E36 M3 Evo brake problem

[benm3evo]

Hello.

I'm after a bit of help with a problem with my brakes on my M3 please.

When the brakes are hot (proper hot!) I get a very bad vibration when braking hard. It feels as though it's coming from the front drivers side wheel. Also after the hard braking, if I go around a fast left-hand corner (i.e loading up the front driver side wheel I guess) I get a sort of groaning sound which disappears quickly.

I'm thinking it's most likely a warped disk? But I just wanted to get further advice before I get them changed. Have jacked the car up & spun the wheel to try & check wheel bearings but there is no sound or vibration then.

Thanks for any advice!
Cheers, Ben

[e46m3c]

disk or bearing would be my bet as well.. My brakes used to judder/vibrate, changed the disks. sorted...

[RWDKurt]

Sounds like a disc problem to me too. It may not be warping as such but deposition, but the best fix is the same - new discs.

[benm3evo]

Thanks for the replies guys. I shall set about finding a new set of disks.
Cheers, Ben.

[helix402]

These calipers are prone to seizing with age. The problem first occurs when the brakes are hot. Does the car pull to one side? Is one disc noticably discoloured?

[benm3evo]

Hi. No it still pulls up in a straight line when braking, even when braking hard. Just get the shaking through the steering wheel. I've checked both disks & they're not discoloured or marked in any way.
To be honest, I tend to be a bit of a girl when braking so the pads or disks aren't badly worn at all & that's after 7 years! (only about 3-5k miles a year though).
Cheers.

[andygtt]

When I had a similar problem (4 years ago) it was down to a sticking caliper... didn't pull to one side but the caliper and brakes were getting silly hot on that side which was the give away.

my brakes have always had a wobble, it was down to using aftermarket EBC discs replacement discs and did it from the day I fitted them.... will never use aftermarket replacements again even if they are claimed upgrades with grooves etc.

[BJT]

I have a new set of EBC disks for the front if you are interested. I purchased them for my Evo but have decided to use the OEM ones.

[benm3evo]

Cheers for the replies.

I've spoken to my old man & persuaded him to strip it down next weekend & have a look at the caliper & disk etc to see if we can find out what the issue is.

Cheers for the offer of disks, I'll get back to you after we've next weekend & see if you still have them, obviously no worries if you manage to get rid beforehand.

Cheers, Ben

[e46m3c]

i had this problem when i bought my evo. It was fine braking, however when i got some temp in them they vibrated/juddered very badly. Everything looked fine, so changing the disks sorted the problem.

[M3John]

That to me ^ sounds like glazed disc's. Could be the OP's original problem as even if you DTI them they'll come up ok.

Edited for spoooooling !

Edited by M3John on Wednesday 30th November 19:30

[ecain63]

Its incredibly hard to warp M discs, you'd struggle to do it in race conditions. Vibration is normally caused by galzing or excessive wear. Have you checked the disc thicknesss? They have very fine tolerances and if they are even slightly under the min thickness they will wobble. You wont notice much of a lip around the edge even when well worn, thats how little you have to play with.

Eddie

[Output Flange]

Take the discs off and rub down both sides with emery cloth. The chances are it's pad deposits, particularly if you "brake like a girl".

[benm3evo]

Thanks for the replies.

I haven't checked the thickness of the disks properly with the wheels off, so this could be a possibility as I wasn't aware there isn't a lot of wear in these disks & they have been on there at least 6 years.

I'm hoping to rope the old man into helping me on the weekend so I'll check the ware then & also give them a rub down in the hope it's my girly braking causing the problem!

Thanks again, Ben.

[benm3evo]

Just an update for those interested...

Had the disks off today, couldn't measure the thickness accurately as didn't have the correct tool but the do look worn & were glazed. They also had a darkish coloured line about an inch thick (on both disks) around the disk & corresponding 'damage' to the pads so I guess this is where they've been getting hot??
Anyway, have cleaned the pads & disks up & just been for a test drive. It is a lot better but I'm thinking the original problem will come back.

Planning on taking it off the road after Xmas so think I will get new disks & pads next spring.

Oh one other thing, the brake pads are Predator which I've never heard of, did a quick google & believe they are made by Black Diamond. Just out of interest, anyone know if these are rated as good/bad/terrible!?

Thanks for all the help.
Cheers, Ben