How to dissasemble Fs1 square caliper 3E8

[juhl-drengen]

Hello i have a Square brake caliper im wondering how to dissasemble it (the mounting part) is it like screwed in or is it just pushed in so i have to beat it out with a hammer or what?

Regards Kevin - Denmark

[NIX]

Do you mean the caliper of the pump? Before I start spending time explaining the wrong item. Use pics.

[juhl-drengen]

As you can see the bolt/thread there usually is have been cut off..

I Wonder how i can get the Mount out of the caliper so i can glass blast the caliper and fix the Mount with a new thread..

[NIX]

Ok. The aluminum cilinderblock should be able to turn a bit around the iron pin. Due to corrosion (potential difference between 2 different metals), and standard lack of lubrication, it can get really stuck. The missing thread is not your biggest problem, once apart you can drill a hole in the pin and thread this, I sometimes weld some thread back to the pin. It doesn't need to hold eny excessive forces.

But your problem is how to get the pin out of the caliper. I have sometimes beaten it out, whil supporting the aluminum part on a partially opened (big) vise grip. This method will leave some marks on the caliper, but it's still usable. Sometimes I even had to heat it with a paintstripper to the point that I needed gloves to hold it and use the biggest hammer I have. Adding some oil wherever possible hepls a bit, but some O-rings (probably for preventing water to enter) prevent oil to penetrate everywhere. But it's the absence of any oil or grease that got it stuck in the first place.

Maybe if you're Lucky, heating will get it out, but I think some force is necessary. Try not to destroy your part. Once it works, this is the better brake to have.

[juhl-drengen]

I have tried to hold it on a grip at beat it out while lubricating it (marks ouch..)

But it did not move a MM.. so maybe i'll make on of my buddy's try a wrestle with it he has acces to gas/oxygen!

I thought i would be a better brake when i bought it! its actually gonna go on a RD80MX front fork on a FS1 with RD80LC2 Wheels, the brake disc of the rd80lc has a 20mm bigger diameter than the mx or fs1, so i had to find a usefull caliper, i stumpled upon this, in denmark we stopped getting the 4g fs1 in 1979, and our 79's is practically over saved 78's.. so the Square caliber, "rd" like seats and that never came to denmark, because of the law that killed the 4g we first got a fs1 Again in 1988 with 2 gears, a weight of 60kg, plastic fenders and a horrrible "comfort".. so parts from foreign 80's FS1's is a Little rare thing to find in denmark but thanks to no interest for the parts they are cheap and many times in good condition, i got this one for 1/10 what and ordinary 76-78 caliper would cost.. only fail on it is the damaged thread on the pin..


BTW i dont need an explanation for what corrosion is, in my daily life i'm a "surface painter" (dont know correct English term..) so im educated in corrosion, painting, blasting and so on