Sponsored by WORKSHOP MX5 Discs And Pads WORKSHOP MX5 Discs And Pads mazda MX5 brake discs and pads www.classicsmonthly.com for great classic tech This routine servicing task is well within the grasp of the DIY enthusiast. Here’s how to do it and save on labour charges. Words and photography by John Betts Workgauge rienc xpe e Exp erie nc e d Sp ec nn er e me So ia l i Skill REQUIRED Cost (Pounds) time (Hours) st Beg i R eplacing worn brake pads and discs is a very simple task and will transform your car if these products are past their best. All that’s required is a spare afternoon, some basic tools and a degree of common sense. Carrying out this work yourself will save a decent amount of money in labour charges. The work shown here was done on a Mazda MX5 – officially the world’s most popular open-top sportscar. This means there are plenty of examples around, and savvy classic car fans are finding ways of uprating the braking systems on a number of older classics using MX5 front discs and calipers. The Mazda is a great little sportscar with agile handling, above-average performance and well-balanced brakes – if they’re well looked after. Any car with worn or tired brakes will feel extremely spongy under braking and not inspire driver confidence. Here’s how to overhaul them. 0003 0050 essential tool Toolbox ■ Axle stands ■ Jack ■ Wheel brace ■ Sockets ■ Wire brush ■ Brake cleaner ■ Brake fluid ■ Brake bleeding kit Thanks to SMC Unit 1, Southview Buildings Southview Farm Burton Rd Heckington Sleaford Lincs, NG34 9QS Tel: 01529 460049 84 CLASSICS MONTHLY JULY 2010 Brake bleeding kit Item 37316 Price £9.64 Tel 02380 494333 For more information on the full range of Draper products and stockist details, visit www.draper.co.uk. www.classicsmonthly.com JULY 2010 CLASSICS MONTHLY 85 Sponsored by WORKSHOP MX5 Discs And Pads In the air Slacken the wheel nuts off a quarter of a turn and jack the car up. Place the axle stands under the jacking points on the sills and put chocks either side of the wheels that remain on the ground. MX5 Discs And Pads Tech tihp ess ave acc on’t If you d ke bleeding kit, to a bra and length of r a jam ja ber hose will clear rub the job. do Start 1 2 WORKSHOP Gain access Remove the road wheels then undo the 14mm bolt at the bottom of the caliper. This has a long shank that the caliper slides on, so once it’s undone you’ll need to pull it out fully. 3 QUICK TECH Changing brake fluid Out the way You can now raise the caliper up and slide it off the top pivot pin. Place the caliper out of the way on the lower wishbone, ensuring that the flexible hose isn’t being held under tension. Brake fluid is hygroscopic – it absorbs moisture, reducing its effectiveness. Remove as much old fluid from the reservoir as possible using a syringe or similar. Top up with fresh fluid and pump through as if bleeding the brakes, but continue until clean fluid comes through. Repeat on all four corners, remembering to replenish the reservoir regularly. 10 Push the piston Gently push the piston back into the caliper, making sure the fluid in the reservoir doesn’t overflow. Install the caliper on to the bracket and secure with the lower pin. 11 Nice pair 13 Slacken adjuster If you have put any dirt or grease on the disc, give it a final clean. Regardless of the condition of the opposite side it must also be changed – pads and discs must always be replaced in pairs. REARS job 1 One-man A self-bleed kit aids solo bleeding or brake fluid replacement. Attached to the bleed nipple, a vacuum is created by the pump. Use an 8mm spanner on the nipple and the fluid will be drawn through. 4 Time for change There are different setups of pads and retaining clips on the MX5 depending on the model year. Make a note of what’s fitted, then remove them. The pads shown aren’t that old but the discs were badly worn and the pads have uneven wear. 5 Bracket off I’m replacing the pads and the discs at the same time, so the caliper bracket will also have to come off. Undo the two securing bolts with a 14mm socket or spanner and lift off the bracket. 6 Remove disc With the caliper bracket off, there’s now nothing holding the disc in place so it can be removed from the car. Take care that it doesn’t drop off as the bracket’s removed. 