Oh that's a bit hot mum

[rogerch]

Well I had a great run out today with a couple of friends, I hammered it hard all the way to the top of the mountain range. Then proceeded to do the same on the way down, now I must be fair, this was hard and fast and down hill, the brakes stood up to the abuse better and for longer that I had expected, but I had expected they would fail. And fail they did, at least I had warning and the pedal never went to the floor, just a failure to arrest speed. By the time the other 2 arrived I had pulled up and was stood watching the smoke billowing from the wheel arches, (nasty smell) These are the nasty single pot callipers standard on the 88 Stevens, so no surprise, the fluid used is Castrol Response Super DOT 4, new 2 months ago when I did the master cylinder, but clearly it has a boiling point lower than I would like. The pads are "Greens Tuff" and whilst the brakes could never be described as exciting they have been adequate.

Today was a rare occurrence, I've had the car 4 years, I knew I was pushing the brakes too hard, but if there's any knowledge out there about fluids with higher boiling points, pads that can better dissipate the heat I'd like to know. I'm not about to over react and start spending thousands on new callipers and discs, based on something I may never experience again.

(I did have fun though)

[Bibs]

Do you mean 'Green Stuff' pads? If so, they're bottom of the range of EBC pads and the range is defined by resistance to heat of the backing material. Greens should never be used on any car more powerful than perhaps 150bhp and can resist temperature conduction into the caliper up to 500 degrees. Red will resist up to 600 but yellow are good for up to 900 degrees.

A simple pad upgrade and you're done.

PS I get my info from the marketing director of EBC who is a fellow motorsport marshal

[rogerch]

Thanks Bibs, the pads have a green backing and there was a 'Green Stuff' brochure in with the stuff I got from Neil Hodson so I'm guessing that's what they are. I'll have a look on the website, but any knowledge of operating temperature window would be good to know. I may be a good thing that I'm known to be light on brakes.

[Bibs]

Get some yellows on there and cane the brakes as much as you like!

[rogerch]

Yes, I just read up on them, yellow looks good, I wanted to know about cold temperature efficiency and it seems good. I'll check out what's left of the ones on there tomorrow.

[910Esprit]

Well you're in luck, dot5.1 has a higher boiling point, however, I suspect you have not boiled 2 month old dot4, you have simply overheated the brakes. Have you tried the car with genuine Lotus pads? (No idea if theyr'e better, but they would clearly be a good reference).

[Sparky]

Laws of physics mate - you're dumping a huge amount of potential energy coming down a mountain. Doesn't matter what brakes you have, they're going to suffer! Done it often in the States on motors with monster brakes, and they all have a bad time.

[rogerch]

Well you're in luck, dot5.1 has a higher boiling point, however, I suspect you have not boiled 2 month old dot4, you have simply overheated the brakes. Have you tried the car with genuine Lotus pads? (No idea if theyr'e better, but they would clearly be a good reference).

I think you're right as I didn't loose the pedal, but even "stopped" the brakes would not hold it on the gradient, I had to put in gear to stop it rolling. Yes I was being a bad lad, accelerating out of the corners HARD, tacho and boost gauge off to the right, up a couple of gears, and then desperately trying to slow it down for the next one, down a couple of gears, snatch the last one to help turn it in, and we're talking about a 10 mile decent all twists and turns, I'm actually impressed the brakes lasted as long as they did. (Almost got to the bottom) But after a 10 minute wait they had cooled enough to continue, though with a bit more caution.

I was also pleased that for an old bloke, I'll be 61 on Monday, I out ran the other 2, one was a V8, both up and down, and there was no panic when the brakes started to go, I got it pulled up safely, hardly raised my heartbeat.

[DanR]

How often are you going to drive like that? Be honest with yourself. Hard or soft pads = costly rotor replacement or cheaper pad replacement.

As for a better fluid that's reasonably priced check this out:

http://www.penriteoil.com.au/products/specialty-automotive-products/sin_brake_fluid

[rogerch]

I inspected the pads today. Green Stuff has become Brown's Burnt !

But I am impressed by the brake balance in that the handbrake wouldn't hold it either, indicating the back had got just as hot as the front ! (wicked)

[Simon350S]

Sounds like a fun day out... Good work

If you've still got a firm pedal then you've not boiled the brakes as you would have got air in them...

Only ever boiled brakes once on my first ever Tarmac rally, fluid had boiled and spat itself out of the master cylinder, only used Castrol SRF since that day!

[dodge1979]

Im running yellowstuff on my s4. Now having never experienced the standard esprit brakes before, I can day if they are better than. The lotus pads. I have brembos on mine. ebc grooved anddimpled discs. The cold usage in these pads is poor. However,, two or three usages of the brakesand theyre warmed up. Then they are quite good. Have noticed that they work better on hard braking than round town stop p start. So my verdict it still out on these.it may be because of the silly abs system on my car. So on yours it could seem wonderfull! But unfortunately they will stop you when hounded them!

Sorry silly predictive text. Meant to say they will definitely stop you when you need them!

[rogerch]

Thanks for that, it could prove a bit of a problem, as I have a tendency to glaze brakes, by not getting them hot enough. So I could end up worse off with "Yellow", more research.

I've had the car 4 years, and OK it's only recently I got the handling to the point I can commit much harder to the corners, but I was coming down the side of a mountain, a long run, and I was expecting to the brakes to give out.

Of course the real answer is 2 sets of pads !

[red vtec]

Think you really need to upgrade the calipers, Yellow stuff pads will take higher temps but need more temp to start working. Alloy calipers will disapate the heat better in the first place, I replaced mine with a second hand set of Hispec and it's night and day on the brakeing. Or run some extra venting to the calipers to keep them in check.

My original calipers were binding on the rear, this boiled the fluid = soft pedal to the floor, that was a shock!!

You could look up Pagid pads they are supposed to be good, but will be same as yellow stuff with working temps.

[dodge1979]

I tend to be a bit of a gentle braker so maybe with my driving style the yellow stuff isnt suited