I was at Snetterton yesterday and boiled my brake fluid on my last session of the day. I am running the 308mm front discs and RS14 pads rears are standard. I am not sure what caused the fluid to boil but it was quite scary at 135mph on the back straight and went to press the brake pedal and got nothing, one pump and there was just enough to stop and get around the corner without using the escape road. Drove round another full lap and then the car park for a while.
I am now wondering what to do other than change the fluid for 5.1 (never did it when we did the front brakes, the mechanic was sure he had 5.1 when we did it it wasn’t and the car was already in bits)
I am thinking about RS42 rear pads as the don’t need the extra temprature of the fronts with the 290mm AP ally belled rears? What do you guys think?
Hi Ade
I run the 308mm discs & RS14 up front and the 290mm & RS14 on the rear & Castrol SRF fluid and braided hoses.
I had a similar experience at the end of Hangar straight a couple of weeks ago after a 40min extended session.
130mph and reduced breaking = gravel,grass,gravel,tarmac
Just put it down to staying out too long.
What else is there to do ?
Glad it is not just me, I had done about 10 or so flying laps (after a couple warming everything up) so I was out for at least 25 minutes, it was to be my last lap anyway.
Which AP rears do you have? drilled or groved?
Not sure we can really do much more other than run ducting to the discs? but I suspect that might be hard due to the oil coolers etc getting in the way!
Ducting helps a lot but only if you apply it correctly
‘Upgrading’ fluid to 5.1 will only help if you get decent stuff. Some of the cheap 5.1 fluids have a lower boiling point than the lower quality DOT 4 stuff, which I don’t really understand. Better go for something good, branded or even as far as SRF, even though its pricey. Ducting will also help if done correctly.
Interesting you got boiling, prob because the fluid was old?!
Jonny
The brake fluid was not that old, but suspect it was a bit of a mixture with some old in the rears after the front caliper change. I am going to get it changed for a good quality Dot 5.1 and maybe change the rear discs to.
Useful…
Good read, not sure the bank manager will run to SRF but the Motul RBF600 looks a good price\performance option.
I asked the question of SRF recently and the consensus it wasn’t needed. I did it anyway as there is no point scrimping on safety.
I am running std. cals, discs and lines with Performance Friction PF01 pads and SRF fluid.
I have run 30 min sessions and not had a single hint of fade.
BTW I can supply PF01’s at about �20 cheaper than the equivalent Pagids.
Can supply Pagids if you want them too.
Seems a bit odd that you had a problem at the end of the staight? Surely the brakes should have had a rest by then, and the problem would have been more likely after a series of stops? Wondering if the brakes had started binding in some way and hence heating while heading down the straight?
I ran with std disks calipers and RS14s (although with SRF) until recently and haven’t had any problems, even at Donnington, which I’d say was significantly harder on the brakes than Snetterton.
Oh and if I have just broken forum rules on commercial stuff let me know
Oh and if I have just broken forum rules on commercial stuff let me know
Nah, mate, if you can do some good deals for fellow Exigers, everyone’s a winner
Hang on I’m getting lost…(sorry for butting in ade)…I’m just changing the brakes(and dampers), have the front clam off! So fitting AP 4-pot (Hanger111), RS14’s, braided hose’s (eliseparts) and what fluid, DOT 5? And should I change the rear pads from standard (fairly newish I might add)to Pagids? Is there anything else I should do to the rears?.. Or while the front clam is off for that matter?
IMO you will be fine on std. rears as they make less of a contribution…we recommend on PF01’s up front and 97’s on the rears.
As your going to all that expense on the other items I would recommend Castrol SRF. It took 3 ltrs to flush and fill my Exige.
When I fitted EP alli belled disks with Pagid RS42 pads, i changed the brake fluid with Hulfuds DOT 5.1.
I had NO issues with anything even at Donny, and the brakes got so hot the disks were turning blue! But no fade at all with a rock hard pedal too!
Quite impressed really!
Hand what fluid, DOT 5?
Do not under any circumstances use Dot 5 brake fluid - it is silicon based and will cause a world of problems.
Use a good dot 4 or dot 5.1.
Hand what fluid, DOT 5?
Do not under any circumstances use Dot 5 brake fluid - it is silicon based and will cause a world of problems.
Use a good dot 4 or dot 5.1.
Noted, thanks!
In my last exige I also boiled the fluid, as it was just before I was going on holiday my only choice was halfrauds, I got there ‘high’ ( or somthing like that) quality dot 4 and never had any more problems.
Gav
In my opinion Pagids are poo once you start pressing on. I use Performance Friction 01 compound front and rear on AP 295 disks with SRF in my race car and have never ever had any fade issues at all. I tried various Pagid compounds before going to PF pads and none of them were a patch on the Performance Friction pads.
I have also read on hear that paople think you have to change SRF every couple of months. That is also not true. I bleed my brakes and change the fluid at the start of each year and that is it. They never fade and the last lap of the last year is as good as the first.
A set of front pads and disks will last about 18 months, the rears about 24 months.
Just my 2p’s worth.