Hi all,
I’m sure you all suffer this problem too. Do you find that after a few weeks of use, the handbrake doesn’t work, is all the way at the top and rear doesn’t brake much? The pistons need winding in to re-adjust them.
Never owned a car that needed so much brake attention so frequently. Are there any upgraded calipers? I heard Volvo calipers from specific models are a direct fit?
Just get MX5 recon callipers from Autolink.
Yes, I’ve found this “characteristic” with the two NBs in our family. The sliding pins holding the caliper are prone to getting a bit sticky. This can result in fairly quick pad wear because they stay in contact with the disc and the caliper doesn’t “self adjust” to compensate for the wear.
Further to Nick’s comment and just to clarify - this is NOT how the rear calipers should work. Once adjusted correctly, they should be fine. Full stop. Until the next time that you back off the adjusters to remove the pads - then you’ll need to adjust back up when finished. But they certainly shouldn’t need “so much brake attention so frequently”.
Just try a replacement pair of standard calipers.
Please do not assume that your brakes requiring frequent adjustment is common, a well maintained MX5 car does not require this. It usually means the internal handbrake mechanisms are on the way out or the brakes have not been adjusted properly.
Just to confirm.
You have loosened the handbrake cable at the handbrake lever in the car so there is no cable pull at all either of the handbrake mechanism at the calipers and you have checked that, please answer yes or to this question.
You then undone the 14mm cover bolt on each rear caliper and tightened the 4mm allen screw, did it turn they can seize.
Again yes or no to doing both sides.
You checked the mechanism was free at the each caliper end and using a lever you could put the handbrake on manually by moving each of the operating mechanism that the cable goes into, yes or no.
You turned each of the 4mm allen screw until each caliper stopped the hub turning, you then put the wheel back on to check that the wheel would not turn. Yes or no and confirm this was done with the wheel actually on the hub and you are not turning just the hub.
You then loossen each allen key bolts a quarter turn to unlock the wheel but there should still be a bit drag. Again yes or no.
You then replace the 14mm cover bolts. yes or no
The three handbrake cables are free to move, you then went back to the handbrake lever and tightened the handbrake cable inside the car until the rear wheels were both locked at about 7 clicks of the handbrake mechanism. Yes or no.
The vast majority of people do not follow each step advised here especially putting the wheel back on to confirm that the wheel rotation is locked and will lie to cover up for only doing a part job if you ask them the questions I have just asked as that procedure is far to long for them.
They then replace with new calipers and have the same problem.
It sounds to me that you have a procedure problem rather than faulty calipers.
I assume the disks are in good condition and there is at least 8mm thickness of the disk and say at least 2 mm thickness on each pad.
A very good post on how to adjust the rear brakes. It cannot be emphasized enough that the handbrake cable needs to be loose, before adjustments are made. To check that the cables are slack, look at the lever arms on each caliper and they should be hard against the back stop.
Hi
Om my mk1 l found the right hand rear over heated but this was after a long run, but allways us a thin coat of copper slip on the slide pins cured the over heating problem l also installed better quality brake pads all round less heat generated and less wear and brake fade.
Never had the problem the OP suffers and as Eddie describes the correct procedure well. I would add, then go for a test drive applying brakes of course then re check the brakes for adjustment/free play. I only had to tweak the adjustment on one caliper once as it was dragging more that side, takes an extra few minutes.
Nice post mate, thanks.
Calipers were bought new back in July time, as one of the Allen screws had rounded in the old calipers. These are the ones I bought https://www.ebay.co.uk/itm/Mazda-MX5-MK1-MK2-Rear-Brake-Calipers-Pair-Brand-New-Units-/222746004135?hash=item33dcb24aa7
Handbrake cables are all brand new too, all 3, so the mechanism should, in theory, work perfectly.
The nut at the handbrake lever side (under the lever) is at the bottom, so fully slackened. The brackets on the caliper are on the stops, the 4mm Allen screws are turning easily, locking the wheel, I then back off 1/3rd of a turn until wheel rotates.
Where I may be going wrong is the nut adjustment inside the car, I’ve always kept the handbrake about 3/4 clicks and used the 4mm Allen screws to adjust that rather than the nut inside.
I just feel the piston is not self adjusting as the pad wears. After a trackway my handbrake goes from 3/4 clicks all the way to the top, and won’t work at all.
Those calipers look like the bargain of the century…or crap. If you have everything else right and still have problems I’d look at changing those. On second thoughts, at that price I wouldn’t take a chance, I’d throw them out and start again.
But handbrake adjusted at 4 clicks will lead to a lot of wear on the pads and the need to adjust more often.
During my recent refurbishment of everything to do withe brakes, except the brake cable from the hand brake to the parking brake compensator, I bought and used these calipers. You do get more for your money too. They have been OK for me up to now, but I did grease the slides and every thing else that should be greased as well. With these you also get the angle brackets which I didn’t get with other makes of caliper. All I would say is this, take these brackets off the calipers and check one against the other to make sure they are as near as possible the same angle. I say this because the brackets that had been on my car since new, I guess, where off angle to each other by about 8mm which caused me lots of trouble trying to adjust the brakes and getting the compensator to be at 90 deg to the brake cables.
If you feel the calipers are not operating properly then use the 12 month warranty that the seller offered.
Not a bad shout l Think!
but back to the original question, are there any other calipers that would be an upgrade? Volvo twin pots I heard?
Unbalancing the braking by installing different ‘upgraded’ calipers and increasing the braking effort at the rear of the car is unnecessary and likely to be a very bad idea. Although the ABS will do its best to compensate additional braking effort at the back is likely to make the car unstable under hard braking. Far better to put the effort in to getting the originals to work correctly.
Agreed, however having come from a karting background and purpousefully biased my old golf gti towards the rear, I much prefer the handling characteristics of it, allows me to get the car turbed in before corners (On track).
I have to say they look the most un-new new calipers I have seen and if the picture is correct the copper washers look properly second hand. I would suspect the calipers not working.
It’s not front wheel drive, over braking the rear will get very undesirable rotation on the car ahead of the corner. You need to push it out, not pull it out and there is a great deal more mass than a Kart. You will just be totally compromised in corners and likely be accused of drifting deliberately and kicked off.
If there is one caliper not self adjusting all you have to do is check the equalizer it will be obvious which one is not adjusting when the parking brake is applied.