scoobyc

iTrader: (2)

Hi,

I have specced up some new brakes as they seemed to go a bit spongy at brands, and was after some advice on which brake fluid to go for.

Brakes are gonna be my98sti - grooved std size disks with ds2500 and uprated hoses..

Car is going to be used for the occasional track day, and still needs to be drivable on the road.

Seems other threads say to use RBF600.

Do these higher boiling point fluid have any detremental effect when cold?

Seems ill be needing about 1.5l of the stuff.

Any Recommendations?

Scoobyparts Ltd MILLERS RACING BRAKE FLUID 300 PLUS

??

Chelspeed

Go to Halfords and buy any Dot 5.1 fluid. It will be fine.

All of these super duper top of the range race fluids are for which have brakes which for some reason end up with massively high pad and caliper temperatures. One example was our historic mini rally car which for homologation reasons was restricted to tiny non vented discs in 10" wheels despite having 140bhp. We saw temps so hot that the seals in the calipers melted and the grease ran out of the wheel bearings like engine oil. Castrol SRF meant that despite this the fluid was OK.

There's no reason for any impreza with reasonable size vented disc brakes to reach anything like this temp even on the track so no need to go wild on fluid.

But if you do for whatever reason then when it's cold it will behave perfectly normally. The only downside is that most race fluids will absorb a lot more water vapour from the air than normal fluids so they need changing more regularly to keep their high temperature capability.

scoobyc

iTrader: (2)

ahh ok good advice.

Im curious as to why dot 4 is recommended over 5.1? 5.1 more damaging to rubbers?

I guess the temp difference between the fluids is only 20deg c or so?

scoobyc

iTrader: (2)

Is it just heat boiling point which makes the difference or is there other factors?

cusco kid

hi again m8 if you want tecnical info go to COMPBRAKE.CO.uk site
click on tecnical support then BRAKEFLUID this site will tell you why not to use dot5 fluids
we use ATE SUPER BLUE in both track cars .dot 5 should not be used in competition cars /track cars the reason will be explained here on compbrake site geo

scoobyc

iTrader: (2)

coolio. will give it a readio.

scoobyc

iTrader: (2)

Ok so i need to be going for a high boiling point dot4 solution as to stop water beading in the caliper.

Any particular recommendation?

Currently the plan for the car is not hardcore track use. More fast road with a track day once a month and a couple of trips to the ring i guess. No all day races. Probably max 20-30 min sessions a pop.

Chelspeed

Agreed not to use dot 5 but note I recommended dot 5.1. There is a difference and it's an important difference.

The reason that some people suggest dot 4 is that the dot specs are for road fluids and the more top of the range race brake fluids, while better at working at the extreme temps, also absorb a lot of water from the air as I said before. This means they can't meet the longevity bits of the dot 5.1 tests so end up being classified as dot 4.

That doesn't mean dot 4 is better than dot 5.1 it's actually overall worse for a road car as you have to change it more often. But for a race car the extreme temp resistance means you won't mind this so, despite a lower dot rating it's better. Confusing or what?

So my advice hasn't changed. For a road car and some track use dot 5.1. For a monster full race car then a specialised race fluid (which will probably end up being dot 4) and will need changing more often than once every two or three years.

172sport

iTrader: (6)

No issues with DOT4 for me, and i'm really hard on brakes.

Thats on track too.

cusco kid

go and use A.T.E super blue you wont go wrong with this fiuid then you wont be confused by all the jargon cheers geo
the guys at COMPBRAKE dont get it wrong

Chelspeed

> you want tecnical info go to COMPBRAKE.CO.uk site

What a confusing and misleading site! They talk about dot 5 in depth (silicon fluid) but only give a passing mention of dot 5.1?

All the temperatures are confused between degF and degC. Looks like they've just cut and pasted from a US website without bothering to understand the difference.

Quote "ATE Super Blue - Dry boiling point is 536 degrees (122 degrees F)". Huh? How can 536 deg be 122 degrees F? 122 degrees F is 50 degC, if this is right your brakes wouldn't work on a warm smmers day from cold! I think they mean 536 degrees F (which is actually 280 degC) which is pretty impressive.

Quote 2 from Technical Tip on brake fluid - "typically 2 litres (2 pints)". Err no, 2 litres is more like 3.5 pints.....

I also looked at Technical Tip 6 on balance bars. That looks familiar I thought. The robbing ******* have cut and paste it from BG Developments - Technical Tips - Balance Bar Set-up without any acknowledgement.

I think if you want to know about brakes I'd stick to people who know what they're talking about.

Chelspeed

> Any particular recommendation?

