Is there a guide for brake fluid change?

[New Duke]

Since a trackday on Monday my brakes have lost a lot of friction. Specifically it feels like the rears are doing all the work.

From the outside the pads look to have loads of meat on them, but I'll take them off for inspection and re-grease the pins too while I'm there.

I'd defintely like to renew the brake fluid though. It probably hasn't been changed for years. Is there a guide somewhere like the excellent discs and pads guide? I had a search here but couldn't find one, just related threads like Warpc0il's detailing potential tool aids and some regarding quantity and fluid type.

If there's no guide:
- Does anyone know the diameter of the bleeder valves so that I can source the right tubing? I assume the R3 has the same bleeders as the S1?
- Are there any RX8 specific pitfalls/quirks to be aware of?
- If the car has been using DOT 4 (no idea if it has), then once drained can I refill with 5.1 without any intermediate flushing process?

[Freeman38]

Why not get a bleed valve tube which has a flexible end?
I use one which comes with a pot on the end to capture the old fluid. One man brake and clutch bleed tool they use to be called. Also get a brake spanner or similar a 3/4 spanner which grabs more of the hexagon faces than a normal open ended spanner. Failing that use a ring spanner if you can get it in there.

Fluid there's not much benefit to DoT5.1 use a good quality DoT4 like ATE super blue. This use to come in two colours Blue and gold. I would use Blue first change then in a couple of years when you come to change again use the gold makes it easy to know when you have all the old fluid removed.

[SeriousSam]

Seems like an obvious guide that's missing, reckon I might try and grab some pictures and write one up the next time I do mine - should be some time in March. Here's the basics.

You'll need some spanners, I find ring spanners work well - 8mm and 10mm should be standard, but I've had to use 9mm and 11mm in the past. You'll also need some tubing and a pot to catch the old fluid in - I use a vacuum test kit, which came with the right size of tube and a suitable reservoir, along with a vacuum pump - not bad for thirty quid. Also safety glasses - brake fluid doesn't do any permanent harm to your eyes if you rinse it out, but it doesn't half sting! Obviously a jack and axle stands to prop the car up while you're working on it, and a torque wrench to tighten the wheel nuts after you finish. And you'll want an assistant to make the process as easy as possible - this can be done solo, but I've had trouble using one-man methods, where the two-man has never failed.

In terms of materials, if you're doing a full flush get yourself 2 litres of your desired fluid, and make sure you've got some paper towels and brake cleaner on hand for the inevitable spillages and drips - brake fluid is a handy lubricant, and you'll be wanting to clean it off the discs before you drive.

1. Jack up the car - either the whole thing or the rear to begin with, place on stands. Remove wheels.
2. Open bonnet, take brake fluid reservoir cap off, prepare to top up with fresh fluid regularly through this process.
3. Place assistant in the driver's seat, then either wind the windows down or open the doors - you need to communicate.
4. The accepted order is to start with the corner furthest from the master cylinder and work inwards. That makes the sequence rear passenger, rear driver, front passenger, front driver, master cylinder (if applicable). I also tend to start with the master cylinder to ensure new fluid is going through the whole system and no bubbles are being pushed through from the top - but the R3 has no master cylinder bleed nipple as I recall, so that complicates things somewhat.
5. Remove bleed nipple cap if present. Pop your ring spanner over the bleed nipple, then your tube over the end of the nipple, place the other end of the tube in your pot or fluid receptacle (good word that, far under-utilised in the modern vernacular. I digress)
6. Open the bleed nipple, tell your assistant to push the brake pedal to the floor. The word 'Down' works well for this. Observe the dirty old fluid flowing though your tube, possibly with a few air bubbles in it. Marvel at the wonders of how this stuff ever stopped your car.
7. When pedal hits floor, assistant tells you so. Again 'Down' works well here.
8. Close bleed nipple, tell your assistant to release the pedal. 'Up' can be employed to good effect here.
9. Assistant acknowledges that the pedal has returned. Again 'Up' seems appropriate.
10. Repeat the process until the fluid coming out of the nipple is clean and has no bubbles in it. Be sure to continue checking the level in the master cylinder regularly, I tend to check it every 5 pumps. Top up as necessary - the last thing you want is to let the master cylinder run low, because then you'll push air into the lines and need to bleed that out.
11. Once you've finished each corner, move on to the next in sequence and do the whole thing again. Once everything is properly bled out and fresh fluid is in the system, you should find that the brake pedal feels very stiff when the engine is not running - it should move down a short way, then bite, then not move any further once you apply full pressure. If it feels spongy, you have air in the system and need to bleed that out. If it feels stiff but moves slowly to the floor, you have a leak somewhere, so look for drips

