Hi Guys My 2010 MX 5 Mk 3 ,due to very little use (only 4000 covered so far) has suffered as a consequence in that the brake discs especially at the rear are badly pitted,MOT advisory issued with indication that change will be required next year.
Would appreciate knowing if there is any available info on how to carry out change and possible pitfalls.I have done tasks such as this and larger on older cars,but gather from general chat that callipers especially at rear can be tricky…from questions asked among MX5 drivers it would appear the new Hayne’s manual is not up to scratch for latest models, general reviews on line do not appear to rate it either, so am hoping Forum can assist, either with instructions or link to PDF or similar…Thanks
Many thanks for reply as that was/is exactly what I am looking for. Unfortunately at the moment when I attempt to download info I am getting message (Do not have permission to download file")
Hi, yes, quite straightforward if you’ve done similar brake jobs.
Caliper and carrier off, disc retaining screw on fronts (none on rear) may need an impact driver, then discs come off easy enough.
Single piston calipers front and rear on slider pins. Clean and lube pins with red rubber grease and pad edges and backs with copaslip or ceratec.
Return the pistons, front with a G clamp nothing tricky. Rears need to be pushed and turned at the same time so get the Laser tool from eBay, Halfords etc. It takes some force and messing with a screwdriver or similar will probably end with a split boot or hand.
When returned the rear piston slots need to be aligned perpendicular in the caliper (straight and 90 degrees to it) so the pip on the pad goes in.
Handbrake is self adjusting. Nothing to do other than make sure the handbrake lever in the car is set down fully to off, and the sprung cable lever on the caliper is fully returned to its off position when refitting the caliper.
The handbrake lever adjustment should be correct after a few pedal presses and applications. If the cable needs adjustment it’s a nut under the handbrake lever gaiter in the car.
Open the bleed screw when returning the piston so as not to force old fluid back up through the abs unit. Then a final bleed and job done.
Allow the day. I did mine over 2 days as I painted the stoneguards whilst the discs were off and changed the fluid as well. Good luck.
As you indicated, the pitting is due to lack of use and how you store the car. At a guess, I’d say the car is left in the open when not in use, in which case, all unprotected metal parts will rust.
If you intend using the car on a more regular basis during the next year, you may well find that the brake pads will polish out the pitting. (at least enough to get through the MOT). Otherwise, don’t change the disks until next year, or you’ll end up with a years worth of rust on brand new disks.
A lot of people think that by not using a car, they are preserving it, when as you’ve found to your cost, this is not always the case.
To be honest it will probably pass next year with an advisory, unless they are realy worn.
I had to change a rear set on a MK3.5 at 19k miles due to rust but my own car 11.5k miles four years old Cornwall and then 18k so 29.5 kmiles in 2 years Aberdeenshire garaged and they were starting to loose their bright smooth finish but were still above the minimium thickness.
many thanks to you all regarding disc problem. Its not so much due to preservation of the vehicle, more due to family needs. We have elderly (very) inlaws,one very large dog, plus my kayak for which we use Citroen Berlingo multi space, consequently beloved MX5 tends to get little use.
Equally Due to currency crisis euro wise,we have also for the last few years given up on our trips down though France to Lescala in Spain,as last time the cost of living in Spain was ridiculous (but that’s a another story)
However all of your input has been most helpful, and it is possible as stated that they may get through next years MOT, plus I shall attempt to get the car on the road more often and polish the discs (could do with a rolling road).
Its always a pleasure being a part of this Forum as the help and info received is second to none so again, with sufficient advice gained to enable me to carry out task if necessary my thanks
my rear discs were really bad and yet she had passed the mot with an advisory on it just days before , i have changed both discs and pads on rear , well my mechanic did lol , he said rusted discs could well get through an mot which surprised me as only a small area remained bright metal , my car will be in the open as well unfortunately
Yes they test on brake efficiency so long as there are no cracks but it can be up to the examiner to pass/fail or advise if they look bad.
It’s nearly always rear discs with a rust problem. MX5 is a light car and the rear discs do very little work (if they balanced them to do more the car would be in danger of locking the rears and spinning if applied in a bend for example). Have a look at a Merc or other large car or an auto car (which tend to use the brakes more) and you’ll see they are clean.
Keep the rears clean by applying the handbrake gently a couple of times for 100m or so on a clear straight road at about 30mph. Keep an eye on the rears and do this the minute you see rust across the disc. Always do it on wet mornings and after washing, never park the car up with wet brakes, once the rust is below the disc surface it’s very hard to get rid of
We’ve just had this as an advisory (or at least a mention) for ours- I will check what the sheet says tonight and see if it is something they can bring up.
I’m hoping the wife will allow me to change them myself- however it’ll be my first real bit of car repair, I hope it’s not too tricky.
Thats SO true , noticed a little rust already on new rear discs ! ^^^that explains it thanks , fronts are immaculate of course ^ , im very light on brakes generally with cars mayb too light ,
Have you tried the italian tune-up approach? Something my friends garage recommended a couple of times on the basis of “If I test it with the discs in that condition I may have to fail it - go and drive it around a bit and use the brakes a lot while I have a cup of tea, then bring it back”!
Seriously though the discs will rust overnight if it rains, esp if the rain blows through the wheels onto the discs, and if left (esp in winter if there’s a few dabs of salt on 'em) you can get some pitting, So keep using the brakes, especially just before the MOT. A few miles usually does it.