Pulsating brake pedal/AP 4 pot discs and pads.

[cab260175]

Hi

I can feel the brake pedal pulsating when I brake very lightly (usually in traffic). I think that I have a warped disc that is knocking the pads back hence the pulsating. Under medium/heavy braking it is fine. I have taken the front wheels off and turned the hub by hand and the front right catches as you turn it. Is this a 'standard' characteristic of the uprated front brake kit?

I intend to change the front discs and pads, what make of pads do Caterham supply as standard and can anyone recommend any alternatives such as Mintex M1144?

Thanks

CAB

[redboy]

Hi... the pads for mine were supplied by CC in an AP Racing box with part# CP7600D46BX-M1142 on the box and MXD 1142 4317286P on the actual pads!
cheers, John

[F355GTS]

I would definitely uprate to 1144's. Discs are shockingly expensive though at nearly £300 a pair, you might want to get them skimmed, but before that check the front wheel bearings, if badly adjusted these can give the same feelings/ results

[Bafty_Crastard]

Have a look here......

[url]www.r300.net/index.php?name=PNphpBB2&file=viewtopic&t=722[/url]

Bafty

[cab260175]

Well, discs off and skimmed (£28/disc), new Mintex M1144 pads and a change of brake fluid. The pulsating in the brake pedal has gone and it stops smoothly from low speeds.

If anyone else intends to do this, ask to have the discs ground rather than turned/faced on a lathe as this takes off less material. The machinist that did mine said that the discs were only slightly out. Having it done has made a huge difference.

If you need to change the discs ask one of the independant specialists that advertise in the Lotus 7 Club's Low Flying magazine as they can supply discs cheaper than Caterham.

CAB

[incorrigible]

cab260175 said:

If anyone else intends to do this, ask to have the discs ground rather than turned/faced on a lathe as this takes off less material.

Lathing will take off he same amount if the machinist is being carefull

[cab260175]

I think you mean 'Turning' not 'Lathing'. According to the ex Rolls Royce machinist that I use surface grinding takes off less material.

CAB

[incorrigible]

I'll have to avoid the flying handbag, and stand corrected . But you don't need to have done a 5 year tool making apprenticeship to turn a brake disc

With either method you only take off the minimum material to make the disc flat. Any difference in amount of material removed should ne negligable

[finchy172]

Castrol SRF is the only fluid you really want to be using

[cab260175]

[quote=incorrigible]I'll have to avoid the flying handbag, and stand corrected . But you don't need to have done a 5 year tool making apprenticeship to turn a brake disc

Not intended to be a handbag Incorrigible, only useful information. Now you can walk into a machine-shop, have the minimum amount of material removed from your discs and avoid the embarrassment of being corrected.

[fergus]

it was probably more likely you had pad deposits on the disc. The degree of run out in discs is often negligable and on a vented disc rarely enough to cause pad knock back. Have you checked your hubs.

PS Finchy - AP660 is almost the same as SRF fluid but 1/3 of the price. Very few people require the absolute performance of SRF, especially in a Caterham where due to the open wheel design the brakes never get hot enough. Have hyperion done any testing of disc temperatures with disc temp paint?

[scooterscot]

Mintex Blue is more than up to the job if using 1144 pads.

[bertie]

fergus said:

it was probably more likely you had pad deposits on the disc. The degree of run out in discs is often negligable and on a vented disc rarely enough to cause pad knock back. Have you checked your hubs.

Mate of mine has exactly this problem on his car.

He's just swapped from standard to (second hand) uprated front brakes and gets the pulsing.

What do you mean by "pad deposits" and what would get rid of them other than skimming the disks?

[incorrigible]

WRT frequency of the problem, I've had 3 caterhams this year that had uneven discs. Standard ones are cheaper to buy replacements than skim the old ones BTW