[Brakes] Strange T55? Caliper Bolts

[paraman]

       
After 9 years my front discs need replacing. got new discs and pads ready. (It is actually a Peugeot Tepee!) I was expecting normal T55 Torx bolts for which I have the correct socket. Much the my amazement I discovered they are bolts with a Torx shaped 'turret' which doesn't look too strong if the bolts are rusted on! Also I have never seen a socket that would fit around this oddball shape. The stupid thing is that there is plenty of space to fit normal bolts!
Has anyone come across these (2011) bolts and how did you remove them? Possible with a very tight wrench perhaps? I hope new replacements have a proper, normal bolt head!

[Gadgetman]

Those are eTorx.
You can find a socket set at most of the usual suspects.

It's commonly used on headbolts, so you might get to use them for something else later...

[paraman]

Those are eTorx.
You can find a socket set at most of the usual suspects.

It's commonly used on headbolts, so you might get to use them for something else later...

Went down on my ebike and found a place selling the female Torx sockets. I measured the E16 to be the nearest. A tight fit but probably better once I have given the bolts a good rub with a wire brush. Bike battery concked out on me on return at the bottom of the long hill home so home with part of the bike hanging out of the wife's Panda! Hope I never have to touch my head bolts! If only the electric Berlingo had a range of 200 miles and was affordable!!

[Tomcat3]

Give the bolt heads a sharp whack with a drift and big hammer to shock it then put the torx socket on and tap that on so it is seated good and solid.

[Gadgetman]

Went down on my ebike and found a place selling the female Torx sockets. I measured the E16 to be the nearest. A tight fit but probably better once I have given the bolts a good rub with a wire brush. Bike battery concked out on me on return at the bottom of the long hill home so home with part of the bike hanging out of the wife's Panda! Hope I never have to touch my head bolts! If only the electric Berlingo had a range of 200 miles and was affordable!!

Don't call them 'Female Torx' please. No one calls the other type for 'male Torx', either.
Call them eTorx.

I imagine that the reason they used these is that unlike regular torx, these doesn't 'fill up' with rock hard crud that is imppossible to remove. (They can be coated in crud, yes, but at least on these you can get to it)

The head botls are a completely different issue. Since they get a soaking of clean(ish) oil whenever the engine runs, they seldom have any crud on them. But there they're used more as a 'Are you certain you should be doing this' indicator. (They assume that hobby mechanics doesn't have the right sockets... )

Now that I think about it... maybe that's why they've used those bolts here...

[Zion]

Mercedes have used these bolts all over the car for quite a few years now. I think they give rapid purchase for a hanging torque tool in production mode with no chance of rounding off while trying to go quickly. And as you say, keeps the lightly-skilled tinkerers out of things.

[ffrenchie]

They are handy because when you have rounded them you can easily weld a big nut on top to get them undone with a hex spanner.