Cast iron brake caliper - can they be welded?
Discussion
Hi, picked up a very cheap "for spares" set of Princess 4 pots. Seller did say that one was leaking badly through the body. I've stripped them down and found that someone has ground the outside off to such a point that the one of the circular rebates for the jointing O ring has been exposed and the O ring is then being forced out of the 1.5mm gap by the brake pressure. Is it possible to run a seam weld on cast iron just to "butter" over the tiny void? All that's needed is a little metal to hold back the O ring. Alternatively I could try and get a thin section of stainless tube cut and fitted as a liner which would also retain the O ring. Any thoughts about from bin it? Cheers.
Yes you could, is the short answer... and if it was the last caliper on the planet it might be worth doing, but if you had a crash and the caliper was found to be at the root of it you'd be losing more than your NCD.
Cast iron is bloody 'orrible stuff to get a decent weld on; luckily they will have been cast in the days when British metals were made of what they were supposed to be so with lots of prep and the correct filler rod a good welder could probably salvage it... given how cheaply you can buy the AP 4-piston calipers, is it worth the chew?
Cast iron is bloody 'orrible stuff to get a decent weld on; luckily they will have been cast in the days when British metals were made of what they were supposed to be so with lots of prep and the correct filler rod a good welder could probably salvage it... given how cheaply you can buy the AP 4-piston calipers, is it worth the chew?
Are they really cast iron - as in high carbon? I would have thought the brittleness of cast iron would be far too dodgy for calipers full stop. i've whacked calipers with a hammer before and they don't have that cast iron "ping". But I stand to be corrected.
If they are steel castings then it should be a piece of piss.
If they are steel castings then it should be a piece of piss.
Adam, steel castings they are indeed. The welder in our workshop checked them out and likewise pronounced the repair a piss of p**s. Took him 10 minutes with TIG and carbon steel filler wire to build up the repair and tidy it up. All looks good. I'll rebuild and then get them pressure tested, also in our workshop. I knew this new job was a good idea!!!
KKson said:
Adam, steel castings they are indeed. The welder in our workshop checked them out and likewise pronounced the repair a piss of p**s. Took him 10 minutes with TIG and carbon steel filler wire to build up the repair and tidy it up. All looks good. I'll rebuild and then get them pressure tested, also in our workshop. I knew this new job was a good idea!!!
did you pre heat the caliper before welding? or you will get an heat effected zone, so maybe one day when the caliper gets hot and you are braking hard,it could crack. I wish you luck though 
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