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[Kevin Wood]

I should add that after that happened to me, I found the rear pads were knackered, so the rear was probably not doing much braking. IIRC, I had pretty new TC pads and disks on the front.

[omega3000]

They can't take the repetitive big stops. Feel I guess is a personal thing, to me they feel dead generally. Oe make them feel less dead, and give an improvement, but as TB says they just can't take pre longed "proper" use.

Bigger swept area, bigger diameter discs maybe. With a twin pot set up? 18's give scope there.



Edit to add, ebc discs on mine currently. Suspect less bite. GM going back on soon as a comparison. If the pads aren't cooked, it "might" be a fair comparison.

I'm a bit concerned about where you said yours faded last weekend - you had a long period of little use (35m), then 4 roundabouts within a mile, 3 are big stops, 1 is a little stop, then about 3m of little use, followed by a big, big stop, and the brakes were gone by the next big stop a mile further on.

Even when really trying, its not something I have suffered from on that stretch, although I know Kevin Wood has.

Hence my feeling that maybe either the EBC discs are pants, or you have another problem. Have you had that happen there before, pre EBC discs?

I'll admit mine are hot by the time I get to the next roundabout along, which is another big stop, if I'm going for it. To the point of lots and lots of smoke pouring off them. But no real fade - a slightly different feel maybe, harder? But not faded to the point of beginning to lose confidence they will slow you down fast enough.


Thinking aloud, my pads are (normally  ) binned at about half worn on the front. Are your pads low? There don't seem to be able to lose heat when worn.

 

Note to self : must try harder 

[feeutfo]

They can't take the repetitive big stops. Feel I guess is a personal thing, to me they feel dead generally. Oe make them feel less dead, and give an improvement, but as TB says they just can't take pre longed "proper" use.

Bigger swept area, bigger diameter discs maybe. With a twin pot set up? 18's give scope there.



Edit to add, ebc discs on mine currently. Suspect less bite. GM going back on soon as a comparison. If the pads aren't cooked, it "might" be a fair comparison.

I'm a bit concerned about where you said yours faded last weekend - you had a long period of little use (35m), then 4 roundabouts within a mile, 3 are big stops, 1 is a little stop, then about 3m of little use, followed by a big, big stop, and the brakes were gone by the next big stop a mile further on.

Even when really trying, its not something I have suffered from on that stretch, although I know Kevin Wood has.

Hence my feeling that maybe either the EBC discs are pants, or you have another problem. Have you had that happen there before, pre EBC discs?

I'll admit mine are hot by the time I get to the next roundabout along, which is another big stop, if I'm going for it. To the point of lots and lots of smoke pouring off them. But no real fade - a slightly different feel maybe, harder? But not faded to the point of beginning to lose confidence they will slow you down fast enough.


Thinking aloud, my pads are (normally  ) binned at about half worn on the front. Are your pads low? There don't seem to be able to lose heat when worn.

Wonder if depends from what speed?(obviously it will , but maybe that's the difference we're seeing) I haven't got round to replacing the fluid with 5.0(or whatever it is that can mix with 4.1) yet. But I don't recall much difference in peformance on that stretch. Maybe the fade came in a little early.

Fluid change perhaps but the underlying trend is "Gay brakes"

[feeutfo]

Not sure expecting to keep up with two tvr's is fair though, tbh.

[Kevin Wood]

But no real fade - a slightly different feel maybe, harder? But not faded to the point of beginning to lose confidence they will slow you down fast enough.

That's about the point where I was, TBH. Could tell they were getting hot, so backed off, as I'm not sure how much I had left.

Wonder if depends from what speed?(obviously it will , but maybe that's the difference we're seeing) I haven't got round to replacing the fluid with 5.0(or whatever it is that can mix with 4.1) yet. But I don't recall much difference in peformance on that stretch. Maybe the fade came in a little early.

Fluid change perhaps but the underlying trend is "Gay brakes"

Energy is proportional to the speed squared, so very dependant on speed.

DON'T use DOT 5! DOT5.1 is a superior spec mineral fluid, compatible with DOT4 but higher boiling point. DOT5 is silicone fluid that I would personally only put in a brand new system, and even then I'd say it has some nasty properties that make it unsuitable for a road car.

If fluid were the problem you wouldn't have fade, though. loss of pedal feel, sponginess, sudden total loss of braking, perhaps, but not just fade.. IME.

Not sure expecting to keep up with two tvr's is fair though, tbh.

You need something lighter to do that.

[Lazydocker]

But no real fade - a slightly different feel maybe, harder? But not faded to the point of beginning to lose confidence they will slow you down fast enough.

That's about the point where I was, TBH. Could tell they were getting hot, so backed off, as I'm not sure how much I had left.

Wonder if depends from what speed?(obviously it will , but maybe that's the difference we're seeing) I haven't got round to replacing the fluid with 5.0(or whatever it is that can mix with 4.1) yet. But I don't recall much difference in peformance on that stretch. Maybe the fade came in a little early.