Comp brakes ATE blue looks like it would be OK from the spec. AP Racing 551 would be fine and only £5/litre, that's what I use in my competition car. Castrol response. Millers racing brake fluid, not used it but I use their engine oil and I have a lot of time for the company.

scoobyc

iTrader: (2)

Cool. So whats the recommended change frequency with these fancy race oils then?

I was planning on servicing probably every 3 months/3track days. Probably change the brake fluid every double that.

ma_99

ive got motul 5.1 but next time im planning to use AP racing 5.1

scoobyc

iTrader: (2)

Roger Clark Motorsport - RCM Product Detail

This stuff?

AP Racing. Whats the deal with this fluid? Ok for road/track 4pot fronts with ds2500's,

What regularity of change will this require? Go 6months before next change?

If this is a recommended fluid i think ill buy.

Any other recommendations looking to buy today/tomorrow.

scoobyc

iTrader: (2)

MOTUL OIL - RBF600 HiSpec Brake Fluid :: £11.73 :: Accessories & Misc Parts :: Brake Fluid ::


RBF 600 seems good but its twice the price of the AP stuff

(taken from porker forum)
DRY:401F -- WET:284F --- DOT3 MINIMUM (GLYCOL BASE)
DRY:446F -- WET:311F --- DOT4 MINIMUM (GLYCOL BASE)
DRY:500F -- WET:356F --- DOT5 MINIMUM (SILICONE BASE)
DRY:500F -- WET:356F --- DOT5.1 MINIMUM (GLYCOL BASE)
DRY:527F -- WET:302F --- AP RACING 551 ($12.95/0.5L OR 16.9 OZ)
DRY:527F -- WET:347F --- VALVOLINE SYNPOWER DOT3 & DOT4
DRY:536F -- WET:392F --- ATE SUPERBLUE/TYP200 ($9.95/1L)
DRY:543F -- WET:349F --- Endless The truth DOT 4 ($35/1L)
DRY:550F -- WET:284F --- PERFORMANCE Friction Z rated ($6.27/16 OZ)
DRY:550F -- WET:284F --- FORD HEAVY DUTY DOT 3 ($4/12 OZ)
DRY:570F -- WET:284F --- WILWOOD 570 ($5.65/12 OZ)
DRY:572F -- WET:284F --- US Brake/AFCO Racing 570 Gold
DRY:572F -- WET:421F --- US Brake/AFCO Racing Ultra HTX
DRY:577F -- WET:300F --- Brake Man
DRY:585F -- WET:421F --- Earl's Hypertemp 421
DRY:590F -- WET:410F --- AP RACING Super 600 ($16.95/0.5L OR 16.9 OZ)
DRY:593F -- WET:420F --- MOTUL RBF600 ($12.95/0.5L OR 16.9 OZ)
DRY:590F -- WET:518F --- CASTROL SRF ($69.00/1L 0R 33.8 OZ)
DRY:601F -- WET:399F --- BREMBO LCF 600 PLUS ($26.75/


track day brake fluid - Pelican Parts Technical BBS

scoobyc

iTrader: (2)

Hm think im going to go for the RBF600.

Cheapest i can get is £13 /500ml inc delivery. Anyone know anywhere cheaper? Gonna need 4l of the stuff.

Also, By choosing the dot4 over a dot5.1 what will be the negative/positive impacts? The rbf600 has great reviews and good boiling points.

stockcar

4ltrs??? what on earth for??
you'll use 1ltr if your sorted in bleeding brakes or maybe 2x if your not very effecient

alyn

scoobyc

iTrader: (2)

more than one car.

oilman

iTrader: (9)

Plenty here, the racing DOT 4's like Motul RBF 600 have the best short term performance, there is always the Castrol SRF if you need what the F1 guys use, it's for life as it never boils and is not hydroscopic!

Brake fluids

SRF

Castrol SRF Racing Brake Fluid

Cheers
Guy

Evo Bizz

iTrader: (1)

Can you explain the 'it's for life' part when it says this on your site?

The use of Castrol SRF should be restricted to not more than eighteen months before draining and refilling for maximum efficiency.

oilman

iTrader: (9)

It was originally designed for Ford, who backed out at the last minute. Ford wanted a brakefluid that was fill for life and would never need changing, Castrol took on the task and came up with the SRF, Ford then backed out due to cost after Castrol had spent and awful lot having this stuff developed.

Castrol were left with a product and no one to sell it too, so it found its way into the motorsport world where it has pretty much stayed. Under extreme conditions it will get contaminated and need changing, for road use it wont... But of course Castrol are not going to say that are they or else people will fill up with it and not buy anymore again, they want you to keep buying it.

Cheers

Guy.

stockcar

really..................