Unlike your method we are trying to find out if there is a trend in disc brake temperature that will show up as a difference in temperature between the two different front discs.
That way you get it fixed probably before the brake seizes with some luck.
YOU CAN GET A BURN BY TOUCHING THE BRAKE DISC well before the caliper piston has seized on therefore an IR thermometer as the OP has found online, is the preferred method of recording temperature unless you are offering to visit the OP every day to use your Asbestos fingers to check the disc temperature.
The Ezibleed is a very good tool but you must not fill it with brake fluid. If you use it dry any partial leaks will only be air. You have to keep your eye on the fluid level in the master cylinder and keep topping it up but that is a small price to pay for safe, easy, one man operation.
I had exactly the same issue on my 5 with the passenger front sticking. I didn’t realise it was sticking until i put her in for MOT and the garage(who are very reliable)showed me and freed it up. It got the car through the MOT but on a longer trip out there was a sreeching where the brake had stuck again, so because the garage freed it up doesn’t mean it will last long if there is an underlying issue.
I decided to remove the caliper and replace the piston and seals (it did not go well!) so i decided to replace both front calipers which was so easy to do i should have done it in the first place and i am no expert.
So, my advice is to replace the caliper as a minimum. Both in my opinion is best as you can practically guarantee the other will play up. Got my replacements from MX5 parts who were excellent.
Remember, this is just my opinion and you will get plenty of them here!
Good luck…
Well I’ve not not had the infared thermometer delivered yet, but yesterday after a gentle drive the left wheel was DEFINITELY a lot hotter than the right so have just booked it in for a caliper change. Will probably get both front ones changed unless they’re completely sure the right-side one is fine. Not sorry to have ordered the thermometer though, it’ll be useful in keeping an eye on the brakes (and presumably other things) in future.
Again, because I’ve only just got this car (after it sat in a barn for 6 years…) and am not sure what other underlying problems might be lurking which could be beyond my skills/knowledge, I’m going to let the garage deal with this for now - but it’s good to know all this stuff can be done in the driveway, and will definitely be up for tackling any further problems like this in the future. Sounds like it might be worth me overhauling the rear calipers for example, even tho these currently seem fine.
Can’t wait until this is sorted - I keep meaning to take it in for a full geometry wheel alignment, but keep having to cancel due to various bits mechanical work that needs doing!
When your caliper sticks it’s obvious to anyone there’s a clear temperature difference. The thermometer will come in handy I’m sure, but not needed for this. If the brake fluid hasn’t been changed since before it spent 6 years unused, this is a good chance to flush the system through. I’m sure the garage will do it for a minimal charge.
Eddie, take a chill pill and calm yourself down mate. No one was suggesting touching discs. As you can see from the OP’s last post, the temperature difference was obvious. One wheel hot the other mildly warm. You don’t need to know what the temperature is, or record it.
Just dropped it off at the garage, and not a moment too soon it seems… haven’t driven it since noticing a definite difference in wheel temps a week ago, but after the half-hour journey to the garage the front left disc was about 300C. Other front wheel was about 130, rear wheels both about 80. Thing is, aren’t all these readings a bit too high for comfort? I checked the courtesy car on returning from the garage, this was 30C rear wheels, 50C front - which sounds more in line with what I’ve read should be normal. Hope rear calipers not on way out too… tho I’d think it’d be a bit unlikely that they were both sticking to exactly the same degree (i.e. same temp on either side) - they’re 1.8 Sport big brakes if that makes any difference.
As for the argument over the infared thermometer - yes, if there’s a real problem, I agree it’s pretty obvious that one wheel is a lot hotter just by standing close to them! However, if I’d had the infared thermometer sooner, I could probably have diagnosed this problem a few weeks sooner, at the stage where the wheel felt very slightly hotter, but not so hot you could be 100% sure it was different just by touching it.
Are you sure you’re not confusing centigrade with Fahrenheit? Are you measuring the wheel or the disc temperature? Because the temperatures you say you have on all 4 wheels would burn your hands. As for diagnosing the problem sooner? I doubt you had a problem much before you first noticed. When they stick, the problem gets obvious quickly. You knew there was a problem 2 weeks ago when you first posted, but hoped it was nothing to worry about. I suspect your temperatures at the wheel are a Fahrenheit reading which would be fine. Don’t get too hung up on the temps, a simple touch of the wheels once in a while to monitor them is all that’s needed. If those readings are correct at 130 centigrade front and 80 rears, then you probably need a complete overhaul of your braking system because those are far too hot.
So the front calipers now changed, all pronounced OK by garage, and brake fluid changed. Unfortunately I’m now off the road again with a snapped drivebelt… will be replacing this myself in next few days and then will definitely be keeping a close eye on brake disc temps! The two times I did get a chance to measure temps tho after caliper change and before belt snapped, the discs were at about 70 at front, 60 at rear. So nothing in the 130 or 300 range I found before, but still sounds a bit hotter than it should be from what I can gather?
Anyway, will have to get back to this one once I’ve replaced belt, as if something’s causing ALL discs to get overly hot, I’ve no idea what that would be…
Thread resurrection because there is very useful information here for owners with possible brake problems.
While driving my NB MX-5 recently I found the car was slowing down more quickly than it should while off throttle. I put the windows down and noticed a horrible burning smell, checked the wheels and found the front passenger side one was so hot that I could only touch it for a split second, while the front driver side wheel was only warm.
There had been no audible sound from the seized brake while driving and I only knew about checking the wheels because I run another old car that had a sticking/seized brake piston and one wheel became so hot that it set off the tyre pressure sensor alarm on that car.
The recently inherited NB passed its MOT in Aug 2019, but the August 2018 service invoice noted: “Check for front brakes binding - remove front brake pads, clean and lub [sic]”.
I took the car to my own usual mechanics today and it turns out the pistons on both front brakes were not returning properly, resulting in damaged discs and pads. £466 including labour and VAT for new front calipers, discs and pads. 1.8 hours labour at London prices.
Calipers (CAL9071L and CAL1766R) cost £95.28 each including VAT. “Genuine Mazda” front calipers on MX5parts cost £179.95 each. That is quite a price difference, so I am guessing my garage has not used OEM calipers, although they claim to always use parts of “OE standard”.
I’ve had exactly this issue on my NC - front passenger side brake binding. I noticed the wheel centre badge was missing at the weekend, then on a short motorway drive Monday felt some vibration. When I stopped it was obvious from the smell that something had got overheated, and I could see the disc was blue.
The caliper has been off, cleaned and greased but this didn’t resolve. The flexi-hose seemed constricted so that’s been replaced too. Theres less friction now, but it’s still not right.
So - either the caliper needs replacing (although the guide pins seem perfectly free & piston moves in and out OK), or there’s a problem in the ABS pump/modulator. Are there any known issues with this?
Not an uncommon problem on all older cars. I know you can get rebuild kits but what a faff! And it’s brakes we’re talking about.
I’ve rebuilt callipers before and its only ever temporary.
Always change them, as with pads in a pair.
I seem to be suffering the not releasing caliper front left hand, not sliders checked cleaned and then replaced any way, not caliper bought new but mechanic released pressure via bleed and piston returns fine, not hose, disconnected and calliper piston returns. so it looks like an ABS pump problem, as per above is this a known problem?