Rumbles after a few quick laps…clears once everything has cooled down…But seem to work OK when Rumbling ,no “High/hard Pedal”
Am running Original Equipment rotors with 1/4 worn Pagids RS 14’s
Maybe new rotors called for …what is the SIMPLEST replacement??
if your only using the car on track then its probably going to be a case of new rotors im afraid (i would also replace the pads if the ones on were past the half way mark).
However if your using it for road milage aswell you may be able to restore them after a couple of hunderd miles of general road usage with just normal application of the brakes. i’ve got away doing this once or twice now (i also whip the pads out, clean them up on somthing abrasive, usually the paddock tarmac and replace them in a differnt order to what they came out and let everything bed back in again. worth a shot before buying new rotors.
Thanks for that .
I will resurface the pads and give it another try…although I really only use the car for trackdays most of the mileage is done on the journeys to and from…we will see.
Is it not accepted wisdom that the standard rotors are made of cheese? I had exactly that problem and replaced them with proper ones…not saying I have not had continued problems…but not rotor based problems
Changed to SRF as the first possible cure, so not that.
I found one of the rear calipers jammed or very stiff on its sliding shaft.
After dismantling,cleaning resetting the pistons it is free , Will give it a test run tomorrow .and report.
So what causes the grumbling then? Is it heat glazing? If so would a quick rub of each disc with emery paper make the blind bit of difference?
Usually (but not always) caused by uneven pad deposits layed down from the pads to the rotors causing high spots (I call them high spots but were really only talking microns thick).
The correct process of bedding in pads and dics to each other is to lay a very thin (but even) layer of the pad material over the entire surface of the disc itself. Now if deposits start buliding up unevenly on the disc for what ever reason, as you brake and clamp the pads to the disc the uneven deposits on the disc sweep through the pad contact area giving you a rumbling on the pedal feeling. If you are using the brakes on the track and using them hard, everytime the uneven deposit sweeps through the pads that area of teh disc starts to get much hotter than the rest of teh disc and starts to pick up more material in a degenerative circle,
As I said if they have just started rumbling you may get away with a few hundred road miles to clean them up as they will be seeing no where near track operating temps.
If only for track use then you will probably find that by your 2nd session out when the whole system is at full op temp your brakes are jusrt as bad if not getting worse…
Is it not accepted wisdom that the standard rotors are made of cheese? I had exactly that problem and replaced them with proper ones…not saying I have not had continued problems…but not rotor based problems
Ive had the same trouble with std disc and Ap’s niether outlasting the other and from what I can tell no differnce in braking force so im back on the cheapo std items…
The RS14 PADS are a bugger for causing this. Especially if you don’t bed them in meticuluously.
I have switched to performance friction ‘race ready’ pads that officially you do not need to bed in and so far they’ve been great. No break judder or apparent disk warp after maybe 10 races. Outright braking performance seems comparable too.
I know the answer. Brake rumble is a precurser to…CRACKED DISCS.
So its a new set all round for me
AP’s…my RS 14’s are almost new ,can I use them on new discs??
I know the answer. Brake rumble is a precurser to…CRACKED DISCS.
So its a new set all round for me
AP’s…my RS 14’s are almost new ,can I use them on new discs??
Clive and i were discussing this yesterday at 120mph! Mine new EP’s rumble more, especially when hot. I have Pagid 42’s. Now wondering if I too have this cracking? Has anyone else experienced this? My pedal got really soft after a 25 min run yesterday, and is still the same today. I am somewhat unclear why?
It seems as if AP are the way to go… at least up front.