- My model of MX-5 is: MK4
- I’m based near: __Coventry
- I’m looking for technical help or recommendations on: __Brake fluid change
My 2018 MK4 RF needs its brake fluid changing . Should I do this myself (without any help) or would I be wise to let a garage do the work. I am used to changing the brake fluid on my old bike but not on a car.
If you’re confident do it yourself, replace fluid in the master cylinder first with a syringe or similar then open each bleed nipple it turn connect a hose and bottle and gently pump the fluid through using the brake pedal, 10 pumps each is about enough. Same procedure as you’re probably used to really.
Good advice from Robbie.
You can get kits, but never bothered with those as the wife is free.
As said before, make sure you screw the cap back on after topping up each time before pumping the pedal as it will spray every where!
I know from experience and something you only ever make the mistake of doing once. 
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And while you are down there check each of the calipers over and relubricate where necessary. Presumably the ND calipers use slider pins like the earlier ones?
When I had my Brembos fitted, just pumping the pedal didn’t seem to work. We had to use a tool to suck the fluid from the caliper (the pump from the MC didn’t work as it’s got a push fit type cap, not a screw on one).
If you are confident in changing the fluid then go ahead and change it. Also bleed the clutch as well as it uses the brake reservoir so don’t go too low before putting in new fluid. I can recommend ATE Typ 200 brake fluid.
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I watch a very interesting video on utube from the I think it’s flying miata .
He bled the brakes as we all do but at the end he did a couple of variations. His preferred procedure was to just crack open the bleed nipples & let them bleed with gravity. He did say it takes longer but he reckons it’s the best way!! Anybody else seen this video & what do you think???
This is covered on the Mazda services - let them do it - saves any issues - and remember service history is worth every penny.
A self serviced owners club car can be worth every penny too come sale time, or even independent garage serviced. Just keep the proof👍
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Just thought I would share this.
I know the topic is regarding the ND, but the principles are the same.
I renewed the fluid on my 3.75 last weekend and decided it would be prudent to bleed/change the fluid in the clutch system this time.
What a nightmare that turned out to be!!
All going well, then the clutch pedal just went loose with no pumping whatsoever.
No matter what we did nothing and actually thought the master cylinder was gone…….
Not giving up, took the master and slave cylinder’s off drained and restarted the process.
Actually getting them off was quite easy.
Just need a long reach 12mm socket.
Reassemble was a tad awkward (bruised side and ribs 
) with the adjustment rod and actually discovered that if yours is okay you don’t have to touch it at all.
Quite quickly the fluid got to where it’s supposed to go and hey presto all sorted.
I reckon that somehow the system got an “airlock” and just would not clear using the pedal method.
So having said I have never bothered with a pressure bleeder before, just might change my mind now!! 
If you do ever go for the pressure bleeders that push the fluid through never never never fill the container with brake fluid. Just use it dry, slightly more time consuming but so much safer.
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From experience perhaps. 
Yes indeed, on my new Caterham Superlight R build I managed to spray brake fluid all over the body, engine bay and interior below the pedal box. Absolute nightmare, I was prancing about like a headless chicken in the dark. Fortunately common sense prevailed and I had the hose pipe out and just kept washing it away. It took a few hours to mop up the water but I survived to tell the tale and hopefully preventing someone else making the same mistake.
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I have a ND 6 years old that has only done 6,000 miles.
It is due to get an oil change.
Should I change the brake fluid? Will it matter?
If it has not had one at all then yes I would. Your garage should have a ‘water content’ meter to help you decide.
I do all our cars every 3 years, my meter always says they are still OK but for the sake of £10 of fluid and bit of time I feel better.
Do garages actually do a water test, or just say it should be done anyway (and here is the bill)?
It has done about 1,000 miles in recent years because of Covid.
Brake fluid needs to be replaced on time rather than on mileage, as it is hydrophilic (absorbs water from the atmosphere). Even if you had only done 1 mile it would still need to be replaced. Most manufacturers recommend every 24 or 36 months.
No they won’t if they think there is a possibility them get some additional income, but they should have the equipment to test it if you ask.
If you do not know when it was last done then have it changed just for peace of mind.