PECM Issue 26 2017 | Page 67

AIRBACK BRAKE RETRACTION SYSTEM ® ost drivers are blissfully unaware that their disc brakes never completely release after use. As a result, brake pads are likely to remain in firm contact with the adjacent disc throughout an entire journey, regardless of the fact that they will have remained unused for the majority of this time. M The negative effect of this ‘drag’ is well known in the Automotive Industry and has been viewed, until now, as an acceptable compromise to this otherwise simple and economical brake system. For the vehicle owner the significance of this side effect is a reduction in performance, fuel economy (or range with electric cars) and reduced brake service intervals. Excessive drag can also cause over-heating and glazing of brake pads. CO2 emissions and airborne brake dust pollution is increasingly of concern for Governments, Health Professionals and Scientists worldwide. Many countries including the UK are now facing air pollution fines, for failure to rectify breaches in agreed air quality standards. With some 60 million plus cars produced annually worldwide and growing, this problem needs to be addressed now! At AirBack® we have spent the past six years developing systems that can effectively remove brake drag. The latest design reliably backs-off the caliper pistons after braking and then closes this minute gap just prior to the next application of the brake. Our latest patent pending design uses a micro compressor, the length of a matchstick, to reduce the pressure (relative to that of atmosphere) in the master cylinder reservoir. This has the effect of pulling back the brake caliper pistons after each brake application. Upon the prediction of a brake application, the compressor outputs positive air pressure to the reservoir. This has the effect of closing the gap between the pad and disc, in readiness for brake activation. The system is failsafe in operation as it has no direct effect on the vehicles braking performance - it merely creates a small degree of pad retraction. For those of you who are concerned about any contaminants entering the brake reservoir, there is an isolating diaphragm separating the brake fluid from the air supply. The benefit of the system is to substantially reduce the vehicle rolling resistance by up to 70% with potential fuel savings clearly evident depending on how you like to drive. For those with a sports leaning, the vehicle is likely to feel more agile and perform rather better. The effect of applying positive air pressure to the master cylinder reservoir can further benefit ‘Circuit Racing or Rally Cross’, drivers. Brake caliper’s can suffer forces that cause the slave pistons to retract from their normal position i.e. catching the ramped crown of a race circuit bend. The effect (known as knockback) is loss of brakes, which has hitherto been recovered by the drivers frantically pumping their brakes! The AirBack® system simply applies a pre-set higher pressure, activated via a momentary switch mounted on the steering wheel. So you can see that the AirBack® system has something for everyone! Trevor Mennie airback.co.uk Email: [email protected] Tel+44 (0)1435 872624