Finaly replaced disc locating screw

[CJJ]

While I had the rear offside brake stripped to sort out the stick handbrake, I decided to drill out the broken disc retaining screw.



I bought 8 stainless screws off e-bay before christmas, and they have been sitting in the garage since.

After removing the disc (see here for further details http://forums.mg-rover.org/showthread.php?t=199027 or here fro the front discs http://forums.mg-rover.org/showthread.php?t=197579) it revealed the broken screw.

A nice heavy blow with a centre punch will provide the start for the drill and may even free the threads up a little.





The next step was to drill down the centre of the screw



to allow access for the screww extracor. For those of you who have never used one of these, it is a bit like a big self tapping screw with the opposite thread to that which you are trying to remove. You tighten it into the hole, screwing it the opposite way to tightening the screw, and the theory is that it bites in and undoes the remains of the screw. That is the theory, but it very rarely works, unless the screw is fairly loose in the first place.



So, that didn't work. Don't apply too much force as the extractors are hardened and brittle. If they snap in the hole and cannot be removed you are stuffed as you cannot drill these.

The next step was to use a bgger (5mm) drill)



and tap a 6mm thread which is the normal thread of these bolts. This could work, or could end up a mess as you are tapping a 6mm thread into an existing 6mm thread and could just end up stripping out the existing thread. It is worth a go, as the next step would be drilling a larger hole and tapping and fitting a larger, non standard, screw.








Well, the operation was a success. I now have 2 nice new stainless screws in the rear offside disc.



Now that just leaves the other 3 discs.

[Herbie]

Quick, hide the
WD40
before Chris / Pete spot the tin

Nice work, bet you feel a bit better now ...

[Petevick]

blimey, you've been a busy boy

[shonky-25TD]

HMMMM i had recently posted another thread about a similar screw but on the drums. I certainly didnt realise you could simply re-thread the hole the same size, as per your post i thought it would just disintergrate. Now i no you can im not so fussed that i may have to drill out the screw.

Thanks for this post, it has helped loads.

[Chris T]

Great how to, must do the screws for the O/S front disc.

[Petevick]

Originally Posted by Chris T

.....must do the screws for the O/S front disc.

we could have screw removal day, both my rears need doing

[rossocorsa]

did my front discs and pads (APs)last week got two screws out no problem with air impact other two decided to sheer off half way out, drilled tehm out and retapped threads as per above was absolutely fine in the end! Pins in the calipers were another issue lots of cussing and swearing anyway a tip on these get some wet and dry and sand the pins whilst in situ to remove as much rust and crap as possible otherwise they come partly out and then get stubbornly stuck as i found to my cost! got it all done in the end though !!!!