93 replies to this topic

[Scuffers]

OK, so what I am reading from this is that cars with questionable brake fluid/pads have experienced it?

 

let's try it another way, who has had it happen to them with decent, current brake fluid/pads?

 

(it's worth mentioning that different pads have very different conduction characteristics, also when they start to run thin, this will get much worse.) 

[techieboy]

I'd only had the car two days, assumed a recent service (and full Poxhall service history) actually meant something and knew no better at the time. For sure, since I took the car on and started spending on quality gear, it's never happened since. 

[Zoobeef]

Probably worth saying. With halfords racing fluid. (Boiling points very good for the price!) CL RC6 pads and standard discs I've had not a single bit of fade or anything. That's being out on track for over 45 mins too. Granted I don't have much power but I see the next steps as discs and cooling and then that should cover me for power increases.

[chris_uk]

as far as im aware the best fluid you can buy is the Gulf RF1000 DOT4 fluid.. (boiling point 325c) which is a decent price.. 

[Scuffers]

actually the bigger problem is age...

 

whilst some fluid has really good dry boil point, it's wet point is hopeless so unless your into flushing the fluid every 5 minutes, it's useless...

 

 

for example,

 

Comma 5.1 - Dry 260c, Wet 180c  (min spec for Dot 4/5.1)

AP Racing Super 600 Brake Fluid - Dry 315c, Wet 204c

Castrol SRF - dry 320c, wet 270c

[color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;]Gulf RF1000 DOT4 - Dry 325c, Wet 205c[/color]

 

 

So, as you can see, whilst they are all good dry, the wet points vary a lot...

Edited by Scuffers, 09 May 2014 - 06:18 PM.

[Zoobeef]

Halfords racing Dot 4 dry 308°c, wet 204°c, £7.68 for 500ml  So for the price it's not far off others. That castrol smashes all the wets out the park though!

[Steve.i.am]

Forgive my ignorance, and I should probably look it up & educate myself, but what does 'wet' mean? I am aware hydraulic fluid absorbs moisture over time (the reason I kinda attributed to my fluid boiling at blyton that time). But is that what wet means? Ie, it has absorbed a certain % by vol of water over time? Or something else? Since my episode at blyton I change my fluid at least every spring.

[Scuffers]

read this:

 

http://www.opieoils....d-Explained.pdf

[JG]

I try and avoid anything written by Opie. 

[haggi961]

If you want to know anything about oils and brake fluid isn't fezzasus the best person to talk to as he works with it?

[chris_uk]

The DOT specifies two reference tests for brake fluids.

 

* Dry boiling point - the boiling point of fresh fluid

 

* Wet boiling point –the boiling point once the fluid has absorbed moisture

(representing brake fluid after time spent in a real situation).

[smiley]

let's try it another way, who has had it happen to them with decent, current brake fluid/pads?

 

RS14 with one year old dot4

But like i said, i'm a bad example and do not brake correctly as every instructor tried to explain to me.

(i just cannot get it into my mindset, and hope the RC6 are so agressive they come close to normal braking effort)

[Tommess]

 

@Scuffers

 

You have tested this pistons?

So how you can decide that they are wrong?

 

Sorry?

 

Never said they were wrong, just not convinced they are needed?

 

I have used stainless pistons, and they are ok, but not a fit and forget item, they did need to be serviced/cleaned a lot more offten.

 

Why do they have to be serviced a lot more often? I don't get the point here, can you explain a little more?

[Scuffers]

Why do they have to be serviced a lot more often? I don't get the point here, can you explain a little more?

 

 

don't know 100% the reasons, but Stainless in an  ali housing = corrosion 

 

so what happens is the pistons usually get a layer of crap on them outside of the seal, this then gets dragged into the seals and causes air to get in, how long this takes depends on a lot of things, but for track cars it's not that long before you have to pull them apart and clean them up (I was finding I was having to do it every 8-10 hours of track use (approx 2-3 times the pad life).

 

not saying this happens on every one, but certainly did on the ones I have used, from what I am told, if the calipers had a second seal (like dust boot) then this would reduce the issues if you back-filled the boot with brake grease.

 

way I see it, if you going to change from Ali, might just as well use titanium, solves the heat problem better and has no issues with corrosion.

Edited by Scuffers, 14 May 2014 - 12:54 PM.