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CypherP

Original Poster:

4,326 posts

79 months

[news] 
Tuesday 9th October 2012 quote quote all
As the title says really. After 2 hours of both gentle and aggresive persuasion yesterday, I have a seized retaining bolt on the front nearside disc, that is both ground out and doesn't want to budge.

I have tried all methods suggested online, with the exception of drilling the head out and trying to remove the remaining thread. I've tried the double hammer method, impact driver and also using a hex punch to re-mould the bolt head, but the punch I have isn't steel and therefore is starting to disfigure.

Are there any other options I have left, or do I resort to drilling out the head so I can remove the disc and just go from there? I've also read that this retaining bolt is only there to stop the disc spinning when the car was being manufactured. Is this true, and if so, are they needed? I ask because the Brembos I have bought come with new retaining bolts and would like to use them if I can.

marcus85

152 posts

36 months

[news] 
Tuesday 9th October 2012 quote quote all
What car is it on? Can you post a photo?

Robb F

4,161 posts

58 months

[news] 
Tuesday 9th October 2012 quote quote all
The retaining bolt is not useful at all tbh. The disc is stopped from spinning by the four large bolts that go through it and the wheel, although it is useful when you change your brake pads (so not very often).
You could drill that sucker out in minutes and nothing bad will happen. smile

CypherP

Original Poster:

4,326 posts

79 months

[news] 
Tuesday 9th October 2012 quote quote all
It's on an E46 coupe. I'll try and get an image up a bit later, but its a hex screw that has been rounded out, so an Allen won't fit the head any more.

I'm going to go and buy a new set of Allen keys to do the other 3 later on, just getting so frustrated that the first disc I try to remove just wont budge!

marcus85

152 posts

36 months

[news] 
Tuesday 9th October 2012 quote quote all
You can normally attack the screw head with a chisel and pull the disc off. Should be able to get the remainder of the screw out with mole grips. Either that or melt it with a bit of heat (being careful not to damage the bearings). Put the new ones in with some copper grease and they will come out next time.
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Nick1point9

3,621 posts

67 months

[news] 
Tuesday 9th October 2012 quote quote all
CypherP said:
I'm going to go and buy a new set of Allen keys to do the other 3 later on, just getting so frustrated that the first disc I try to remove just wont budge!
Use an impact driver or you'll probably do the same to the other 3.

CypherP

Original Poster:

4,326 posts

79 months

[news] 
Tuesday 9th October 2012 quote quote all
The frustrating thing is that the first one I came to was already rounded off, so I'm hoping the others aren't either. I'm going to leave some penetrating fluid on them overnight and see whether it frees them up a little.

OlberJ

13,978 posts

120 months

[news] 
Tuesday 9th October 2012 quote quote all
Impact driver and when it doesn't work, drill them off.

If you leave the thread in then the disc will sit with the thread in the hole and not spin. It's not perfect but saves too much faffing about.

Left handed drill bits are also handy because when you hit a certain point they tend to unscrew themselves due to the heat and vibrations.

CypherP

Original Poster:

4,326 posts

79 months

[news] 
Tuesday 9th October 2012 quote quote all
OlberJ said:
Impact driver and when it doesn't work, drill them off.

If you leave the thread in then the disc will sit with the thread in the hole and not spin. It's not perfect but saves too much faffing about.

Left handed drill bits are also handy because when you hit a certain point they tend to unscrew themselves due to the heat and vibrations.
Thanks for this. I think this is the final plan this week when I revisit it. If they're not serving any further purpose being there, I'll drill off any that are stuck fast. I've already tried the impact driver route and no joy. The problem being that because the head is already rounded off, the impact driver has nothing to grip when turning.

I'll fire the drill up on Thursday and give it a go.

Mr2Mike

12,475 posts

142 months

[news] 
Wednesday 10th October 2012 quote quote all
Robb F said:
The retaining bolt is not useful at all tbh. The disc is stopped from spinning by the four large bolts that go through it and the wheel, although it is useful when you change your brake pads (so not very often).
It also prevents the disc moving when you remove the wheel, with the possibility of crap (corrosion etc.) falling between the disc and drive flange. So quite useful in fact.

jeoff82

103 posts

77 months

[news] 
Wednesday 10th October 2012 quote quote all
The retaining bolt always seemed to get seized on them BMW's. I always drill them out but if i recall the bolt is quite large so need a largish drill bit.

mk2 24v

298 posts

51 months

[news] 
Wednesday 10th October 2012 quote quote all
impact driver has always worked for me biggrin

or if the discs aren't being reused, just beat the st out the back of the discs to break the head off the retaining bolt smash

Robb F

4,161 posts

58 months

[news] 
Thursday 11th October 2012 quote quote all
Mr2Mike said:
It also prevents the disc moving when you remove the wheel, with the possibility of crap (corrosion etc.) falling between the disc and drive flange. So quite useful in fact.
Is taking an extra 10 seconds to wipe the face when you take a wheel off really worth the effort of struggling with a seized bolt?

If you really want to keep it you could simply install a helicoil after you've drilled it out.

Mr2Mike

12,475 posts

142 months

[news] 
Thursday 11th October 2012 quote quote all
Robb F said:
Is taking an extra 10 seconds to wipe the face when you take a wheel off really worth the effort of struggling with a seized bolt?

If you really want to keep it you could simply install a helicoil after you've drilled it out.
If you can remove the caliper, caliper carrier and disc in 10 seconds then certainly, but that's beyond the capabilities of almost everyone I should think.

Once the screw is replaced with copper grease applied to the threads they are easy to remove in the future.

CypherP

Original Poster:

4,326 posts

79 months

[news] 
Thursday 11th October 2012 quote quote all
jeoff82 said:
The retaining bolt always seemed to get seized on them BMW's. I always drill them out but if i recall the bolt is quite large so need a largish drill bit.
I'll likely be drilling it out, and have now bought some better quality allen bits to remove the others, so hopefully they won't get stuck either. I have a nice new tin of copper grease to ensure I don't run into the same problems a year or two down the line.

lexusboy

937 posts

30 months

[news] 
Thursday 29th November 2012 quote quote all
Are you changing the disc?

If you are, just get a big hammer and smash the disc off from behind, if you've damaged the head of the screw enough it will be soft enough to bend out the way then you should be able to get some molegrips on the stud and remove it that way

jasesapphy

649 posts

96 months

[news] 
Monday 17th December 2012 quote quote all
8mm drill and 20 seconds job jobbed, new bolts are £1.59 from bmw

BliarOut

60,052 posts

126 months

[news] 
Monday 17th December 2012 quote quote all
lexusboy said:
Are you changing the disc?

If you are, just get a big hammer and smash the disc off from behind, if you've damaged the head of the screw enough it will be soft enough to bend out the way then you should be able to get some molegrips on the stud and remove it that way
fkadoodledo, remind me NEVER to buy a car from you yikes

Jazoli

4,486 posts

137 months

[news] 
Monday 17th December 2012 quote quote all
BliarOut said:
lexusboy said:
Are you changing the disc?

If you are, just get a big hammer and smash the disc off from behind, if you've damaged the head of the screw enough it will be soft enough to bend out the way then you should be able to get some molegrips on the stud and remove it that way
fkadoodledo, remind me NEVER to buy a car from you yikes
+1 from me, why bodge it when it can be removed properly in the same time with minimal effort rolleyes


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