Hi all.
Just had a spirited track session and i think i boiled the brakefluid. I can depress the brake till it hits the bottom. When i pump it -it comes back up a bit. As if there is a airbubble in the system. Has anyone else had this problem?
Yes - there are many threads on this issue.
The quick fix is to replace the brake fluid with a higher temp brand. I use Motul 600.
The next quick and cheap item is to relace the stock brake ducts with GT3 ducts - they cost $30 and simply clip in.
These two mods worked fine for me, running 30 minute sessions at Sebring in summer.
Sounds to me like you nailed the diagnosis, and the word 'failure' sounds a bit extreme (assuming you didn't lose all braking). I would give it a thorough bleed if not a flush.
Flush the system and put in the Motul.
Did this problem happen during driving or after first time out after sitting pit side?
Certainly sounds like boiled fluid.
The question really is when was your brake fluid last changed? The key is to change it every 6 months or less and that will solve your problems for most situations, and only if you're spending extended driving periods on the track do you need to go to a different fluid.
For me in a 30 minute session with standard fluid I have no issues, and that's high speed (130 mph) with hard braking , but I do run with the PSM off most of the time to help ease up on the brakes.
thanx guys for the input.
4by4, yes, it happend pitside after 30min session.
will tell porsche centre to put in higher temp fluid.
You might not get your dealer to put anything but the standard fluid in. But as I said for a 30 minute session the standard fluid should be fine as long as it is changed frequently....but the same applies for high temp fluid as well, because it is water in the fluid that normally causes the issue.
Do you have a part number? Are you sure they fit?
The thickness of the pads can also come into play from heat transfer to the fluid. As others have said flush with Motul and if you're running an R comp tire switch to a race pad like PFC 01s.
mikeventer, when did you last replace your fluid though?
In all of this that is the single most important thing and may avoid all of your problems, as brake fluid is hydroscopic and so absorbs water (moisture in the air) and over time becomes saturated, and is worse in humid climates. With water in the fluid the boiling point is lowered significantly.
Once you've replaced the fluid follow what 4by4 says as a cool down on the last laps and if you are confident to drive with PSM off then do it, as that dramatically reduces brake heat.
When I come to rest in the pits I don't apply the handbrake to make sure there is no heat soak (although if present would be minimal) from the discs to the pads/pistons/fluid.