And that's pretty much that. Once you've got it down, you can bleed the entire system in about half an hour, it's not too bad. Just be methodical the first time, and be careful not to over-tighten the bleed nipples - they can be crushed, which is not good news. They need to be tight enough to not allow fluid through, but not so tight as to damage them. You'll feel that out as you go

And to answer your question, DOT 5.1 and DOT 4 are compatible, so there's no special process needed to flush the old stuff out - just have a lot of fluid on hand to make sure that what's coming out at the end is indeed fresh new fluid and not just clean, old fluid. You could use a syringe to draw most of the old fluid out from the reservoir before you start, that will save a few minutes. But since you're changing the fluid, you'll also need to bleed the clutch, which is a pain in the arse thanks to difficult access and significantly less fluid displacement with each pump. Patience is key with that one.

[bigpete8]

Couldn't you save a load of time and syphon the reservoir?

[Ainmhidh]

Did my R3 a year ago with the help of a friend, whilst swapping out the disks and pads (not necessary to do this at the same time though, obviously!)
some thin silicone tubing (from this http://amzn.eu/iMXQRRR) over the bleed nipple down to a jar / old fluid bottle, small (10mm?) ring spanner on the hex part, pressure on the brake pedal, crack the bleed valve until the pedal bottoms out, lock off the valve, let pedal up and repeat until clean fluid comes through. Repeat on all corners.
The only warning I'd give you is the Min line on the fluid reservoir REALLY means it! We managed to suck in some air by letting it get to the min line (not past it, just to it) and it took another litre of brake fluid to flush them all through.
apologies if I'm teaching you to suck eggs - just realised you didn't actually ask for a talk through - just any RX8/R3 specific vagaries!

[SeriousSam]

Couldn't you save a load of time and syphon the reservoir?

You could use a syringe to draw most of the old fluid out from the reservoir before you start, that will save a few minutes.

Yep

[Nickp47]

Sam, not only is your guide useful for someone like myself who is yet to perform this task but wants to learn, the helpful instructions of how and when to employ the words 'up' and 'down' and their suitability for the task gave me a good chuckle, thanks!

[SeriousSam]

Happy to oblige

[PaulAV]

This you tube video might help (its on a left hand drive car so when he says passenger he means driver side) also if you can suck out the fluid from the reservoir first it'll speed things up, also you can use a purpose made pipe with a bung in the end and a split in the pipe which acts like a valve

[warpc0il]

Don't forget that the clutch shares the same fluid, so you should also flush the slave cylinder to.

Sent from my SM-G800F using Tapatalk

[PeteH]

Great guide. I'll add three comments:
1. Having a six sided socket (ideally long reach) is really helpful for cracking off the bleed nipples. Crack them off, then nip them up, then put your normal ring spanner on for the actual bleed process. If you round off your crusty old bleed nipple then you have a world of pain.
2. In this modern age we should probably bleed from the corner that is furthest from the ABS unit, since that now has the longest pipe run. So we should probably start with the rear driver's side.
3. I always end with another bleed of the master cylinder. It's amazing how much air can stay trapped in there.

[SeriousSam]

All we need now is some pictures and we've got ourselves a top guide! Thanks for the additions gents, always helpful - I'll see if I can get the clutch bled out when I next do it, just to add that in for completeness.

EDIT: To add to this, is there a procedure for purging air from the master cylinder on cars that don't have bleed nipples?

[Harrizone]

Also, isn't the brake system biased and arranged in such a way so that they diagonally remain operational so that the correct way is for the off side rear and then the nearside front then the nearside rear and offside front be bled Just a thought, although convention says the longest first and then the decreasing distance from rear to the master cylinder would be the way to do it.

[New Duke]

Sometimes you find that air gets drawn in around the thread of the bleed nipple, which can make the whole process take much longer and use more fluid. To avoid this and to help prevent the nipple seizing in the future, you can use a couple of turns of PTFE tape on the nipple thread.
Note that it's not the thread that seals normally but the pointed tip of the nipple into the tapered seat.
If you over-tighten the nipple then the hole at the side gets deformed and the point bends slightly, which is what makes nipples weep.

Pre-2006 cars have a nipple on the master cylinder, which is handy to remove any air (or stale fluid) from there.

With or without this master cylinder nipple, you can improve the pedal feel after a change by pointing the car down a steep slope and holding the brake pedal down firmly for about 30 seconds with the engine running. This encourages any tiny bubbles in the fluid to coalesce and gather behind the master cylinder piston. Release the pedal slooooooooowly and the bubbles will be released to rise up inside the reservoir. You should feel an immediate improvement in the pedal firmness, though for maximum satisfaction you can do this with the cap off the tank and have someone watch for the bubbles.

You can try this trick at any time, e.g. when stuck in traffic on a steep down hill, and it's surprising how much it can improve things.

