Brake fluid

I have been recommended Castrol SRF (Dot 4) brake fluid. Does anyone know if this stuff is OK to use in the Elan’s brake system?

Of course I would flush through with the new stuff to ensure that as little as possible of the old fluid remains.

Dot 4 will be fine. It’s Dot 5 (synthetic) fluid that is incompatible with the others (confusingly, Dot 5.1 is mineral and is also okto mix with other Dot ratings).

  • I race with Castrol SRF ( DOT 4 ) . No problems at all.

Dag

I used SRF for a number of years in my Elan without problems. I changed to other competition brake fluids a while ago now as the SRF became to exspensive in Australia.

cheers
Rohan

It is not so cheap here either :open_mouth: However it has been recommended by a number of people I know and trust.

What is the difference between Castrol SRF and LMA?

Castrol LMA is less expensive and has a much lower boiling point. The SRF stuff is mainly used for racing where brake temps are much higher. I was finding that the brake pedal was going soft by the end of a track day session and the pad temps were with in their parameters, so higher temp fluid is the next step.

  • even if it’s expensive, do not “forget” to change it…It is hygroscopic, and having breaks is a good thing… :wink:

Dag

Steve,
Silicon Ester Racing Fluid (SRF) will be okay in an Elan and is probably one of the better fluids out there. Don?t confuse Silicon with the unsuitable silicone fluid and it is miscible with DOT 3 and 4 fluids. It also has a much higher boiling point than DOT 5 and is less hygroscopic compared standard fluids.
LMA is an old fluid developed by Castrol in the 1960s

Regards
Steve

In my experience brake fluid used to be hydroscopic.

If it now hygroscopic - is this due to the silicon content?

Brian Clarke
(1972 Sprint)

Hi Brian,
It’s always been hygroscopic regardless of content.

Cheers
Steve

Not knowing a lot about brake fluid, and to put my simple mind at rest, I checked some ‘facts’, and verified that:

DOT3 & DOT4 fluids absorb water (makes solution), and is therefore, hydroscopic.

DOT 5 & DOT 5.1 fluids adsorb water (attracts only), and is therefore, hygroscopic.

Knowing the difference between hydroscopic and hygroscopic became quite an important issue in my transmission days.

Brian Clarke
(1972 Sprint)

Hi Brian,
I do know a lot about brake fluid. Hygroscopic means the ability to attract water molecules, Hydroscopic ? not sure it?s a real word - may be in America
The DOT rating has nothing to do with hygroscopic its just a performance standards ie if a fluid meets a boiling point, low or high temperature viscosity etc In America it is FMVSS 116
At the end of the day we can call it what we like because absolutely everybody will understand what we both mean.
Cheers
Steve

Does anyone use AP 551 racing? its dot3 but has a higher dry boiling point than bog standard off the shelf dot4/5.1…

Doug

Hello all;

ATE SuperBlue far out performs Castrol LMA:

volvoclub.org.uk/faq/BrakeFl … rison.html

I race with Castrol SRF ( DOT 4 ) . its fine … but i also have brake cooling ducts to the front disks

As a bit of information I gathered recently, re brake and clutch fluids.
I had a near new Girling clutch cylinder fail with bits of black seals on the filler lid. Clutch travel went up and I ended up during a long race damaging the gearbox.
Anyway 2 specialists of the old school [ who I trust ] both asked what fluid was I using in the clutch system, to which I replied the cheapest Dot 4!
Advice is that some Dot 4 fluids have had lubricant removed to enable operating temperatures to be raised. Castrol Response Dot 4 was the fluid recommended - and it is only 10% more expensive than the cheap harmful stuff I used before!
Richard