Thinking what to do about my on-going brake woes and the only untouched component is the rear calipers. I figure I may as well change them for completeness.
Before I give AndyD a nudge to get the spare set he has loitering in his garage does anybody have any or know how to get hold of a set?
You still having problems mate ?!
Yes Dave still not happy - they were better at Anglesey but still really long pedal travel 
Alcon rotors, refurbed front calipers, new master cylinder new braided lines, fresh 14’s, proper fluid the only thing left is the rear calipers. You’re not doing anything special with ducting are you? That’s the other thing to try as Andy reckons it makes a difference.
Car has not moved since Anglesey so don’t even know what the drivetrain issue is either,…oh and one of the SC to inlet manifold bolts has sheared. It needs some time at the Edwards Exige Care Facility.
On that note if anyone is driving past West London with an empty trailer heading up to the midlands then let me know…remote possibility I know.
Is it a standard new master cylinder ?
Nope, nothing special with mine at all - standard master cylinder, front/rear calipers and the large AP discs all round (305 front, 295 rear) RS14s and Wurth fluid. No ducting at all as yet.
Is pedal travel ok initially ? Is it only after a hard stint you get the long travel ? What fluid do you have in there ?
Could it simply be in need of a good bleed through?
Sorry I’m not more local - would have been happy to take a look with you - I’d guess the drivetrain issue might be a cooked CV boot ? - you should be able to see it if you check
[quote=Benja]Thinking what to do about my on-going brake woes and the only untouched component is the rear calipers. I figure I may as well change them for completeness.
Before I give AndyD a nudge to get the spare set he has loitering in his garage does anybody have any or know how to get hold of a set? [/quote]
That is no good at all Ben… 
Cannot see how changing the rears would make any diff? Is your master cylinder the same as Robs?
I am sure you checked the obvious to see if the pedal pumps up at all… so perhaps it is a linkage issue?
Hope you get it sorted soon. If you need you car delivering to London, I would be happy to drive it down for you 
Thanks for the concern and offers of help guys it is appreciated. To answer the questions that were raised…
After recent work pedal starts off as I would expect with reasonable travel and a good feel. After 15-20 mins of hard circuit work pedal has a long travel and although bite is still there its hard to modulate and impossible to heel/toe. It might be me but I swear the pedal actually goes to the floor when really really hot. It gets better when cool but never goes back to how it was before - like it needs bleeding again. All reasonable things have been tried by me and people I know and trust.
As for the setup :
Alcon Rotors 295F and 282R which are often regarded as superior to AP equivalents - 304F and 295R AP seems to be a common option with people that are happy. Trying that is a �1200 punt though
R600+ fluid as recommended by Randy. New Eliseparts Master Cylinder with a thorough bleed done by Martin when he fitted it and again by Randy when he changed lines, refurbed calipers etc (both in last 3 months).
So you can see that by a process of elimination the only thing untouched is rear calipers - I can’t see that it would make a difference either. I guess it comes down to try that or accept that rotors are a consumable as way of reconciling throwing another �1200 at it.
Agreed Dave the drivetrain sounds like cooked CV boot but inboard and outboard on both side are intact and there is no oil anywhere thus exhausting my mechnical investigative skills. As usual Martin/Steve will come to the rescue on all counts, I just need to get the car to them. All the pain will be worth it when I pick it up again and as such I’ll probably decline your kind offer Pete 
Insight/advice etc always welcome.
Certainly very strange - again I can’t imagine its the discs, as you said Alcons have a great rep and I can’t see discs causing that sort of issue anyway.
To me it does sound like either boiling fluid or a small amount of air in the system somewhere.
Puzzling when you’ve changed everything !!
Ben
You need the Lotus Motorsports Master Cylinder… both Martin & I tried the Eliseparts “larger” one, but to no avail.
Yes that’s worth a shot too Rob. I’ve been told though that because I’m not running 4pots that it should not be required…as demonstrated by Dave too I guess.
Maybe I’ll assemble all other options (rear calipers, M/S master cylinder, 304/295 disks) go on a trackday and change stuff till it works and then sell the bits that made no difference.
It might be me too I guess so maybe I should get someone else to drive…no don’t all offer
Ben
Cant see its discs for this problem.
I find if I go back out on track after a very short stop - say 10mins go back out I have a long pedal for half a lap but then it comes back. This is why Im convinced its a heat soak issue.
But I only have one star now so that bollocks
You’re welcome to take mine out if we’re at the same trackday mate… if it’s your driving style you should be able to get mine to do the same.
Really can’t see it being the discs.
Silly question, but you’ve got the discs fitted the right way around haven’t you?
Three stars now 
Yes agreed with your point about heat soak but why does it never return to normal once cool and why are others like Dave happy? Maybe its me… 
Thanks Dave - we should swap and you shoudl see if you can reproduce it on mine - you might get used to having the Jackson Racing Talent Enhancer tho
Yes the disks are the right way around…
Ahh OK it never comes back ?
You drove mine at Bedford right ?
Well those calipers are su#itting doing nothing … when MR E drops my car off at paint he could pick em up from my storage facility ?
No it gets better when cool but never returns.
Yes I drove yours at Bedford after it had been mapped but that feels like a very long time ago (must be a couple of years now)
If it’s no hassle to get hold of the calipers it’s got to be worth a shot even if nobody thinks it will make a difference huh?
Certainly worth a shot ! - I reckon it’s more chance of being the calipers than the disks!
Discs should be okay, pads should be fine as well.
If it’s the same fluid that Randy uses then again shouldn’t be a problem unless you are particularly heavy on brakes.
Really points to air in the system, assuming the rears are untouched then they shouldn’t suddenly be causing a problem unless you are having issues with the whole set-up and cooking the rear uprights and calipers.
You said you had the fronts refurbished, are you 100% sure they were done properly and they haven’t caught a seal somewhere?
Pretty sure Bens been having the problem for a while - so it’s possible one of the rear seals is buggered - but I’d have thought you’d be losing fluid if the seal wasn’t good ?
My bet is on a small amount of air in the system still - it explains why the pedal comes back if you leave the car for a while too. Still strange if both the Edwards and Randy has had a go at the car though!
Not sure if you’ve still got the standard setup with common clutch and brake fluid. If you have could the clutch system have anything to do with it? Has it been bled properly? Is the gearchange still good when the fluid is hot etc?
As I have but one star now my opinion is worthless - but rear caliper handbrake automatic adjustment faults can result in pedal travel issues…