Saturday, August 21, 2010

Motul RBF600 Factory Line Brake Fluid

The brake fluid in the Slowtra is as old as the car itself so I guess it's time for a change after 4 years. Having used the excellent Motul 5.1 brake fluid previously on the SP I've decided to go for the same brand again. But this time round I'm trying the RBF600 having heard numerous praises and accolades mentioned on this brake fluid over the years. Unlike the 5.1 which is more for daily driven ABS cars the RBF (short for Racing Brake Fluid) 600 is a 100% synthetic Dot 4 race/performance brake fluid for race conditions but has proven to be long lasting as well.

So what's the deal with all the DOTs? DOT or "US Department Of Transportation" is used to classify the various fluids in the market. DOT 3, 4 and 5.1 brake fluids are glycol based while DOT 5 is silicone based. The higher the DOT number the higher the boiling point of the brake fluid indicating the ability of the brake fluid to withstand higher temperatures. However please do not use silicone (Dot 5) based brake fluids unless mentioned ok to use in your car's user/owner manual as these can damage the ABS system and even the brake seals in your car. Interestingly enough the boiling point of the RBF600 exceeds the Motul 5.1 despite the lower DOT rating. Confusing huh? The wet boiling point of the RBF600 is listed as 216 degrees C/420 degrees F while the dry boiling point 180 degrees C/356 degrees F.

Motul sells the RBF600 in 500ml bottles so I promptly bought 3 bottles to be on the safe side even though most brake fluid drain/refill operations will use bout 2 bottles. Apart from brakes, brake fluid is also a very good hydraulic fluid and can be used for the clutch system which is where I'm intending to use my excess fluid. Beauty shot of the brake fluid below

The brake fluid is waiting to go in together with a whole host of other stuff when I can find some time.


Mugil said...

i think there is rbf660 too if you want to go higher!

maybe more suitable when you get a set of 6 pot wilwood on the front!

Andrew Saw said...


You're really poisonous :) Am really thinking of Wilwoods. BTW any plans to upgrade your Dynapros and disc rotor?

Mugil said...

well, i am quite happy with the brakes, but may go with a 2pc rotor to save weight and perhaps a little more braking torque. I got meself a Polymatrix B compound now, and will be ordering the caliper repair kit. Will do a complete service of the caliper and seals before i put in the b compound pads. Brakes are OK, but after experiencing fade a couple of times in SIC...I think its probably killed the current pads and also the heat cycle they go through, needs more care hence the service kit.

Andrew Saw said...

My turn to do some poisoning :) Considering your whp you should try Wilwood 6 pot caliper with differential bore and 300mm 2 piece rotors. I believe Wilwood supply 6 pot calipers with 3 square inch total piston surface area which should be ok with the upgraded 1" master cylinder.