Fluid change perhaps but the underlying trend is "Gay brakes"

Energy is proportional to the speed squared, so very dependant on speed.

DON'T use DOT 5! DOT5.1 is a superior spec mineral fluid, compatible with DOT4 but higher boiling point. DOT5 is silicone fluid that I would personally only put in a brand new system, and even then I'd say it has some nasty properties that make it unsuitable for a road car.

If fluid were the problem you wouldn't have fade, though. loss of pedal feel, sponginess, sudden total loss of braking, perhaps, but not just fade.. IME.

Not sure expecting to keep up with two tvr's is fair though, tbh.

You need something lighter to do that.

Certainly what I experienced when I boiled the fluid on the estate when test driving it

[Shackeng]

Just to clarify, what is the definition of a 'big stop'? Is that stopping using maximum braking 'just for fun' ? Or just what may occur if you fail to drive according to road conditions?

[feeutfo]

Ahem, movIng swiftly on.

What's the options then, and I don't really buy the GTO upgrade thing.

[twiglet]

I'm gonna stick my twopenneth in here, and I fully expect to get shot down for it...

Reading through the posts on this thread, particularly from the TB, talking about big stops from 3 figures, from roundabout to roundabout around MK, trying to find out what when the brakes on you circa 2 tonne lethal weapon might decide they've had enough... What the hell are you playing at?

I believe you have posted an awful lot about a certain Rover 25 that is no more, due to someone piling into the back of it, and the subsequent health issues you have suffered as a result...

All I can say is, I hope to fack, that I'm not sitting at a roundabout in MK, with my 11 month old daughter in the back of my car, next time you decide to performance test the braking power of your car!! 

I have a 3.2 Omega Elite estate (basically the heaviest version made) with the standard GM brake setup... It serves me perfectly well at sensible driving speeds on public roads... If the situation arises where I need to anchor up, then once again, it performs perfectly well, and I always have one eye in the rear view mirror, to make sure the fella behind me can stop as well as me.

If you are finding that your driving style is out-performing you brake setup, then can I respectfully suggest that you take yourselves off to an empty race track or airfield, an keep off the public highways where you could end up killing someone.

[Omegatoy]

wouldnt mind betting all those that suffer from boiling brakes are auto?

[Andy H]

How long (in years?) since the last full fluid replacement?

DOT 4 is hygroscopic. Car braking systems don't seem to be sealed (unlike motorbikes) so moist air gets into the fluid reservoir and slowly increases to water content of the brake fluid.

Old fluid, containing water, has a much lower boiling point than clean fluid (but I expect that everyone reading this already knows that.............)

[biggriffin]

I'm gonna stick my twopenneth in here, and I fully expect to get shot down for it...

Reading through the posts on this thread, particularly from the TB, talking about big stops from 3 figures, from roundabout to roundabout around MK, trying to find out what when the brakes on you circa 2 tonne lethal weapon might decide they've had enough... What the hell are you playing at?

I believe you have posted an awful lot about a certain Rover 25 that is no more, due to someone piling into the back of it, and the subsequent health issues you have suffered as a result...
 

All I can say is, I hope to fack, that I'm not sitting at a roundabout in MK, with my 11 month old daughter in the back of my car, next time you decide to performance test the braking power of your car!! 

I have a 3.2 Omega Elite estate (basically the heaviest version made) with the standard GM brake setup... It serves me perfectly well at sensible driving speeds on public roads... If the situation arises where I need to anchor up, then once again, it performs perfectly well, and I always have one eye in the rear view mirror, to make sure the fella behind me can stop as well as me.

If you are finding that your driving style is out-performing you brake setup, then can I respectfully suggest that you take yourselves off to an empty race track or airfield, an keep off the public highways where you could end up killing someone.

  I would like to 2nd the above motion,

[feeutfo]

Aaaah it's always good to upset the 10 to 2 bregade.  

[2woody]

The brakes are certainly very marginal in normal conditions. Ok, I do live up in the hills, but I'd really expect a set of discs to last me more than six weeks or so. The real problem is that the Girling calipers are working at their absolute maximum potential to stop a car with reasonable (but not great) performance on 300mm discs. When they get hot, you tend to get vibration, which kills the discs - this happens every day on my return home from work.

The only solution is larger discs, which in turn means bigger wheels ( but seeing as most of us run 17's it's no problem )

In the days when I ran 300mm discs on the track-day car, even with yellow-stuff, I'd get maybe a half a day out of new ATE-branded discs.

I do have a car with 350mm discs, which were fitted two years ago and have done over 10,000 road and 2000 track miles, still on the original pads. Once I'm sure that they are suitable and that I have re-engineered the rear as well, then I'll publish the solution for others to follow.

[2woody]

Oh, yes and I'm with you on the GTO solution as well. I have a car on those brakes, and can honestly say that it's the only thing I've driven which makes the Omega brakes look good. They are no greater capacity.

Incidentally, the brake setup on the Holden GTS ( APs ) is really good on the road - I simply can't put enough work into them to get them warm. On the track, tho it's a bit poo. I need to do some work there.