325i Rear brake discs stuck (pics) - Please help !!

Sat Oct 21, 2006 5:42 pm

Hi all

I'm new to the forum but I hope somebody can help me !

I have a 1985 German (imported) 325i and I am trying to replace the rear pads and discs as the car has been sat in the garage for two years while being off the road.

Now I got the wheels off without any problems, along with the caliper, but I absolutely CANNOT budge the Allen nut that locks the brake disc in place......I shredded an Allen key trying to get it out, and so I went and bought an "impact driver" which also did absolutely nothing to loosen the bolt.

I then attempted to drill the bolt out using a HSS drill bit, but to no avail.....I drilled for over an hour and it merely ground a couple of millimetres into the hole..It appears that the bolt is made of some kind of indestructible substance.

So I went out this morning and bought a new, more powerful drill, a blowtorch, and a bolt extractor and set to work.

The bolt extractor couldn't even bite into the bolt.

Blasting the bolt with the blowtorch repeatedly in an attempt to soften it has done absolutely nothing whatsoever, and drilling it for 45 minutes with the new drill has served only to break two drillbits and get about another millimetre into the hole.......

What I want to know is if it is possible to get the disc off any other way ?

Is it possible to remove the whole fitting and just replace that ?

Many thanks to anybody who helps !

Sat Oct 21, 2006 5:52 pm

If it was me?

Id remove the caliper mounting,rotate the disc so the allen bolt is opposite the caliper position,then smack the disc off with a hammer which will probably shear of the disc but leaving the bolt in place,then use some decent mole grips to remove the bolt,worked for me before,as long as you understand my explanation?

Oh and welcome to the zone

Sat Oct 21, 2006 6:22 pm

Hi eko.

Many thanks for the reply mate

I'm not sure what the caliper mounting is ?....

At the minute, the disc itself doesn't move more than about a quarter of an inch either way, but I have tried smashing the hell out of the area immediately around the hole that the bolt is in, in the hope that I can somehow dislodge it, but to no avail

Sat Oct 21, 2006 6:34 pm

Caliper mounting is the bracket on the left of the disc,think its 2 19mm bolts hold it on.
Disc should turn unless youve got it in gear?
If it is to stiff to turn,you could try putting 2 wheel bolts in and using a large screwdriver between them to turn it!

Sat Oct 21, 2006 7:02 pm

I think I know what you mean now mate.....so I should turn it round so that the bolt is on the left side of the disc when I am facing it, and then hit the disc from behind with a hammer ?

Sat Oct 21, 2006 7:08 pm

Turn the disc until the retaining bolt is at 180 degress from the caliper and belt it from behind with a dead blow hammer or lump hammer using a cloth over the disc.

Sat Oct 21, 2006 7:09 pm

no,looking at pic 4 above,turn it so the bolt is at 3` 0 clock and hit at 9` o clock,from behind of course1

Sat Oct 21, 2006 7:11 pm

Yup thats exactly what he means mate, smack seven colours out of it from behind. Looks like it wont take much smackin with the nick of the screw

Sat Oct 21, 2006 7:11 pm

Right I'll give that a go tomorrow.....Many thanks to you for your help

NB: Once I have the new discs on, it is my understanding that I won't need to re-fit any new retaining bolts....Is that right ?

Many thanks again.

Sat Oct 21, 2006 7:12 pm

eko wrote:no,looking at pic 4 above,turn it so the bolt is at 3` 0 clock and hit at 9` o clock,from behind of course1

Of course

Sat Oct 21, 2006 7:12 pm

I'm with eko on this 100%.

Sat Oct 21, 2006 7:14 pm

Yep, sorry, didn't see the pics

Sat Oct 21, 2006 8:20 pm

tomsimpson22 wrote:Right I'll give that a go tomorrow.....Many thanks to you for your help

NB: Once I have the new discs on, it is my understanding that I won't need to re-fit any new retaining bolts....Is that right ?

Many thanks again.

Thats right mate, all they do is hold the disc in position untill the wheelbolts are tight.

A lot of cars don't have them at all

Sat Oct 21, 2006 9:29 pm

Fit some new bolts, but a good tip is to smear the threads with some copper grease, and don't go mad tightening the new bolts.

And yes, a hammer is the answer! Worked for me numerous occasions in the past, and even broken a few discs.

Once the disc is removed, a pliers will sort out what's left of the bolt.

Sun Oct 22, 2006 1:42 am

And if the mole grips dont do the job, 'warm' the area of the hub around the bolt, trying not to directly heat the bolt itself. Then it should come out no worries.

I had the same trouble as you a couple of weeks ago, but the opposite way around. The hex head was stripped out. Gave it a clump and the disc popped off with the bolt a a fragment of disc left behind.

Sun Oct 22, 2006 1:51 am

This is a rear caliper. Don't forget there are brake shoes inside the middle, which have possibly seized on.
Before attempting to smash the disc off, i would back the handbrake cables right off at the brake lever, and back the shoe adjusters right off inside the hub.

Sun Oct 22, 2006 2:14 pm

If you are binning the discs use a grinder to grind the head of the allen bolt off down to the thread. Always worked for me.