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MX-5 brake disc removal - am I being stupid!?
chris68 - 2/4/14 at 06:22 PM

Hi guys,

Engine and gearbox out and now on the final stretch to complete the destruction but have come up against a prob. I have removed the complete front brake calipers and according to the Haynes manual it says remove the disc. How is the disc held on? Is it just a slide fit and everything is held together when the wheel is back on? I cant see any other fixings. Gentle tapping at the rear of the disc with a rubber mallet has not helped and heavier banging with a large hammer against a piece of wood has not helped? Is it just years of road crap and rust preventing removal? Am I doing something wrong?

Cheers guys.


coozer - 2/4/14 at 06:24 PM

Any little screws holding the disk?


Slimy38 - 2/4/14 at 06:27 PM

LOL, you've found the exact same situation I had!! From memory I found a way of hooking a bearing puller so it applied pressure to the face, wound it on and waited for the bang. There was no way the discs were going to come off with just a soft hammer!

As far as I could tell they didn't use the normal fixing screws (studs rather than wheel bolts makes alignment a bit easier), they had simply corroded themselves on to the hub.


rash12 - 2/4/14 at 06:43 PM

give them a good rattle they will come off


BigLee - 2/4/14 at 07:07 PM

Hammer the central hub part of the disc all the way around. (The rusty bit between the disc and the face the wheel bolts too) And I mean really hammer it! If your neighbours don't come out to see what the noise is, then you're not hitting it hard enough. Once you have gone right 'round, give it a hit from the back. It'll come off. It just needs persuading.


chris68 - 2/4/14 at 07:22 PM

I will try and raise the dead with the hammering then!! Its a relief to know I haven't missed a concealed fixing as I was expecting to find some screws holding the disc on.

Cheers all


adithorp - 2/4/14 at 07:26 PM

Sounds like the disc and hub flange have rusted together. As Lee says, hit the top hat all the way around until it comes loose. If it starts to come off then goes tight knock it back on and repeat as there's probably a rusty ring on the sides of the disc centre thats getting stuck behind the hub flange.

If in doubt... HIT IT!


BigLee - 2/4/14 at 07:38 PM

quote:
Originally posted by chris68
I will try and raise the dead with the hammering then!! Its a relief to know I haven't missed a concealed fixing as I was expecting to find some screws holding the disc on.

Cheers all


Speaking of concealed fixings, don't forget to use the Allen key to wind back the rear pistons. It's under a little yellow plastic cover. If you go old-school and force the issue, it'll strip the threads on the handbrake mechanism. Just a heads up!

Cheers

Lee


chris68 - 2/4/14 at 07:42 PM

Cheers for the heads up. I had noticed a different system on the rears but had spent most of the time cursing and swearing with the fronts!


nero1701 - 2/4/14 at 08:08 PM

Take the lot off in one go then have a crack at some electrolysis


nick205 - 2/4/14 at 08:17 PM

Are you wanting to reuse the discs? If not then a little heat with a blow torch may also help free the disc.


Dingz - 2/4/14 at 08:50 PM

Haynes says they 'slip off the wheel studs' no mention of a BIG hammer


chris68 - 2/4/14 at 09:13 PM

Yes that always makes me chuckle. When you look at the pictures for hub removal all the parts are nice, shiny and new not the rusted crud you often have to deal with making a simple job take ages.

I had thought of the blowtorch option but having a wooden floor that got soaked in oil and then some petrol I thought better of it!

The cap over the hub nut is also stuck fast but I guess some careful use of drifts etc will get that free (or hack it off).


indykid - 2/4/14 at 09:44 PM

There's an m8 tapped hole in each disc. Stick a bolt in and use it as a screw jack to separate the disc from the hub face. It's what it's there for.

It may still need a good clout, but it will be a lot more effective once the joint is preloaded with the bolt.


britishtrident - 2/4/14 at 09:47 PM

Most top hat style discs come off easily they either are retained by clips or countersunk screws but some types (for example Montego and Maestro) don't because the designer didn't leave enough clearance to allow for rust build up and no amount of hammering with a huge hammer will move them and you end up butchering them with an angle grinder.

You can buy specialist pullers for removing this type of disc but they cost.


snapper - 3/4/14 at 05:45 AM

Same thing happened on my 53 plate Mondeo
I had to heat discs very hot then use a 5lb club and a sledge to get them off
Ruined them


Slimy38 - 3/4/14 at 07:44 AM

quote:
Originally posted by britishtrident
Most top hat style discs come off easily they either are retained by clips or countersunk screws but some types (for example Montego and Maestro) don't because the designer didn't leave enough clearance to allow for rust build up and no amount of hammering with a huge hammer will move them and you end up butchering them with an angle grinder.

You can buy specialist pullers for removing this type of disc but they cost.


Thankfully the MX5 discs aren't that bad, once I'd got the faces separated I could see there was a good amount of clearance between the edge of the hub and the inner face of the disc. They did just fall off. And I'd decided beforehand that a new set of discs and pads would be a sensible expense so I wasn't bothered about the friction surface.


adithorp - 3/4/14 at 09:38 AM

quote:
Originally posted by snapper
Same thing happened on my 53 plate Mondeo
I had to heat discs very hot then use a 5lb club and a sledge to get them off
Ruined them


If Mondeo discs don't come off with a couple of hit we go straight to the cutting disc. They're the worst for corrotion behind the flange and not worth wasting time on... We have got very good at knowing where and how deep to cut before using a chissle to split the last bit.


chris68 - 3/4/14 at 06:29 PM

Update: Thanks to all the suggestions I have got the front discs off - cheers guys. Using a lump hammer and a piece of wood I hit the living daylights out of the area between the wheel studs and a gentle tap from the rear and the disc fell off.

I thought the hub nut was going to be a bugger but I found the offside was not staked and only took limited pressure to undo and although the nearside was staked it only required slightly more effort!!

To get the upright off I removed the lower wishbone through bolt and used a hacksaw to cut the upper wishbone, then pulled the assembly forward and tapped off the ball joints.

Hooray!! I've got all the bits needed for exchange.

Thanks again guys - no doubt I shall call on your knowledge again soon.


Slimy38 - 3/4/14 at 06:37 PM

On the subject of wishbones, I spent three hours detaching the front uprights from the various other parts.... and three weeks doing the same for the rears!!