Homer Posted June 7, 2005 Share Posted June 7, 2005 I've been 'promoting' CW pads/new discs/new fluid/new S/S brakes lines on the 'small' Jap brakes for some time now but think I've now realised they are not quite adequate for a BPU car... My current setup has been great for thrashing around twisty country roads and the usual A and B road stuff and has worked very well indeed. However this weekend had to brake hard from 170 leptons to 50 in a fairly short distance. At full speed I hit the brakes at about 60% pressure and the car slowed as I'd have expected, as the speeds got lower I had to apply serious pedal pressure to continue braking. Once I was down to 90 my foot was on the floor and the brakes were hardly working at all. Almost a brown pants moment! Is this brake fade? Fluid boiling? Too small discs/inadequate callipers? Quote Link to comment Share on other sites More sharing options...
terribleturner Posted June 7, 2005 Share Posted June 7, 2005 Darryl, sounds like a lucky escape. i think it's the fluid boiling (but i satnd to be corrected). I had a similar thing a month or 2 ago. You wanna see if you can jump on Nic's brake group buy. Quote Link to comment Share on other sites More sharing options...
Rob Posted June 7, 2005 Share Posted June 7, 2005 Brake fade would ease off if you release brake pressure for a brief moment. I'd be surprised if your fluid boiled up on one hard application of the brakes, unless it's very old. I would suggest it is good practice that you find the limit of your brakes in a non-emergency situation. Quote Link to comment Share on other sites More sharing options...
Jake Posted June 7, 2005 Share Posted June 7, 2005 Brake fluid can seriously underperform if it's been even minutely contaminated with moisture. The water in the fluid (obviously) boils at just 100°C, a temp easily achived by high-speed braking. Once the water has boiled and turned to gas you have a very spongy pedal. Homer, Do you know when the brake fluid was last changed? Quote Link to comment Share on other sites More sharing options...
Homer Posted June 7, 2005 Author Share Posted June 7, 2005 Thanks for the input guys. Jake, last time it was changed was around 6 months ago (3k miles). Until this weekend I've not pushed the brake system to the maximum, but it does get hammered a few times per week. Do you think its worth swapping for some new fluid? Quote Link to comment Share on other sites More sharing options...
Jake Posted June 7, 2005 Share Posted June 7, 2005 At that age/milage it should still be OK really. I'd start by fully bleeding the brakes and if that didn't help then completely changing the fluid for some fresh Motul 600 (from a brand new, sealed bottle) Brake fluid leeches mosture from the air, using fluid from a previously opened container is less than ideal. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 8, 2005 Share Posted June 8, 2005 If the pedal sinks lower it's fluid boil or a leak. pad fade is when the pedal stays high and hard, but the car just doesn't slow down. Quote Link to comment Share on other sites More sharing options...
Nic Posted June 8, 2005 Share Posted June 8, 2005 Darryl, sounds like a lucky escape. i think it's the fluid boiling (but i satnd to be corrected). I had a similar thing a month or 2 ago. You wanna see if you can jump on Nic's brake group buy. H you've still got a few more days if you want to be in on the group buy, I'm just collecting order forms and payment at the moment so let me know ASAP Quote Link to comment Share on other sites More sharing options...
Whitesupraboy2 Posted June 8, 2005 Share Posted June 8, 2005 If the pedal sinks lower it's fluid boil or a leak. pad fade is when the pedal stays high and hard, but the car just doesn't slow down. never knew that and thanks that very interesting, fluid change for me then as i had fade the otehr day. Its DOT 5.1 i wana use isnt it Quote Link to comment Share on other sites More sharing options...
Homer Posted June 8, 2005 Author Share Posted June 8, 2005 If the pedal sinks lower it's fluid boil or a leak. pad fade is when the pedal stays high and hard, but the car just doesn't slow down. Thanks Chris, sounds more like pad fade in that case as the pedal didn't actually sink, just the braking power seemed to go away. Edited to add that I had motul 600 put in when the fluid was changed, plus new stock discs and braided brake lines. In your opinion would your race pads make any significant difference over the fast road ones or should I look towards the 'UK' setup? Quote Link to comment Share on other sites More sharing options...
Homer Posted June 8, 2005 Author Share Posted June 8, 2005 H you've still got a few more days if you want to be in on the group buy, I'm just collecting order forms and payment at the moment so let me know ASAP Cheers Nic, if I had the money I would, believe me! Might have to wait a little while until my bank balance is back in the black!! Quote Link to comment Share on other sites More sharing options...
chris aka fonz Posted June 8, 2005 Share Posted June 8, 2005 I think i found the limit of the j spec brakes last wk end at a track day at Donnington ! So definatly got too upgrade them soon. Quote Link to comment Share on other sites More sharing options...
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