Benji554

iTrader: (18)

Hi,
I have recently acquired a 330S with a k sport 8 pot upgrade on the front. I need to change the fluid soon and I have no idea what I should be using. Dot 4, dot 5.1??? Car is for fast road/occasional track day use (Pagid Rs29 pads front & Ferodo DS2500 rear). Many thanks for any advice.

quattroowner

iTrader: (5)

Be a safe bet with AP Racing 5.1 Brake fluid. More than adequte for your needs, Just make sure it's fully bled. Only downside of DOT 5.1 is it's more prone to moisture ingress. So change every year is possible

Benji554

iTrader: (18)

Cheers Quattro. So the advantage of dot 4 is less moisture ingress but lower boiling point??

quattroowner

iTrader: (5)

Im pretty sure that's it fella. Also dot 5.1 gives a better "feel" but im not sure thats 100% or old wives tale.

AS Performance

iTrader: (4)

quattroowner you have it mixed up..............the Dot regs are a basic guide for min. stds of b/fluid BUT dont directly relate to performance

dot5.1 is a specific ABS reg and part of its make-up is to resist moisture!!

because of its exact spec the likes of Motul dot5.1 makes a very good "fast road" type fluid
if you want something more suited to track type driving then the Motul RBF600 is cost effective and a good performer

if you want the "best" then the PFC RH665 b/fluid will outperform anything you have previously used

AS Performance

iTrader: (4)

as an aside do NOT get mixed up and confused with dot5 which is silicone based and must never be used on a performance car IMO..............

Benji554

iTrader: (18)

Thanks very much for the info guys

MixMan X

iTrader: (7)

Do you know how much fluid is needed for a change?

fpan

iTrader: (11)

I also thought that a DOT5.1 fluid is more hygroscopic than a DOT4 equivalent, the advantage of the DOT5.1 is its higher boiling point.

Hence why a DOT5.1 fluid needs to be changed more regularly as suggested.

RICHARD J

iTrader: (4)

Performance Friction is about the best available and still a DOT4

Bob99

PFC RH665 Dot 4 fluid has a higher boiling point than 5.1, it really is the best I have used.

stonejedi

iTrader: (51)

+1 THIS!!! the best out thereand i have tried quite a few,you really notice the difference on the peddle after a good braking session.SJ.

Benji554

iTrader: (18)

Yeah I like to know this too?

stonejedi

iTrader: (51)

It can be done with 1 litre but i would get 2 just to be on the safe side.SJ.

Benji554

iTrader: (18)

Great, thanks.