Brake fluid change intervals - myth?

I used to run a Mk5 RS2000 and that'd boil the brake fluid after a trackday. Then again, it'd virtually set fire to the front pads on a fast B road run across Wales. I used to have to change the fluid every six months or so or suffer from pretty terminal brake fade on a fast run.

After a trackday it'd need new front pads and a thorough flush of the brake fluid. The drive home was always a bit hairy.

Weighed a lot more than an Elise though, and didn't have the Elise's trick heat dispersing discs.

Apart from hoses with much stiffer sidewalls it's identical.

I've used the car on track with normal road pads fitted, they are fine and don't fade but are not to my taste, not enough bite (unassisted brakes), and last for a very short time.

Neither of these changes keeps moisture out of the system, or stops the brake calipers reaching 300+C for prolonged periods of time, which is my original point, and that of this thread . . .

Fd

The 'trick' alloy disks don't last on track, almost everybody uses steel vented disks . . . those that don't ultimately end up with a catastrophic disk failure . . . the hub of the disk parts company from the braking surface . . .

Fd

The message from Fergus Duncan contains these words:

I've always assumed brake fade's mostly caused by the pads' coefficient of wotnot changing when they're stonking hot.

the heat has to go somewhere so if it's not getting into the calipers and the fluid then you must have very impressive cooling on your brakes :) why else do some calipers have water cooling? why else do truck have water spry on their brakes when they get too hot?

I subscribe to a US based BMW mail group, and that's the recommendation there. Of course, near all our US cousins have strange ideas about the life of car fluids of all descriptions. Perhaps because they used to be so cheap. Still are, compared to here. But not for that much longer, I'd say.

I've had cars which probably haven't had a fluid change in, what, 7 years or so. When I do get around to changing it the colours is always dark brown with lots of particulates in it. Where does this crap come from? I always assumed it to be the rubber hoses as the liquid in the pipes is practically static and doesn't get cycled with the master cylinder. I myself am non convinced it is absolutely necessary to change fluid every couple of years. I am sure it's just a safety net for manufactures. I would get 90% of cars over 2 years old on the road have fluid over 2years old! Anyone else care to put a % on it?

Keep well,

Will

all you can do is do the best you can for your car at least when the guy in front is sitting too close you won't hit him up the arse with your motor and it's sorted brakes will you :)

Well, you learn something new every day!

The message from " dojj" contains these words:

It could just be a very good insulator. ;-0

As for trucks spraying water - I thought that is dribbled into the middle of the ventilated discs so it cools 'em from the inside without getting the braking surfaces wet. At least - that's how I'd do it though I've never looked into it.

The message from DuncanWood contains these words:

I've only twice got a car so badly het up and neither time was I really concentrating.

Guy King ( snipped-for-privacy@zetnet.co.uk) gurgled happily, sounding much like they were saying :

I've had brake fluid boil to the stage of no brakes in heavy motorway traffic... Stopping and cracking a bleed nipple (the joys of inboard front brakes) released steam. To be fair, it was on the 4x4 which had been woefully neglected since last being submerged...

The message from Adrian contains these words:

I hardly use my brakes on motorways, heavy traffic or not! Actually I hardly use my brakes at all.

Guy King ( snipped-for-privacy@zetnet.co.uk) gurgled happily, sounding much like they were saying :

Nor, normally, do I - it's a failure of anticipation and observation.

This was by the M25/M40 jn, on a hot summer friday afternoon, in stop-

The message from Adrian contains these words:

Ah - I used to do that run most weeks. In the end I a) decided to just let 'em and b) moved to Telford where we don't have traffic.

I doubt that.