help req'd -Brake pads (MMC) - do they need changed?

r055 · Post by **r055** » Sat Nov 18, 2006 11:56 pm

Had a quick look at my brake discs and pads today before the sun went away along with the feeling in my fingers...

what depth should you be thinking about replacing the pads at?

i tried to get a photo of them, but focus was all out.

should I be thinking about replacing the discs/pads away from the MMC variety?

I'm going to give it another go tomorrow in daylight (if i can get the rest of the fecking lock nut covers off!!

robin · Post by **robin** » Sun Nov 19, 2006 11:04 am

You should replace when pad thickness below 2.5mm - note that the inside is often more worn than the outside ones you have shown.

If you have a caliper gauge with the pointy bits you can just about get it to measure the distance from disk to the pad backing plate without removing the pads IIRC, but the fronts are so easy to pop out, you may as well just pop them out and measure it the easy way

Cheers,
Robin

tut · Post by **tut** » Sun Nov 19, 2006 1:42 pm

And dont take chances with the pads getting too thin. Once your MMC disk is touched by a metal backplate, it is usually ruined.

tut

r055 · Post by **r055** » Sun Nov 19, 2006 5:10 pm

the driver's side front disc has, what appears to be a black patch as if the disc is slightly warped...
when you are turning the disc you can feel a bit more friction from the pads.
You can feel it when you are braking lightly coming to a halt at a slow speed, but doesn't pull to the side when braking heavily.

does this mean they are fecked?

what are my options for replacement - heard somewhere that they dont manufacture the MMC any longer...?

Stewart · Post by **Stewart** » Sun Nov 19, 2006 8:45 pm

r055 wrote:the driver's side front disc has, what appears to be a black patch as if the disc is slightly warped...
when you are turning the disc you can feel a bit more friction from the pads.
You can feel it when you are braking lightly coming to a halt at a slow speed, but doesn't pull to the side when braking heavily.

does this mean they are fecked?

Might be warped but make sure that it isn't worn wheel bearings giving similar symptoms. You should be able to feel this when the car is jacked up and taking a hold of the wheel and feel for movement.

I have never had MMC's but I believe they are very good in dry weather but you have to take care in the wet until you get some temp into them. There were some MMC pads available online. elisparts?
The thing I like most about MMC disks is that they always look new due to zero corrosion. They also don't leave horrible black brake dust on the wheels.

Rich H · Post by **Rich H** » Sun Nov 19, 2006 9:51 pm

They look minced mate!

Geary of Elise parts will sell you repacement pads but you could probably sell the MMC discs on SELCOCK or Pistonheads and fund a set of iron discs and pads from the proceeds.

Rich

Post by **simon** » Sun Nov 19, 2006 9:52 pm

Why replace them with iron ones? I thought MMCs were better (in the dry at least) and last far longer.

Rich H · Post by **Rich H** » Sun Nov 19, 2006 10:33 pm

Choice of pads and better in the wet.

They do last longer supposedly up to 100k but the mid-life failures look pretty terminal...

Only what I have read mind you....

Rich

r055 · Post by **r055** » Sun Nov 19, 2006 10:46 pm

what do you have on yours rich?

Rich H · Post by **Rich H** » Mon Nov 20, 2006 9:14 am

OEM Iron and green stuff pads. I don't drive hard enough (But I have cooked them a couple of times

)

A set of grooved discs and probably SBS will follow when they wear out. Originally I had MMCs on the front and Iron on the back, lethal combination by all accounts due to the different behaviors in wet/dry.

As has been suggested look for other causes of tight spots, wheel bearing being the most obvious. I would be inclined to take out all the pads to check them and then spin each wheel checking for wear in the bearings you can then also properly inspect the state of the discs. No great problem but you will need a 3mm punch for the rear pad retaining pin and either an expensive wind back tool or a pair of needle nose pliers to wind back the rear piston. The Elise repair manual tells you how.

You can also give all the rest of the suspension a good look over wile you are there, everything is fairly obvious and nothing should be hanging off, loose or leaking

mac · Post by **mac** » Mon Nov 20, 2006 9:34 am

The other thing to consider Ross is are you planning track use? We've had at least a couple of MMC failures on track - Simon Ironside & Tut spring to mind readilly when the bell and disc sheared apart.

Mac

r055 · Post by **r055** » Mon Nov 20, 2006 9:34 pm

i am considering it early next year, if i can get some training in before then, so wanted to get everything 'tip top'.

Also need to get a few PAX's in before then as i've never been on track at knockhill at all so don't know it - i do know the rally course, which i might end up in after that long straight!

Checked the nitrons out the other day - they look spot-on to the untrained eye.

However someone was asking on SELOC whether they should service their Nitrons

mac · Post by **mac** » Mon Nov 20, 2006 11:20 pm

Nitrons - if you can't see any holes in the piston body and the still click when you adjust then they are fine

Mac