Boiling brake fluid

[.Joe]

Hi there, i've recently started noticing that on track days i have to bleed my brakes mid day and at the end as well, seems like somethings making the pedal go soft quite often

my current setup
ate super blue
ferodo ds2500
grooved discs
goodridge braided lines on the front

could the need to change the rear be causing this?
when i come in after a session the wheels are boiling to touch

does anyone have a suggestion as to what i could do to stop this/make the braking a bit better.

many thanks

joe

 

[mark123]

Normal for the wheels to be hot when you come in.
Have you changed the fluid recently?
You could have slightly sticky caliper pistons, meaning the pads still touch the disc enough to generate heat even when your foot i not on the pedal.
Could also be braking too much into the corners - if you carry more speed through the corners you won't put as much heat into the brakes.
I doubt it is anything to do with the rears.

I'd check the brakes/bearings are all good and free and if all that checked out check your technique.

 

[Johnpacey1]

Take the front splash guards out and foglights. More cool air may help.

 

[MarkX]

More cooling and better fluid, I don't rate ATE at all, Castrol SRF in mine

 

[George@RTR_Parts]

Getting airflow through to the front brakes will help (if you haven't removed the front fog lights/arch liners already)

You may have some air in the system as you shouldn't really have to be bleeding them in the day. A full flush for fresh fluid should sort it , also as @mark123 has mentioned worth checking everything is working as it should ie no sticky calipers while at it

 

[.Joe]

I have cup racer brake ducts fitted currently just missing the deflector plates, I had dot 5.1 in before but that did the same, I'll definitely be doing another flush through before I go out again

 

[car.crash]

Are you doing any cool down laps before returning to the pits?

 

[MicKPM]

Sounds like you're going beyond the limits of the pads also. I really do not rate the DS2500 for track use at all and to me, the standard Brembo pad is actually just as good except it costs a third of the price.

You have brake ducts (nice) but no diverter plates (not great) but what wheels are you running as 2118's for example do not 'pull' air thru (which is why the X65 Cup race cars ran ducts with diverters). Do you have a direct and unobstructed air flow (no horn, bi-mode Inlet valve and charcoal canister removed)? Driving style also counts for a lot to and maybe you're exceeding your setup by slamming on last minute, hard, every time? If this is the case you may feel like a driving hero but you need to show some restraint and mechanical sympathy by changing your driving style. Finally, as already mentioned above, do you put in a good few cool down laps? These are seriously off-pace laps where you barely touch the brakes or go high in the revs... The idea being that you give the car a good 10mins to allow all temps to gradually fall before coming in.

I give Simon Bridgeford s**t all the time for not doing this with my old Clio at Bedford where my brakes went up in flame because he didn't cool down after a hero session.

 

[George@RTR_Parts]

It'll be the fluid boiling if pedal is going soft. See if you can get some reflectors on if you have them as they will help
But changing the fluid , doing proper cool down laps (as Mick says not many do this and just let off for last corner before leaving the track)

Then when you stop (leave in gear, not with handbrake on) , I always leave the bonnet up to let the car cool down ready for the next session. Simple but effective. If it's raining or you're going to watch other cars etc just leave on the first click of the bonnet catch.

These things will help massively getting rid of some of the heat

Also braking/driving style is a factor, but the above will help for sure

 

[warwickstingray]

Cool down laps are key. It's amazing how much the standard stuff will take if you take the time to warm them up and cool them down. If you really toast them and there is a really long pit then potter round for a bit when you come back in.
I also roll mine back a little a few times when I've parked up so the pads aren't Sat in one place on the disc while it all cools down.

Look after your car and you spend less time fixing it.

Unless you have a fat wallet and plenty of time and are in a position to not care!

 

[MicKPM]

By the way @G 172 those DS1.11's worked an absolute treat at Donington on Sunday. Absolutely zero fade, no fluid boiling and both discs & pads are still in remarkable shape (minor contamination but zero scoring). One guy remarked on how his bike didn't stop as well as my little Clio did from 110mph and I'm certain that the Cup, as it doesn't have ABS, wasn't really harnessing the full stopping power available as it would've just locked up (well, it did on one occasion).

Highly rated product and will defy be pushing these from now on over the DS3k for track use.

 

[George@RTR_Parts]

By the way @G 172 those DS1.11's worked an absolute treat at Donington on Sunday. Absolutely zero fade, no fluid boiling and both discs & pads are still in remarkable shape (minor contamination but zero scoring). One guy remarked on how his bike didn't stop as well as my little Clio did from 110mph and I'm certain that the Cup, as it doesn't have ABS, wasn't really harnessing the full stopping power available as it would've just locked up (well, it did on one occasion).

Highly rated product and will defy be pushing these from now on over the DS3k for track use.

