Changing Front Discs and Pads

[Cunning Plan]

Anyone had a disc ceased on?

Changed them on the Mondeo today, the first side took about 30 mins including putting wheel back on etc.. The passenger side took 2 hours!!!!!! Had to grind the disc off as it was so welded onto the hub - I was hammering it but ran out of bigger hammers!

[art b]

they can seize on,
then have to be broken into pieces to be removed....

[Cunning Plan]

Quoting: art b

then have to be broken into pieces to be removed....

How do you break them into pieces - grind too?

I didn't like grinding it as I didn't want to cut into the hub

[art b]

i havnt done it,
but a large hammer will shatter a cast disc...

[Cunning Plan]

Quoting: art b

but a large hammer will shatter a cast disc...

Hmm yah, I think I need a bigger hammer

[Andy]

Fecking hell CP! Them are floating discs on the hubs, how did it seize on? Do you mean rusted the underside to the hub?

[Titsy]

I had the same problem on the Focus a while back... tried all sorts, but 25-30 mins with a blow torch heating the disc did it in the end...

I'd be dubious about hitting it so hard that the disc shattered as it's most likely going to put the steering geometry out of alignment...

[FUBAR]

Quoting: Titsy

put the steering geometry out of alignment...

at least that can be reset.
Thats still a pretty extreme measure tho!!

[Cunning Plan]

Quoting: Andy

Do you mean rusted the underside to the hub?

Yep

Quoting: Titsy

I had the same problem on the Focus a while back... tried all sorts, but 2-30 mins with a blow torch heating the disc did it in the end...

Yah, I tried heating it but was running out of gas in the small hand-torch I had.. I think when I started grinding - that transfered alot of heat into the disc and helped free it up. Still rediculas though!

What I did notice though is that the wheel bolts can be hammered backwards out of the hub - not sure if that would have freed it up a bit more

[philoldsmobile]

Quoting: art b

i havnt done it,
but a large hammer will shatter a cast disc...

Urban myth..

You wont shatter the disc, no matter what you hit it with. When I did my apprenticeship the company I worked for traded under the name Kelgate - we made Kart brakes, with cast iron discs.

On our display stand was a cast iron brake disc that was bent over in half, to illustrate exactly that point - the material bends rather than shatters.

When a cast iron fitting breaks or shatters its because its low grade iron, suffering from nitrogen embrittlement - this is due to the way its cast, rather than the material itself.

The iron used in brake discs when cut open isn't full of holes and bubbles, its consistent right through like steel, the only difference being its a dull grey colour (as opposed to bright silver) and a surface coating of graphite dust.  When machined, the swarf forms tight curls, with a slightly rough surface, and lots more graphite dust is released. Because of the structure of cast iron, no chip breaker is needed on the tip.