Having the handbrake on doesn't effect the process in anyway but it does stop the car rolling.

[AndyBrad]

Don't forget that the clutch shares the same fluid, so you should also flush the slave cylinder to.

Sent from my SM-G800F using Tapatalk

how do you do that?

[PaulAV]

When Nick did mine he used s pressurised bleed kit, used the nipple on the slave cylinder

[Liam22]

As I do this before every race meeting I have a couple tips:

1. Bleed with the engine running so that the ABS lines are open. Essential if you have any air in the system. Even if you don't, the flow rate is much increased and makes the whole job quicker.

2. Pump the brake pedal so that it is firm before and after bleeding each caliper. If you introduced any air then you immediately know which caliper to go back to.

[New Duke]

Thanks for the advice, guides and tips everyone. I've found a cheap vacuum gauge with container on Amazon so will do it that way:

Two more questions:
- Is bleeding the clutch at the same time an absolute must for it to function? Or just best practice to ensure there's no old fluid left? By that I mean: Can I bleed the brakes now and leave the clutch a few months until the next service is due? (Keeping in mind I have more track days booked this year, so the car will be worked hard)
- Do the same general principles apply when bleeding the slave cylinder as the calipers? E.g. can one person form vacuum on the slave nipple, pump the clutch pedal, then disengage the vacuum once the new fluid is pushed through? Or does it for any reason require 2 people?

Asking because I have to do this by myself without a helper, and if the clutch bleed is a two person job (?). Then there's no point even doing the brakes myself if I'm then stuffed by a slave cylinder if it must be bled at the same time... if you get me.

With or without this master cylinder nipple, you can improve the pedal feel after a change by pointing the car down a steep slope and holding the brake pedal down firmly for about 30 seconds with the engine running. This encourages any tiny bubbles in the fluid to coalesce and gather behind the master cylinder piston. Release the pedal slooooooooowly and the bubbles will be released to rise up inside the reservoir. You should feel an immediate improvement in the pedal firmness, though for maximum satisfaction you can do this with the cap off the tank and have someone watch for the bubbles.

You can try this trick at any time, e.g. when stuck in traffic on a steep down hill, and it's surprising how much it can improve things.

Having the handbrake on doesn't effect the process in anyway but it does stop the car rolling.

Gonna give that a go right away before bleeding as well, just in case it helps. Just got to find a hill in flat North Essex. Thanks

[SeriousSam]

The problem with using vacuum bleeders at the nipple end is that when the nipple is closed you can pull a vacuum just fine, but when you open it, air can get in round the threads. This slows down the rate that fluid is drawn through, leaks the vacuum, but also introduces lots of air bubbles into your tube making it harder to recognise real air bubbles being expelled from the system. They do work, but the more reliable method in my experience has always involved 2 people.

[qwakers]

ptfe tape round the nipple threads helps with that problem

[SeriousSam]

Does need regular renewal though, at least that's what I've found. I used it for a time on my car and after about a year it had disintegrated. Don't get me wrong, being able to do it on your own is handy for sure, but having tried all the methods I personally always fall back on the assisted one.

[New Duke]

Thanks Sam, I'll try to wait until a friend can help me with it then. I volunteer to take photos and do a DIY guide with you at some point if you need someone, as this is more fiddly than I'd expected, especially for a service item.

Just opened up the brake reservoir and the fluid is dark brown with lumpy bits floating on top. Don't want to risk those running down and blocking the bleeder holes so I'll suck up what I can from the top first. May ask 13Black to replace the tank at the next service as it's quite gunky. Wish I'd got the brake fluid done last time I was up there.

Next noob question: Does anyone have or be able to snap a photo of the clutch bleed location? Looking online everything I've found refers to the oil filter as a reference point, but that's a different location on the S2. I've had a nose around but can't seem to spot it.

[New Duke]

lie on your back under the car with your feet towards the back of the car, the starter motor is above your right shoulder and the slave is above that. it looks a bit of a pig to get to tbh.

[New Duke]

lie on your back under the car with your feet towards the back of the car, the starter motor is above your right shoulder and the slave is above that. it looks a bit of a pig to get to tbh.

Perfect. Just what I needed thanks. In that case I'll bleed the brakes asap (as it's a bit of an emergency) and save the clutch for someone qualified/less likely to pour brake fluid in their eyes. Will just have to have some old fluid mixed in with the new for a while.

[TerryH]

If your doing this by yourself "billy no mates " or just don't want the hassle of trusting someone to depress and release the peddle at the right time

Then this works really well:

Gunson G4062 Eezibleed Kit

Had to use a bit of PTFE tape to get it to seal on the resivour as standard caps not quite right, or get one of these as well:

Gunson 77042 Multi-purpose Cap For Eezibleed

Once set up, went like a dream.

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