top condition so that when you need them they perform just as you want.
“We find it concerning that the average caravanner cares little for the servicing of brakes and undercarriage components on their RV when these are such a vital link in ensuring the next holiday is one to remember for the right reasons.”
For extreme rough road use, AL-KO recommends its ‘Off Road’ version of electric brakes which are specifically modified to prolong brake componentry life in extreme rugged conditions.
AL-KO also has launched two power-assisted braking models – iQ7 Outback and iQ7 Outback XTREME – for caravans with disc brakes in dusty conditions.
Both store compressed air within a pressure chamber, allowing immediate brake application the instant it is required. The iQ7 Outback and iQ7 XTREME also incorporate Breakaway technology and are designed to significantly improve stopping performance, thus providing safety and peace of mind.
David Pester, an independent caravan repairer on the Mornington Peninsula in Victoria, says he’s noticing disc brakes on the more expensive vans with bigger Tare weights.
“Disc brakes employing an electro-hydraulic actuator have several advantages over electric drum brakes with a vehicle-mounted controller,” David said. “Among the more pronounced are better cooling by shedding heat faster, and providing improved stopping power.”
But David can’t envisage widespread utilisation of disc brakes in the caravan industry unless they become more cost effective. “Disc brake hardware is expensive, and there’s more infrastructure involved.”
He adds that until the price point comes down, disc brakes will ostensibly remain the domain of larger and heavier, top-end caravans.
But he still believes the caravan industry is becoming less conservative on the cost of disc brakes. “There’s definitely a target market where manufacturers are attempting to give their customers an edge – a perfect example is the uptake on lithium batteries.”
David says disc brakes are more reliable in offroad applications. “They would be my preferred option in an extensive offroad environment.”
And although he agrees electric drum brakes are generally outperformed by disc brakes, David says they still get the job done. “Electric brakes are robust and reliable enough on 95 per cent of applications… Their performance often comes down to professional maintenance (the skill of the technician maintaining them) and the ability of the driver to adjust the brake controller (the customer knowing how to get the best out of them).”
Many motor vehicles comprise a front-disc/rear-drum brake setup, as between 60-90 per cent of a vehicle’s stopping power comes from the front wheels. However David believes such an arrangement isn’t feasible in a caravan. “You couldn’t have a ‘hybrid’ brake structure for a caravan; it’s impractical and wouldn’t work. Disc brakes and electric drum brakes are mutually exclusive concepts that have different efficiencies – plus one brake controller would not be compatible for both systems.”
The merits of disc brakes are the same for all sizes of caravans. Disc brakes can be lighter, more efficient and offer an improved towing experience even on smaller, lighter caravans.
And disc brakes are often packaged with other high-end features (i.e. luxury ensuites, independent suspension, satellite TV, washing machines) which means they are usually found where decisions are made more about quality, comfort and less on price.
But are disc brakes better suited than electric brakes to offroad applications? They certainly drain better, which can sometimes be a problem with drum brakes and they are less prone to torque variations due to temperature and speed changes.
However, electric drum brakes are efficient and offer fairly high brake torque values at a reasonable price. They generally offer trouble-free service with minimal maintenance requirements and although they have their drawbacks, they are still widely used and safely brake thousands of trailers every day in Australia.