Brake disc replacement

[philharve]

Hi All

I was 'advised' following a successful MOT last week that I would probably require a new, rear, nearside disc before the next MOT. In the inspectors view the disc was pitted but not suffiently pitted to effect its braking performance which was spot on. The disc on the opposite hub, which I assume is the same age, is not pitted.

What causes pitting? If the pitting is light, assuming the disc is otherwise in good condition, would a gentle skimming rectify the problem? Or would replacement be the better option? Are discs expensive? Are they easy to fit?

I assume the discs on W202s. like most MBs, are separate from the hub and its a simple 'bolt on' job to replace them?

REGARDS Phil

 

[Yosser]

Hi.

I have just recently bought a 1998 C180 estate, and it needed disks all round.

I fitted these quite easily without any prior knowledge of the car - although a few years worth of skinned knuckles working on various other cars

In my opinion this job would be well within the grasp of a competent home mechanic, and the disks would be as well replaced as resurfaced. I think I paid about £20 each plus vat for rear disks. You will also require pads and a fitting kit. Be sure to know whether the pads are single or double pin - I think later cars had single pin (mine did).

 

[turnipsock]

Disks are quite cheap. It's just as much work to remove them to get them skimmed as it is to replace them. I think they cost £20-£25, I'm sure it would be at least £10 to get one skimmed.

There is a wear indicator on the disks that gives you an idea of how much life is left on the disk.

 

[television]

Hi All

I was 'advised' following a successful MOT last week that I would probably require a new, rear, nearside disc before the next MOT. In the inspectors view the disc was pitted but not suffiently pitted to effect its braking performance which was spot on. The disc on the opposite hub, which I assume is the same age, is not pitted.

What causes pitting? If the pitting is light, assuming the disc is otherwise in good condition, would a gentle skimming rectify the problem? Or would replacement be the better option? Are discs expensive? Are they easy to fit?

I assume the discs on W202s. like most MBs, are separate from the hub and its a simple 'bolt on' job to replace them?

REGARDS Phil

Good evening Phil, I suspect by your post that you are a light driver when it comes to breaking, big problem on all cars is that the rear only get 28% of the braking presure, this means that if you are a easy or soft driver, they will go rusty. A few hard stops could clean them up. they are cheap and easy to change, you just back off the parking brake, unbolt the caliper (2 bolts)
take out the set screw and pull off..
slight pitting will not fail the MOT, its only when the surface is in danger of breaking up.

if you choose to do it, it should take no more than 1.5 hours, You could have my phone number if you got stuck.

malcolm

 

[philharve]

... There is a wear indicator on the disks that gives you an idea of how much life is left on the disk.

Hi turnipstock

Have I understood you correctly? You mention a wear indicator on the DISC!!! Pad wear indicators, sure, but also on the disc?

REGARDS Phil

 

[philharve]

Good evening Phil, I suspect by your post that you are a light driver when it comes to breaking, big problem on all cars is that the rear only get 28% of the braking presure, this means that if you are a easy or soft driver, they will go rusty. A few hard stops could clean them up. they are cheap and easy to change, you just back off the parking brake, unbolt the caliper (2 bolts)
take out the set screw and pull off..
slight pitting will not fail the MOT, its only when the surface is in danger of breaking up.

Hi malcolm

Well, I think of myself as a fast driver but I've never attempted 3 figures in this Merc'. It feels as though it becomes a little tail happy as you approach the ton, the steering lightens and becomes twitchy, this forces me to back off. I don't know if this 'nervousness' is a C-class trait but I wouldn't put my C230K in the sportscar category even though it's fast. My previous car, a Toyota Celica, could easily exceed 100mph because its handling was better.

I brake lightly and early because I'm naturally cautious and because I anticipate road conditions. Consequently, I don't brake hard, except in an emergency.

I have always thought that an automatic would be heavy on pads but this doesn't appear to be the case.

Why should the nearside-rear disc become slightly pitted and not the opposite disc on the same axle? Doesn't sound like the effects caused by a gentle driving style to me. The front discs/pads are fine.

One again, the task of disc replacement appears straight forward. A 'one spanner' job in the Haynes manual.

However, I'm sure I pad a lot more than GBP20-30 for replacent discs on my Toyota. It seems some Toyota parts can cost more than MB parts.

REGARDS Phil