Disc Brakes Australia has just launched a new range of braking components by adding OE replacement calipers to its comprehensive, ever-growing offering of Street Series products.

The new program brings DBA even closer to its goal of being a one-stop-shop for the wheel end. DBA’s Technical Product Manager, Tony Doyle, explains “With our braking expertise of over 40 years we set out to bring to market a range of calipers that perfectly complement our long-established range of Street Series brake rotors, as well as our recently launched, market-leading range of Street Series brake pads.”

DBA’s Street Series braking products are designed to provide a no-fuss “bolt off, bolt on” experience for the mechanic. Tony says DBA’s launch strategy is demand driven, with the first applications now being available for popular 4WD models. “Before year’s end the number of SKUs will at least triple to cover further popular cars, SUVs and LCVs.” says Tony. “Ultimately, we want to offer a similarly comprehensive market coverage for our Street Series callipers as our customers have come to appreciate for our Street Series rotors and pads.”

Part of DBA’s commitment to the market as a premium brake supplier is to offer valuable technical advice. Particularly brake calipers are an integral part of the vehicle’s braking system, however their critical role in stopping a vehicle is often not well-known or understood. In fact, they are seen but very seldom serviced, replaced or discussed.

How they work

Most modern vehicles today have disc brakes on both the front and rear wheels.
In a modern vehicle’s disc-brake system the vehicle’s wheels as an assembly are basically attached to metal disc rotors that rotate along with the wheels.
The brake caliper is assembled over the rotor like a clamp. Inside each caliper is commonly fitted a pair of brake pads that create friction to either side of the disc. One to the outer side and one to the inner side.

The calipers are a cast and machined product with varying areas of high tolerance as an assembly. When you step on the brake, brake fluid from the master cylinder creates hydraulic pressure with resultant force then pushing on the pistons in the brake caliper. These pistons move forward away from the caliper body driving the brake pads against the disc face. The action of forcing the pads against the disc surface slows the vehicle or brings it to a stop.

Calipers come in a range of finishes from as cast and or painted depending on the vehicle make. In some higher spec vehicles these can also be customized to suit. Depending on the vehicle type and make they differ greatly in size and form. Some have a mass size double those on some other vehicles and may be dependent on the GVM of the vehicle, but they all essentially work the same in one of two ways.

There are two main types of calipers in operation on today’s modern vehicles: floating calipers and fixed calipers.

Floating calipers move in and out relative to the disc and may contain only one or two pistons on the inboard side of the disc. This piston within the caliper assembly pushes the entire caliper when the brakes are applied. This action, as described earlier slows the vehicle by creating friction from the brake pads on both sides of the disc.

The second type, fixed calipers, as the name implies, don’t move, these have pistons arranged on opposing sides of the rotor. Fixed calipers are generally preferred for their braking performance and are generally more expensive than the floating kind. This is in part by being larger in construction and having more parts per the assembly. Some high-performance fixed calipers may have up to 2, 3 or 4 pairs of pistons arranged on each side of the rotor.

How to tell if they need replacing

In the main calipers are designed to be a robust part of the brake system. However, over time, the heat generated in driving can cause a breakdown in the seals within the pistons and caliper piston bores. There are a number of tell-tale signs that you may have issues with your calipers –

Does the vehicle pull to one side when applying the brakes? If a brake caliper or slide is seized this may cause the vehicle to pull to one side under the application of the brake. You may also experience the vehicle pulling under normal driving conditions.
When inspecting the vehicle do you notice any fluid leaks? The calipers are activated by hydraulic fluid and under increased pressure when the brake is applied. Over time due to the constant pressure and or wear, the caliper can develop brake fluid leaks from the piston seal or bleed screw.
Under braking does the pedal feel spongy or soft? The application of force on a fluid in a sealed system would not have a ‘soft’ feel. By attempting to compress a fluid the feel should get stronger. A leaking caliper can cause a spongy or soft feel as the fluid is escaping and hence not providing the expressed rigid feel.
In combination it should be noted that a seized piston or sticking slide can create excessive clearance between the pad and rotor and may cause a variation in pedal feel or feedback.
The result of any or all of the outlined potential issues is – if you do have a faulty caliper, will result in reduced braking ability.

Other attributes that can be impacted by caliper malfunction are uneven brake pad wear.
Uneven brake pad wear may be a result of sticking caliper slide pins thus creating bias in wear characteristics. Further signs of ineffective caliper operation may be the experience of abnormal noise. The resultant seizing of brake caliper will wear down the brake pads unevenly with the end result being noise, requiring early brake pad/caliper replacement.

At any service interval it is imperative the entire brake ‘system’ is checked and reviewed. The effective braking of a vehicle relies on all parts of that system working in unison the be effective.

While attempting to repair a leaking or otherwise faulty caliper is not uncommon, studies show that the time required to do so, in combination with running the risk of the fault reoccurring within a short period of time, makes a replacement of the caliper the by far more economical solution. DBA’s range of Street Series calipers puts workshop owners and mechanics in a position where they can do just that – bolt off, bolt on, and save time and money.

DBA’s Street Series brake calipers are available as single units for direct OE replacement and require no modification to the vehicle. They are being supplied including brackets, however without brake pads to allow for universal caliper – pad combinations.

To learn more about DBA’s new Street Series caliper range email sales@dba.com.au or call 1800 730 039.