Mazda MX-5 Mk3 rear brake pad replacement

The MX-5 Mk3 Sport was Jeremy Haworth’s son’s pride and joy. Until there was an ominous sound from the rear.

There was a nasty rasping sound from both rear wheels of the MX-5 Mk3 Sport, so Dad’s opinion was sought. Despite being an old specialist in Alpine A310s and Renault Gordini 8s of the lightweight body variety, Dad was puzzled. But not lost.

Rear wheels off and it was evident that the rear pads were worn to the 1.5mm legal limit. Removing a pad showed that the inner edge looked different, with a duller, rougher surface providing another clue. The answer: Mazda’s Acoustic Brake Warning System.

Thin pads expose a change in fabric material, giving rise to a rasping warning sound that tells you new pads are needed. Be aware that earlier models used a spring plate or wire fitted alongside a pad to alert you to the wear limit. Mazda used a number of variations on this theme before having a moment of enlightenment and using the pad material itself.

The rest is standard procedure. Jack up the vehicle onto axle stands, remove the wheels, calipers and pads, clean off any dust and replace them with your brand of choice. All leading manufacturers match Mazda’s specification for acoustic pads.

Inserting the new pads and refitting the caliper is a straightforward reversal of the procedure outlined here, with no clips, springs, clamps or tensioners in this version. After taking up the initial slack by pressing the footbrake, you work the handbrake a number of times to reset the auto adjust within each rear caliper. Emergencies excepted, use gentle braking for 100 miles or so to bed-in the new pads.

Fluid check

You also need to ascertain whether the brake fluid reservoir level has been allowed to drop naturally as the pads wear and the pistons move out. If it has been topped up, as so many have advised for decades, setting the pistons back will restore the fluid to beyond ‘Max’ level and may cause an overflow. All manufacturers’ systems are designed to be at ‘Max’ with new pads and discs and at ‘Min’ with fully worn pads/discs. So there should never be any need to top up your brake fluid, although an unexpected drop should be investigated, unless brake failure has become apparent. This advice is not to negate a two-yearly brake and clutch fluid change to ensure the long and trouble-free service life of the hydraulics, but is made in recognition of the handbook advice to always keep the level at ‘Max’, even though you may have to siphon out and discard what you may have recently put in.