IT’S no secret that Aussie cars didn’t have great brakes back in the 60s and 70s. But as we keep jamming horsepower into cars of this era – which we drive on crowded roads full of dingbat drivers – the need for heavy-duty braking artillery has never been more important.
Victoria’s Hoppers Stoppers has been providing street machiners with the whoa needed to match their go for decades, and the company has just launched schmick new four- and six-piston caliper offerings for LC-UC Toranas.
Designed around a fat 330x32mm ventilated rotor and with a modern slide-on hub carrier, the new Hoppers kits require a 17-inch (or larger) wheel for clearance. The kits are ADR-compliant and still use Aussie-designed components that are of original manufacturer specs. This benefits the end user who needs to get their project approved for road use.
“We can give customers all the info they need to take to an engineer and tick the job off, because we use production components where feasible and suitable,” says Hoppers’ Duncan Benn. “The testing has already been done by the OE manufacturer, and the data is there for engineers to see and reference.”
The calipers are a similar design to an AP Racing unit, but they are Australian designed and made. “And we have pad-mounted it with a new bracket design to also suit better, bigger rotors,” explains Duncan. “The more pistons you have in a caliper, the more even clamping force you have on the pad itself. If you tried to match our six-pot’s clamp force with a single-piston caliper, you’d have one big pressure point in the middle with the outsides of the caliper flexing out.
“Similarly, opposed-piston layout calipers make them more rigid, which gives more consistent pedal feel compared to a sliding-piston caliper, which can flex. This isn’t normally a factor in most regular street driving, but at nine-tenths it is crucial.”
While this top-spec six-piston kit will run you up to $4500, Hoppers has Torana brake kits starting from $1500 (290mm discs, two-pot calipers). The big kits are available now in limited colours, with more colours available by order.
We followed along as the Hoppers Stoppers team fitted their new kit to a tidy LX Torana sedan packing an injected 5.0-litre.
1. One look at the Torana’s original PBR single-piston calipers and tiny, solid brake rotors should give you the hint as to why you’d want to upgrade your brakes – they were barely adequate back in their day, let alone with more power and more traffic on our roads now. The new calipers provide far more clamp force, while the big, vented rotors can expel heat much better than the original Torana hardware.
2. You should double-check caliper clearance on your wheels. Dummy-fit a hub, caliper and disc off the car to ensure everything will clear. Alternatively, Hoppers Stoppers has templates you can download off its website that allow you to do some quick maths to make sure the wheels clear your new brakes.
3. Once the vehicle is securely off the ground, remove the front wheels and the brake lines that run from the caliper to the chassis. The Hoppers kit comes with new lines, as the calipers are mounted in a different position.
4. Remove the original single-pot caliper from each side, then marvel at the new wheel chocks you just scored.
5a. Remove the grease cap, split pin and wheel bearing retaining nut, then pull the wheel bearings and old solid rotor off the stub axle.
5b. Clean and inspect the stub axle for damage or excessive wear. If your Torana still has dust plates, bin them now.
6a. Swap the stub axles from left to right so the caliper mounting points are on the back side of the stub axle. Before fitting the caliper adapter bracket, check that the new bracket sits flush against the stub axle.
6b. If it fouls on an unmachined part of the stub, clean the area with a grinder, but do not grind any smooth or machined areas.
7. The steel caliper-mounting plate needs to be attached to the stub axle through the original caliper bolt holes. Hoppers provides cap screws and spring washers to suit
8a. Grease the hub and wheel bearing sets that come with the kit, and install the inner bearings to the new hubs.
8b. Fit the grease seal on the stub axle, then slide the hub onto the stub axle and install the outer bearing, tab washer and castle nut.
9a. Don’t heave on the nut when tightening it; it should be tightened to the recommended preload.
9b. For tapered-roller bearings, this means you should allow a small amount of end float, as you’ll destroy the bearings if they are too tight. Reinsert the split washer and tap the dust cap on.
10. Slide the new rotor onto the hub and use a wheel nut or two to hold it in place. The wheel nuts are only required to hold the disc in situ until the wheel is ready to be bolted on.
11. With the bleed nipple at the top of the caliper and pointing upwards, fit the caliper to the bracket using two washers on each bolt – one under the head of the bolt and one between the caliper and the bracket. Spin the rotor on the hub to check it runs centrally in the bracket, as there can be variances in stub axles that can cause the rotor to sit off-centre. This requires shims or shortening the spacers to correct.
12a. The hose can then be fitted to the caliper, with a copper crush washer used on both sides of each banjo fitting.
12b. Fit the new hose to the existing hardline and replace the horseshoe clip to secure it.
13. Secure the brake line to the car using a P-clip and spring. In this installation, Hoppers Stoppers drilled a small hole in the top control arm lip to use as an anchor point.
14a. Test fit the front wheels to check for clearance to the brake hose and suspension, ideally at full lock in both directions.
14b. And try different suspension travel scenarios.
15a. Once clearance is confirmed, pull the front wheels off and bleed the brakes.
15b. Start with the brake caliper the furthest from the master cylinder.
16. Double-check pedal feel once the car is on the ground, then bed the new brake pads in. Don’t go randomly testing out how good your new brakes are, because you might find other motorists might not be able to stop in time!