Should I Convert Drum Brakes To Disc Brakes?

Disc brake conversions are becoming more and more popular these days, and for a good reason: A disc brake conversion is a great upgrade. If you’re wondering if you should convert your drum brakes over to disc brakes, the answer is a resounding yes. A drum to disc conversion is one of the best “bang for the buck” upgrades you can make to your vehicle. If you convert, your vehicle will stop better, stop more consistently, and your new disc brakes will be easier to maintain.

Here’s more info about the benefits of drum to disc brake conversion.

The Most Common Problems With Drum Brakes

Drum removal
Image Credit: BustedKnuckleVideo

Drum brakes have been around for a long time, and for most of their life the problems have always been the same:

  • Wet weather performance issues: If the weather is wet, drum brakes get wet. But drum brakes don’t drain the water off as well as disc brakes, so they don’t perform quite as well in wet conditions.
  • Rust: The internal components of the drum brake mechanism can rust, because the water that gets inside the drum doesn’t always evaporate away quickly. Rust can cause the brakes to malfunction – for example, automatic brake adjusters can rust in place, rendering drum brakes nearly worthless once the shoes get a little wear.
  • Difficult to work on: Drum brakes can be hard to work on, especially if you’ve got a larger vehicle. Often times the drums are difficult to remove due to rust/corrosion problems.
  • Difficult to inspect: The brake shoes and drum friction surface are hidden from view. The only way to inspect them is to pull the wheel and the drum.
  • Lots of possible ways they can fail: A brake drum can become scored or develop martensite spots; Drums can also crack or get out of round. This leads to issues with performance, noise, and premature brake shoe wear. While some of these issues can be fixed by reboring the drum, drum replacement is often the only solution for an older vehicle.
  • Fade: Drum brakes don’t cool off as well as disc brakes (air doesn’t have easy access to the pads). So, drum brakes will fade quickly.

By any measure, disc brakes are a major upgrade over drum brakes. Disc breaks tend to work great in wet weather, a fairly resistant to corrosion, are very easy to inspect (and considered easy to work on), and tend to function well even as rotors begin to wear or become uneven. Disc brakes also resist fade.

The Benefits of Having Disc Brakes on Your Vehicle

If you upgrade your old drum brakes to disc, you’ll notice quite a few improvements in your vehicle.

1. Better Performance In Wet Weather

All things being equal, disc brakes will stop your vehicle faster than drum brakes in wet weather. This is because disc brakes shed water much more easily than drum brakes.

2. Easier Maintenance

Disc brakes are self adjusting, so the only typical maintenance item is a brake pad replacement. Inspecting your brake pads is easy too – on almost all disc brake systems you can assess brake pad life and rotor condition visually.

3. More Consistent Braking Over the Life of the Pads

Disc brakes use flat pads rubbing against flat rotors. Even when the pads are due to be replaced, they will still be flat. This means that braking performance will still be almost the same as when they were new.

Drum brakes, on the other hand, used curved shoes that rub on the drum’s curved friction surface. As the shoes wear, they wear unevenly. There can also be out of round issues with the drum. This means drum brakes can degrade over time in a way that disc brakes do not.

4. Less Unsprung Weight

Disc brakes are much lighter than drum brakes – a typical rear brake drum on an older 3/4 or 1 ton truck or van will weigh nearly 50 lbs. With two drums on the axle, that’s 100lbs that move up and down every time the truck hits a bump.

Disc brakes typically weigh about half as much as drum brakes, which means the axle weight is quite a bit lower. The less the axle weighs, the less “unsprung” weight the suspension has to carry. When unsprung weight is reduced, vehicles tend to ride better and shocks tend to last longer.

5. Less Rotational Inertia

Another benefit of disc brakes being lighter than drum brakes is that they create less rotational inertia. In addition to stopping the weight of your vehicle, brakes also have to stop the inertia created by their own rotation. A lighter brake takes less effort to stop. They also take less effort to get going, which helps gas mileage a bit.

How to Convert to Disc Brakes

Lug conversion kit

Converting your brakes doesn’t have to be difficult. All you need is a disc brake conversion kit. Installing one of these kits is a straightforward process that involves removing the old drums, attaching a set of brackets to your wheel hub or axle flange, and then installing the rotors and calipers and hooking everything up. Here’s a good set of instructions on converting to disc brakes.

If you have an older truck or van with an eight lug axle (or, with a 14 bolt axle that has six or eight lugs), we’ve probably got the disc brake conversion kit you’re looking for.