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Stripped rear brake master cylidner mounting bolts!!

4117 Views 41 Replies 11 Participants Last post by  Veefer97
I have an 06 gixxer k6 and I stripped the shit out of these bolts trying to get them off:

They're only supposed to be torqued to 7 ft-lb per the service manual. But with their thread lock and the fact that they haven't been touched since mfg of this motorcycle they're practically welded in there.

They have a 4mm hex head which is tiny and didn't stand a chance with the force to get these off. I rounded the hole and the hex grip is gone.

Now I dremeled a nice slit to fit a flathead screw driver, but these fuckers won't budge. The flathead is stripping the slit and I can't get any leverage. They're mangled now and I think it's time for a screw extraction.

So 3 questions:

1) Does anyone have the size spec of these screw threads (width, length & thread)? Specifically the width so I know what size extractor bit to use.

2) Do you agree that it's time for a screw extract? What product is best and where to buy? EZ out? Home Depot? Auto store?

3) Extra opinions on this matter

:comp FUUUUUUUUUCK! :comp
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Get a chisel and hammer. Hit screw so it will start to back off. Remove with screwdriver. EZ out will just break in there even if you do manage to get the hole drilled straight

that's a fat head, plenty of meat for a chisel. Maybe dremel a slot for the chisel if you can't get it to grab. bang along the outside of the head for max torque.

you can also shape the head so you can grab it with vice grips.
Penetrating oil can help too if you can get it to the threads. Hitting screws with a hammer can help dislodge them. So can temperature extremes.
Hopeless to give tried and true advice here. This method has worked for me countless times. You will need new bolts but by this time the bolts are wasted anyway
It's like an orange. I read about it on other forums. It's from Suzuki (not loctite) so it's probably not loctite red now that I think about it.

Nevertheless it felt like loctite WELD.

Back to impact drivers, what's their success rate? Do they damage the bolt even if they get it off? From what I saw on these bolts, I don't see how anything could've gotten it off and kept them in mint condition.

When I google impact drivers, there's plenty of info, but no real good illustrations of how they work - I'm not really understanding it. And some things say they're good for phillips head bolts but not so much on any other kind. Where are the facts?
As you hit the end with a hammer it applies force forward and a torque force. This will force the bit into the bolt and rotate the bolt. Once you crack it loose use a standard screwdriver/Allen wrench to get the screw out. Not a good application for your bolts as they are mounted on a somewhat flexible bracket and the bracket will absorb some of the hammer force. You could also bent the bracket
Absolutely does.

Do you have one more to get out?

I still vote you get a pocket butane torch from HD and gently heat it before turning it.
I can tell from your reply that you have never used such a device. It does not damage the screw if used properly.
The bolt looks like shit and reinstalling it damaged wont be good for future removal. I would use another. Structurally it might be OK but functionally its going to be pita.
The OP asked if the impact driver damages the bolt. Your reply was "Absolutely does". Well you are wrong as countles peolple have used this tool and did not damage the bolts
I was in HD the today grabbing some stuff and I decided to look at impact drivers. They don't have any manual ones. But they have a bunch of electric ones for unreasonable prices (except that cheap ass Ryobi one).

Are these electric ones even useful? Or the manual one is by far better?

So where are you guaranteed to find a manual one?
The electric ones only rotate. They are great on tight hex head boltsbut suck at taking out a philips. The maual type you hit with a hammer so it goes in and rotates at the same time. You need both. Treat yourself this Holiday season
I see a manual one at Autozone. Home Depot doesn't have manual ones. The manual at Autozone is $9.99.

The power ones are over $200. I'd like to be a big spender Veefer, but I'm just another American pauper in a country that's going down the tubes. All I have left is my gixxer with 2 broken bolts :lol

Winner...manual impact driver!!

Explain to me why I would need to spend over $200 for an automatic one?
They are great on nuts/bolts that are on a rotating shaft like the sprocket bolt or the clutch hub nut. You do not have to hold the rotating shaft as hard as the impact does all of the work. I work on bikes a lot so it gets used often.
It all depends on the situation. Sometimes you have to go with the big hammer/big hit as the screws are really tight. If the screws are on a flexible bracket you have to go easy as you could bend/break the bracket.
You know, I agree with you sport-ryder. The medium and light duty bolts on these bikes suck so much. I really only feel comfortable reusing the higher quality bolts with deep & large allens and square drives. You can tell a quality reusable bolt just by looking at it.

The light duty ones, like the ones I stripped (4mm allen heads) look like you can almost chew them like bubblegum. Obviously it held like a motherfucker, but the head is so soft and cheap, I feel like it's counter productive to have something hold so tight with such a fragile head.

The replacements for these bolts is under $2 from Suzuki (which is overpriced OEM) - so that's how cheap they are. I would almost be inclined to get replacements from hardware stores like you mentioned with better drives.

The only problem I have with hardware stores here in the states is that they have more SAE bolts than metric. So you don't have a lot of variety on the metric side of things. Damn founding fathers SCREWED us (no pun intended) :lol
Try I use them for all kinds of hardware and other bits and pieces. Great selection of SS Allen bolts. You get your parts within a few days. Good company to deal with. Their catalogue must be over 2000 pages
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