Brembo Goldline Caliper - removing a seized pinch bolt

nighthog

A bit of a bike hacker
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Making a note of this here in case it helps others.

I've been gathering the parts to upgrade the front brake with a Brembo 4-pot Goldline caliper, as per Ducati Monster etc., but one of the pinch bolts holding the caliper halves together was seized solid. The bolt is a low-head M8 x 1.25 originally fitted dry by the look of the three that came out reasonably easily, but none of the usual removal methods including various combinations of gas torch heating, impact driver, soaking in PlusGas, slotting the now deformed head for a different impact driver bit, etc etc. moved the thing in the slightest.

Then it dawned on me that the threaded end of the bolt protruded maybe 1/2 a mm from the back of the caliper so if I could squeeze the bastard front and back so an impact driver bit would get a really solid hold, use the bit's hex to stop it turning, I could lift the caliper .... and it worked. It was crazy tight and I had to sit on the bench to stop it lifting but it went with a snap and I can now get on with the refurb.

If the bolt didn't protrude far enough I was going to find something as a little spacer between the bolt end and the vice jaw, but fortunately there was no need. Here's some pics of the Heath Robinson setup:

20220812_145840.jpg20220812_145912.jpg20220812_150101.jpg

I had got to the point where I'd run out of options and was going to drill the bolt out to weaken it's adhesion, which was always going to be a challenge as I don't have the right kit, and then had this idea.

And now I'm going to have a self-congratulatory beer.

Cliff
 
Making a note of this here in case it helps others.

I've been gathering the parts to upgrade the front brake with a Brembo 4-pot Goldline caliper, as per Ducati Monster etc., but one of the pinch bolts holding the caliper halves together was seized solid. The bolt is a low-head M8 x 1.25 originally fitted dry by the look of the three that came out reasonably easily, but none of the usual removal methods including various combinations of gas torch heating, impact driver, soaking in PlusGas, slotting the now deformed head for a different impact driver bit, etc etc. moved the thing in the slightest.

Then it dawned on me that the threaded end of the bolt protruded maybe 1/2 a mm from the back of the caliper so if I could squeeze the bastard front and back so an impact driver bit would get a really solid hold, use the bit's hex to stop it turning, I could lift the caliper .... and it worked. It was crazy tight and I had to sit on the bench to stop it lifting but it went with a snap and I can now get on with the refurb.

If the bolt didn't protrude far enough I was going to find something as a little spacer between the bolt end and the vice jaw, but fortunately there was no need. Here's some pics of the Heath Robinson setup:

View attachment 221695View attachment 221696View attachment 221697

I had got to the point where I'd run out of options and was going to drill the bolt out to weaken it's adhesion, which was always going to be a challenge as I don't have the right kit, and then had this idea.

And now I'm going to have a self-congratulatory beer.

Cliff
Like to see imaginative techniques used to resolve mechanical issues....
Had a nut to install on a threaded shaft protruding laterally in a deep recess (an outboard motor lower drive unit). The recess was much deeper than the longest wrench in the tool box....used a piece of stiff wire wrapped tightly around the flats of the nut to "hang" the nut in position while turning the lateral shaft... worked like a charm!
 
My method for stubborn internal hex ("Allen"/ "Unbrako") fasteners, is to get my Torx socket set, and find which Torx socket fits. Then grab the next size up, and hammer it into the bolt head. 9 times out of 10, this does the trick.
Also, I try to avoid regular Allen keys as much as possible, due to the "height" of the shorter leg. An Allen socket with a hinged breaker bar, or an extension+Ratchet will reduce or eliminate the sideways force/ movement that tends to cause the hex to slip.
 
Nice work @nighthog.
Where there's a will....
I 'm finding the milwaukee battery impacts really are the bomb for stuck bolts They tend to remove before the head strips out.
PS those milwaukee impact bit sets have very good metal they take a beating without rounding out.
Just lost a battle :shrug:yesterday, getting a TCI off a rusted hulk, had to drill the heads off the #3 screws. TCI still looked good inside. :pimp:
 
Stuff like this is why I'm such a big anti-seize fan. I put it on practically everything, sometimes even rub a little on my head, lol. Eventually, pretty much every nut and bolt on the whole bike gets it.
 
Stuff like this is why I'm such a big anti-seize fan. I put it on practically everything, sometimes even rub a little on my head, lol. Eventually, pretty much every nut and bolt on the whole bike gets it.
I am almost doing the same, except I use either anti-seize or a locking compound ("Loctite") on any and all fasteners or threaded fittings, at work and at home. Stainless nuts and bolts are notorious for seizing/ galling if assembled dry. And locking compound prevents this, while also reducing the risk of anything vibrating loose. At work, we almost exclusively use nylock A4 SS nuts, but still apply plenty of Loctite 243, for the reasons mentioned.
 
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