SunnySideUp

... here goes ...

I did post this in the Brakes Forum, but it's dead in there So, risking abuse, here goes in NSR:-

Today I bought some Pads and Discs for the front of my old trusty MX5, yes - I know, I should have serviced my hairdryer at the same time!!

Anyway, I have replaced 100's of discs in my time as a car owner .... one of these discs has a chunk out of it.

This is not just any old chunk, it is a machined chunk .... like a flat across at a tangent of about 150mm milled out of the vent vanes. I only spotted the thing when I had assembled everything!!

However, this is the question:-

Could discs ever have a chunk milled out to balance them? Maybe it was way out and they removed some metal?

Personally, I have never, ever seen it .... but I cannot imagine how it passed inspection!?

Cheers, and don't laugh!!

The Dogs B******s

What a daft question

SunnySideUp

I knew I would get a fair hearing in here ............

FlightMan

Why is it a daft question.

Pete hasn't seen this on a disc before, and is asking for help on a car forum.

Seem perfectly reasonable to me.

what would scooby do

The discs on an mx 5 will never rotate fast enough for a balance issue to become noticeable

yoza

They are flats for holding in a machine whilst being processed.

They often balance a disc by adding springs to the vented flutes.

The Dogs B******s

JOKE,as Pete took it

FlightMan

Sorry, such a poor joke I didn't see it!

SunnySideUp

This isn't a machining flat .... interesting point on the springs, mind you.

The Dogs B******s

Surely you dont want me to explain it?


Just for you,Pete said,'This might be a daft question',and just as a joke,you know a bit of fun,i replied,'What a daft question',,,,,,,,,,,,,,do you get it?

yoza

Maybe the breezeblock crumbled..........

mart360

I think i know what your describing Pete,

can you post a piccy, so i can confirm it


Mart

SunnySideUp

It was getting dark when I spotted it ... I have put the wheels on and given it a drive, it is fine - pulls up square and true.

I'm going to ring the factors tomorrow - get another one, swap it over at lunchtime.

I just wanted an answer if they say something like, "It's a balancing flat, Sir" because I don't believe it is - I have never seen anything like it.

I will take a piccie if I remember when I take it off, before returning it to the shop.

What do you think it is?

mart360

Look at the disk in the link,

is that what your referring to?

http://www.alfaworkshop.co.uk/images...-134-1-800.jpg

Mart

dpb

Wouldnt you look at the said discs before installing them ..!?

SunnySideUp

That's very much like it .... but on mine the milling goes into the vent vanes partly. What's the explaination?

Couldn't see it while putting it on .... only came to light as I was cleaning the assembly oily marks off before putting the wheels on

I'm concerned that, as the years and corrosion gets to work, it will introduce a hot spot at this point ... warping the disc?

SunnySideUp

This is the page that photo came from ....

Alfa Romeo GTV Brake Discs

I can see no reason for why it should be like that?

Leslie

I have to say that I have never seen that before Pete. I think that what you said is probably the reason. I would not expect it to be a problem, can't see how it might pick up on the pads anyway. They often have grooves machined across the disk face radially and that is no problem either. I doubt that your disks would get hot enough to distort because of it either. If that is a radial distance of 150mm that is quite a chunk though. If it is the horizontal length of the machining thats not very much.

Les

SunnySideUp

Hi Les, it's the horizontal cut.

I have spoken to people today, and Ian Godney has responded on my Brake thread .. it seems that it is normal to have balancing cuts.

I'm off to the coast now with the top down .....

Leslie

Enjoy!

Les