Glad you're pleased with them Mick :up:

They really are fantastic pads mate and are getting more popular with lads who track and race their cars. Had nothing but praise for them

You sticking a thread up about your Cup when you get chance, was wondering if going the way of your black 172 or keeping this more standard-ish

 

[.Joe]

It'll be the fluid boiling if pedal is going soft. See if you can get some reflectors on if you have them as they will help
But changing the fluid , doing proper cool down laps (as Mick says not many do this and just let off for last corner before leaving the track)

Then when you stop (leave in gear, not with handbrake on) , I always leave the bonnet up to let the car cool down ready for the next session. Simple but effective. If it's raining or you're going to watch other cars etc just leave on the first click of the bonnet catch.

These things will help massively getting rid of some of the heat

Also braking/driving style is a factor, but the above will help for sure

i'll have to see if i can get some reflector plates from somewhere, the ds2500's were absolutely fantastic for my first couple of trackdays but since then i've picked up the pace somewhat.
i was thinking about either the ds3000 or the carbon lorraine rc6 and the brembo hc discs

Hi Mick, i try to keep the braking smooth, i've only the horns in the way but thes may be relocated somewhat as the mot is due soon.
i don't think the discs would be helping that much as they're drilled and grooved from a motor factors.

when i get a few days off ill be reflushing the system with the ATE super blue and possiblely new discs and pads to see what difference that makes.

 

[MicKPM]

You can make your own diverter plates from some aluminium sheet. Failing that, I think CMComposites makes them to.

Take the horn out, you don't need that on track

 

[.Joe]

You can make your own diverter plates from some aluminium sheet. Failing that, I think CMComposites makes them to.

Take the horn out, you don't need that on track

i've sent CMC over an email enquiring about the deflectors.
the horn is still in as its got mot in a couple of weeks but itll be getting relocated for ease later on

 

[George@RTR_Parts]

i'll have to see if i can get some reflector plates from somewhere, the ds2500's were absolutely fantastic for my first couple of trackdays but since then i've picked up the pace somewhat.
i was thinking about either the ds3000 or the carbon lorraine rc6 and the brembo hc discs
Hi Mick, i try to keep the braking smooth, i've only the horns in the way but thes may be relocated somewhat as the mot is due soon.
i don't think the discs would be helping that much as they're drilled and grooved from a motor factors.
when i get a few days off ill be reflushing the system with the ATE super blue and possiblely new discs and pads to see what difference that makes.

No worries, if you are doing more track days then the DS3000 or the DS1.11 are definitely worth considering. The latter are getting more popular and are fantastic pads

I've some "supergold" brake fluid in , same spec as superblue but the normal amber colour. Idea is to alternate between them so you know you have the all the old fluid out

 

[.Joe]

No worries, if you are doing more track days then the DS3000 or the DS1.11 are definitely worth considering. The latter are getting more popular and are fantastic pads

I've some "supergold" brake fluid in , same spec as superblue but the normal amber colour. Idea is to alternate between them so you know you have the all the old fluid out

What would the price on the DS1.11 pads be? i may replace the discs for some brembo ones whilst im at it

Cheers

Joe

 

[Tony Hunter]

Also add, that the position of the reservoir isn't in the best place in a Clio, right behind the manifold.
No deflectors on the race car, but would suspect it's a little lighter. Driving style has an awful lot to do with it as well.

 

[George@RTR_Parts]

What would the price on the DS1.11 pads be? i may replace the discs for some brembo ones whilst im at it

Cheers

Joe

No worries Joe, I've plenty discs in. I'll PM you now mate with prices ref the DS1.11


As Tony says driving/braking style does have a lot to do with it. I think he has moved the brake fluid reservoir on his race car. One of reasons I open the bonnet after a session to help get some of the heat out of the engine bay

 

[R14LYX]

Ate fluid is cheap s**t! I had it in my rally car and just bedding ds3000s in boiled the fluid! I quickly realised brakes are not worth skimping on and as much as we all hate it you get what you pay for!

 

[EVOgone]

Most Clios don't run enough rear bias (running std bias valve) and all the braking is on the front which carnt cope. But as said above cooling duct are a must.

 

[warwickstingray]

Didn't have the rusty rear discs issue on the 182 that I have with a cup. Unless you regularly do track days or drive around with the handbrake on they get pretty manky with only occasional use. By comparison my 206 diesel estate had red hot drums after a track day session.

 

[Munson]

An often misunderstood subject. No point using awesome pads if all it means is the fluid will boil before the pad material fades. I've experienced pad fade and fluid fade on track, and the latter is a lot more sudden and a LOT more scary.

Any braking setup has thermal limits. If you're still boiling new fluid, then brake less or increase cooling capacity. Obviously fit pads that are up to the job, but don't just stand on them constantly until the fluid boils. At least not if you're a fan of breathing lol.

 

[JD_RS172]

Only ever boiled fluid on a bike at mallory park. Fair to say my arse was spread on the inside of my leathers. Pad fade is a little more gradual.

Pad fade is an easier fix too. Once your fluids boiled you got to flush and change.