Ha !!!
I did this to my ten year old Fz1s this week, no luck with allen type key,snapped that in one,so got the hammer and chisel and chipped at them until they started to turn,so then welded bolts onto two of them, got them all out, only one is re-useable, so today 6 rear and 5 new front oem bolts arrived from We-moto, so disk back on with greased bolts,,thefronts are good, had them off a few times when putting the wet wheels in
Needed to change the rear disc on the Gen 2 FZ1 and had been warned that it can be difficult to get the bolts undone.....
So soaked the threads in Plus Gas, froze the bolts (instead of warming the hub) to shrink them down, tapped them with large diameter pin punch to upset them and then tried to undo them...
2 undid ok, 2 T40 heads snapped off flush in the bolt heads and couldn't be removed, the other snapped off but did come out. What to do as the T40 heads are too hard to drill?
So welded M16 nuts to the bold heads and they undid fine with no damage to the hub (serious thermal shock helped). Not sure what else I could have done - may also work for the front discs as I've heard that the whole wheel gets thrown away if they can't get the bolts out.
The design of the bolt heads is wrong - the ratio of the T40 diameter to the bolt diameter means if the bolt is at all seized it's then very likely the T40 will fail - I used reasonably quality T40 heads...
...I think you might be mixing your metaphors.
Hi FZ1obp,
In your second picture it looks like there is red Locktite (Not sure what number the red Loctite is) on the screws you got out, but I understood that you should never use lock thread compound on any fixings that go into alloy threads, I'm not saying you did it, but it looks like someone did, a little bit of silicon grease or copper-slip is the best bet with steel fixings into alloy. just saying trying to be helpful :thumbup
...Helpful is fine, when it is helpful, but not so fine when you don't know what you are talking about and the advice you end up giving is dangerously wrong. You understood Locktite and alloy threads had a problem. You understood wrong. Locktite does not cause threads to shear, overtightening causes threads to shear, and greasing threads before attempting to torque them is a great way to ensure they are overtightened. The only problem associated with alloy threads is galvanic corrosion, which is a potential risk when ever two dissimilar metals (alloy or otherwise) are in the presence of an electrolyte. Locktite is not an electrolyte, copper-grease can be and introduces another metal to the equation. As for the brake disc bolts, the Yamaha Fazer 1000 service manual, Section 4, page 15, "Brake disc bolt", torque to 18Nm, LOCTITE. 18Nm is less that half the torque used on the caliper bolts. A quarter of the torque for the front axle and just over 10% of the torque for the rear axle. It is NOT VERY TIGHT! That is why you use locktite to ensure they stay in place. If you do them up like a gorilla, you will fuck the heads, you will fuck the threads, you will probably fuck the mount holes, and you will have problems removing them.
I never mentioned corrosion in my post (see above) all I said was 'I understood that you should never use lock thread compound on any fixings that go into alloy threads'
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But if you feel you need to use it on your brakes parts then that's fine.
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Anyway as I said at the end of my post 'just saying trying to be helpful '
If you really want to make sure they don't come loose you have a welder.
And if thread locking compound has no impact why use it, it does have impact it causes threads to shear off in alloy.