12 kit? Try this 2 No Use some clear pipe and a Work carefully Before the rear brakes can be replaced, you need to slacken the piston adjuster. Undo the 14mm bolt on the back of the caliper, taking care not to lose the small copper washer when the bolt’s removed. container to collect the fluid. Have an assistant depress the pedal as you open the nipple, then lock it off before they release the pedal. 7 Clean it up Your new discs will have a protective coating, so they’ll need cleaning before you can fit them. Use brake cleaner and a clean cloth for this. Ensure your hands are grease free and avoid contact with the braking area on the disc. 86 CLASSICS MONTHLY JULY 2010 8 Refitting disc The new disc can then be located on the hub and the caliper bracket can be refitted. Refit the bolts – you’ll need a torque wrench to tighten the 14mm bolts to 36-51 lb-ft. 9 Copper grease Fit the clips back into the caliper bracket and install the brake pads. Apply some copper grease to the contact areas, making sure it doesn’t come into contact with the braking surface. Fit the spring clips into the ends of the pads. Tech titap es ct surfac con Coat all per grease only t with cop tting to preven before fi ak squeal. bre up 3 Topping Keep the reservoir topped up to prevent air entering the system. Draw new fluid through until clear fluid appears without bubbles. Pump the pedal to ensure it feels correct before test driving. www.classicsmonthly.com You’ll then need a small Allen key – mine was a 4mm but yours may be different – to undo the adjuster screw. Turn it anti-clockwise until it stops, keeping an eye on the reservoir fluid level. 14 Cover up As with the front, the caliper pivots at the top and has a securing bolt at the bottom. On the rear, there’s a small plastic cover on the fixing bolt. Remove this and place it somewhere safe. 15 Remove bolt Using a 10mm spanner, undo the lower retaining bolt. Once the threads are fully undone, pull the bolt out of the caliper. I needed to use a pair of pliers for this because it was quite stiff. JULY 2010 CLASSICS MONTHLY 87 WORKSHOP MX5 Discs And Pads www.classicsmonthly.com for great classic tech 16 Swing and slide Swing the caliper upwards and slide it off the top retaining pin. This should be cleaned once the caliper has been removed. Place the caliper safely out of the way on the lower wishbone. 17 Extract pads I had to use a screwdriver to extract the pads – they’d become stuck. Now remove the disc. Once off, use brake cleaner to clean the area. If you need to use a wire brush or similar, ensure you wear a suitable face mask and eye protection. 18 Stay clean 21 Check adjustment Clean the new brake disc as before and install it on the car. At the rear, you don’t have to remove the caliper bracket in order to fit the new discs. It’s always a good idea to clean your hands or put new gloves on for this stage. Tech tilapce brake rep Always iscs in pairs. d r o s d a alanced p evenly b ntial. , th o o e Sm s s e is braking 19 Pads in Apply copper grease to all the contact points, and install the new pads into the bracket along with any clips that are fitted. Different models seem to have different setups. Finish 22 And repeat If you’re happy with the adjustment, fit the 14mm cover bolt and clean the disc once more. Repeat the process on the other side. Job done. You’ve just saved yourself big money. 88 CLASSICS MONTHLY JULY 2010 20 Grease and drop Slide the caliper on to the top pin after applying a smear of copper grease to it. Drop it down over the new brake pads. Secure with the 10mm bolt, torqued down to 25 lb-ft, then fit the small plastic cover. Using the 4mm Allen key, turn the adjuster until you can feel the pads hit the disc (it’ll become harder to turn) then back it off a third of a turn. Pump the pedal a few times and check that the disc can still be turned easily. CM says… Replacing your classic’s worn discs and pads will improve the car’s braking efficiency, returning it to its original state. There will be reduced pedal travel, and if the brakes are bled and fluid replaced, the pedal will also feel less spongy and more responsive. Place the axle stands under the jacking points on the sills, and be sure you’re working on solid, even ground. Chock the wheels that remain on the ground to stop the car from rolling. Brake dust can be hazardous so use a mask when cleaning parts and don’t use compressed air to remove dust. Once fitted, the new discs and pads should be sympathetically bedded in for the first 200-300 miles. Avoid harsh braking if possible and watch for judder and squeals. Recheck if necessary.