Noisy brakes when hot on track?

[colintinto]

Hi All,

When I was out at Knockhill on Saturday, after maybe 10 laps into my second session, I heard what sounded like quite a loud noise under braking into the hairpin. Sounded a bit 'grindy' if you know what I mean, but not quite metal on metal.

Did a cool down lap and headed in, and didn't go back out again as I didn't know the car well enough to say if it was a bad noise, or just one telling me it needed a rest. The last MOT had an advisory saying that the inner front pads were low, but that was only 2000 miles ago.

Took the front pads out on Sunday and yes, they are low, but maybe 2-3mm left on the insides. Brakes seemed fine on the way home too, so not sure what was happening.

Was I just reaching the limit of what are probably standard road pads? I noticed that the holes on the ventilated discs seem quite clogged up with dust too.

Time for a set of Carbon Lorraine RC5+s?

Colin

[Mike Scib]

Hi Colin, you may find that your pads are down to the rivet's that hold the pad material to the backing plates.



Also worth checking your rears

Mike

[campbell]

Sometimes the heat effect seems to make the brakes noisy, I can't really explain it but it has happened with mine occasionally. Might be down to the particular disc/pad combo?

Did you enjoy the laps you did have?!

[meatball]

Prior to your investigation I'd have guessed goosed inside pads.....
Any visits to the gravel?
Could you "feel" the noise through the pedal?

The clogged holes happens....some people clean them out with a screwdriver, others just upgrade the discs (I found grooved ones worked well) when the current ones are done.

The RC5's do seem to get a good write up.

[colintinto]

I did have fun before the noise

Couldn't see the rivets when I took the pads on the right hand side out, but didn't take the left hand ones out as I'd already decided I should get some new pads anyway.

How long should a set of disks last anyway? Did a very brief check with an old imperial micrometer and with a rough conversion they were around 24mm, and the service book suggests 24.9 as the minimum? Only done 23000 miles, but it might have sat around for a while, maybe got rusty discs, possibly even been skimmed?

Would grooved disks eat the pads more quickly?

Colin

[Kayfur]

There is apparently a misprint in the manual for the minimum disc thickness.

Should read :

New : 26.15 mm
Service Minimum : 24.0mm

More detail in this thread

http://www.scottishelises.com/phpbb/vie ... sc#p197963

Kevin.

[campbell]

Colin,

Obviously very dependent on usage, but I am now on my 4th set of front disks (including the ones on when new) and I'm nearly at 90k miles. The last ones went on maybe 15k miles ago (very rough...my records are in need of update!) and whilst we're just about to measure them pre-Spa, I think they will need changed next year.

So I'm in an approx 20k-25k miles service life for front disks, I'd say.

Rears are clearly a different story. My original rears came off at same time as the fronts to change to grooved ones, and since then they have been changed only once in about 70k miles and still have life in them yet

I do way less trackdays than many, although might be in a similar bracket to your car's previous owner.

The other thing is pad type, some of the EBC pads can really take it out of the disks.

EBC disks, on the other hand, have been great for me, and at £60-£70 each, I feel they are very good value. There are others out there (Elise Parts, as ever, for example) and I may also have a quiet word with Stu Pollock (Stu160) about his hand-finished items - not on general sale but I believe if you ask him nicely he may prepare you a set

Hope that helps a little.

Campbell

[IanD]

Interestingly I've had what sounds very similar with my S2 111s.

Has only happened a couple of times with me - did it on the SE run doing Dukes pass on each of the 3 runs we did about the same point on each run and probably 2/3 of the way through Duke's pass.
Fairly loud noise only on heavy braking more a thumping/grinding than just the grinding typically when pads get worn and seemed to disappear very quickly as soon as less heavy or no braking so seemed heat related.

Wondered if this was what people talked about as brake pad chatters/rattling so would be interested in others thoughts.

[j2 lot]

Wondered if this was what people talked about as brake pad chatters/rattling so would be interested in others thoughts.

Suspect what you/ they are referring to is when non OE pads that are slightly smaller or thinner are fitted they sometimes require backing pads to bulk out the pad so it doesn't rattle or move about in general driving. It goes away when you brake as the pads are pressed against the disc so can't move.

[simon]

Wondered if this was what people talked about as brake pad chatters/rattling so would be interested in others thoughts.

Suspect what you/ they are referring to is when non OE pads that are slightly smaller or thinner are fitted they sometimes require backing pads to bulk out the pad so it doesn't rattle or move about in general driving. It goes away when you brake as the pads are pressed against the disc so can't move.

The brake rattle happens when the pad backing plate isn't tall enough, not that the pad itself is thinner. You don't need a backing pad but an anti-rattle pad that sits above or below (or both as I have on mine) the brake pad in the caliper. It doesn't tend to be loud enough to hear at anything above 30mph ish though.

If you're getting brake squeal you can use pads or copper grease on the pad backing plate to help with that.

The pic below from the Eliseparts site shows the pads in place on a caliper.

[DJ]

Hi Colin
I ran the car with Pagid RS4-2's during the bulk of my ownership and for the track days I done except the first one. I put the old OEM ones back on a while ago when I returned the car to standard (removed Janspeed exhaust too.) Pagid's make a world of difference on the track and expect Lorraines will be the same. I did get same noise at same place maybe once or twice per trackday but always put it down to pushing a bit hard as it went away with a short rest and never had any after affects. Disks were never skimmed in my ownership and its definitely not the rivets appearing...... but guilty of car sitting around and lack of use, hence the sale

[DJ]

Colin - forgot to add a P.S.

My V5's arrived for my other cars today for my c of a. Elise slip was sent away in same envelope so you should get yours soon if don't have it already

[colintinto]

Hi Dickson,

You're right - the pads are not down to the rivets, just low, which you'd warned me about anyway.

Looks like the disks are about 24.4mm, so still got a bit of life in them. Going by what Campbell said they've done quite well.

V5 arrived yesterday too!

Colin

[campbell]

Looks like the disks are about 24.4mm, so still got a bit of life in them. Going by what Campbell said they've done quite well.

Yes and did you know that I am The Last of The Late Brakers too

[meatball]

Yes and did you know that I am The Last of The Late Brakers too

Or no braking....hence so little brake wear!