Boiled brake fluid - what now?

Had a great day at Donnington yesterday. However, at the end of a hard session towards the end of the afternoon the brakes went VERY soft.

Thankfully there was a Lotus engineer there and he said all would be okay once it cooled down, and it was. All down to a hot day and hard driving (there was a nancy in a new blue GT3 who really wasn’t trying, David I thought they were meant to be fast! ).

Now how do I fix it? The Pagids look like there’s plenty left but the front disks measure a little thin (apparently they’re skimmed Citreon disks and are near the minimum went fitted!). What will help the most:

  • New top notch oil
  • Braid lines
  • Geary’s Alu-belled disks
  • The Edwards/Admin5 DIY brake ducting
  • All of the above (in which order?)

Cheers, Ian

Ian

For starters, just get the braided hoses & use Castrol SRF fluid - in fact, I’m surprised that you’ve not got these already. You will only need to upgrade to the Geary ali belled disks when the existing ones are shot!

You may then, or may not need to duct air to the front brakes. I’m going to have mine done soon - at a very, very warm Oulton on Tuesday, my brakes were not as I would have liked - in fact on a couple of occasions I nearly failed to slow enough to enter the Knickerbrook chicane. Fortunately, there is an “escape” facility at Knickerbrook, whereby you can drive straight on’ if necessary. I have utilised this in the past - but only whilst the heavens were open & the rain was pouring down.

You’ll be amazed at the difference the braided hoses/fluid will make - they’re really a must for trackdays.

Cheers Pesky, yeah I know I should have done the hoses by now.

But will it help the over heating? Or will I just end up cooking the oil more? (which is why I should use better oil… to partly answer my own question )

Ian

Ian

It’s pointless not upgrading the fluid when fitting the braided hoses - system will need to be bled anyway!

Racing fluid eg SRF has a much higher boiling point than the normal stuff. However, it should be changed every year (assuming no more than 10 or so trackdays), as it is hydroscopic & “goes off”. IIRC, it says on the SRF tin that it should be changed every 18 months or sooner - but why take a chance for a few quid? I would be surprised if racers, such as SimonS & MarkD, don’t change their fluid pretty regularly.

The braided hoses should of course eliminate the spongy pedal.

IIRC the hoses cost about �70 & the SRF about �43. I would also budget for 2 to 3 hours for the work to be done - assuming you’re not a dab hand at that kind of stuff yourself!

Ian

I can only 100% agree with Pesky about Braided hoses and SRF.

However I really recommend you consider changing the fluid at least every half year and when the Pagids are half worn they are almost shot IMO …

I found this out an Aintree braking on the back straight from 125 down to 50 or so and I really thought my brakes were gone ( and I have braided hoses and Geary disks etc ) - turns out my SRF was shot and the RS14 were just starting to show the rivits. New fluid and new pads - great pedal again.

If you do the hoses yourself the front ones are a pain and the system really needs pressure bleeding for best ( quick ) results.

Cheers

ps - If you want to see really crap fluid - bleed the clutch first

Agree with Pesky too.

Castrol SRF is “the tits”

Shop around for SRF coz i can get it for �27

Thanks chaps!