due to knee problems I couldn't ride my '75 Norton for a couple of years. Now I 've got a new platinum knee, I started her up again and went around the block. The front calipers are stuck, so I removed the brake assembly. Since there is only access to 1 side, I was able to remove 1 caliper but the "blind" caliper does not want to move at all. I tried with air pressure, but it is stubborn. Any trick on how to remove the "blind" caliper so I can clean and replace seal?
disc brake calliper
- Thread starter dezwartj
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Onder
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Well if is really stubborn, take it off, wash it out, heat it to 275 in the oven
and then hit it with 100 pounds of air.
Alloy body will swell faster and larger than the steel piston. It may take quite
nearly an hour to get the piece to absorb the heat. Check it with your handy
infrared thermometer.
Remember they have rubber seals inside so expect some disgusting smoke.
and then hit it with 100 pounds of air.
Alloy body will swell faster and larger than the steel piston. It may take quite
nearly an hour to get the piece to absorb the heat. Check it with your handy
infrared thermometer.
Remember they have rubber seals inside so expect some disgusting smoke.
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I had the same problem. I warmed the caliper up with my gas torch but it still wouldn't come out.
Just as I sat the caliper on the bench to think it through my 6 year old raced through the shed with a stick in his hand. He collected the caliper and it shot off the bench onto the floor. Pop! Out comes the piston. :shock:
Heat and a sharp rap should do it. Replace with RGM piston that has threaded boss for removal.
Just as I sat the caliper on the bench to think it through my 6 year old raced through the shed with a stick in his hand. He collected the caliper and it shot off the bench onto the floor. Pop! Out comes the piston. :shock:
Heat and a sharp rap should do it. Replace with RGM piston that has threaded boss for removal.
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Penetrating fluid soaking ,heated by boiling water in a pot ,big leather gloves and a whack on soft wood worked for me. The new pistons that went in were stainless Steel. The big O-rings that seal the pistons have to go in facing the correct direction. They are tapered square section . The raised edge goes towards the back of the bore. Cleanliness important here. :wink:
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Peter Lovell of Lovell Racing Developments in Birmingham has a special tool to use on customers similar problematic callipers. Should that not work he reverts to drilling a hole and thumping (with skill) a lump of steel rod to remove the piston and then either welds up the hole or if asked nicely will tap it so a screw can be used to seal it allowing for future use.
Personally these days I would adopt something that was once common in the World before we in the UKand elsewhere killed off Engineering and industry and everyone became bloody accountants or thieving bankers ...it was called preventative maintenance in my young days and involved assembling the piston into the calliper with a smear of Copperslip applied and repeating the exercise every once in a while to ensure the problem never occured. Similar preventative maintenance was to follow the Renold chain instructions and remove clean and re-grease ones rear chain after every 1,000 miles of use...or at a lower mileage in bad weather conditions. This of course was long before the advent of X and O ring chain but even that should be regularly lubricated to make life easier on the rollers as they come into contact with sprockets. Mind you if the number of Japanese bikes i hear passing me with noisy rear chains is any indication lubrication is never applied. Remind me how much a new rear chain and sprockets cost these days when with just a little effort the life of both could be considerably increased although I suspect correct chain tension would help even more.
If only I had applied a bit of preventative maintenance in my youth......before I grew old and slightly wiser.
Question. How does heating things help if someone has fitted super dooper go faster hard anodised aluminium alloy weight saving pistons which will expand at the same rate as the aluminium alloy caliper? Tee hee thought I would throw that one in........
Personally these days I would adopt something that was once common in the World before we in the UKand elsewhere killed off Engineering and industry and everyone became bloody accountants or thieving bankers ...it was called preventative maintenance in my young days and involved assembling the piston into the calliper with a smear of Copperslip applied and repeating the exercise every once in a while to ensure the problem never occured. Similar preventative maintenance was to follow the Renold chain instructions and remove clean and re-grease ones rear chain after every 1,000 miles of use...or at a lower mileage in bad weather conditions. This of course was long before the advent of X and O ring chain but even that should be regularly lubricated to make life easier on the rollers as they come into contact with sprockets. Mind you if the number of Japanese bikes i hear passing me with noisy rear chains is any indication lubrication is never applied. Remind me how much a new rear chain and sprockets cost these days when with just a little effort the life of both could be considerably increased although I suspect correct chain tension would help even more.
If only I had applied a bit of preventative maintenance in my youth......before I grew old and slightly wiser.
Question. How does heating things help if someone has fitted super dooper go faster hard anodised aluminium alloy weight saving pistons which will expand at the same rate as the aluminium alloy caliper? Tee hee thought I would throw that one in........
Nater_Potater
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Hit the piston with "Freeze-It" http://www.alliedelec.com/chemtronics-e ... fgodp88GbQ or an equivalent coolant immediately prior to whacking the caliper. The sudden cooling of the relatively thin piston will cause it to pull away from the caliper body for a brief period of time.J. M. Leadbeater said:
Nathan
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So many operations on British bikes require judicious use of hot and/or cold. As for the seals , the manual is vague and subject to misinterpretations as to correct fitting. I believe the seals are square section outer where they drop into the home slot. The inner is tapered where it sits against the piston itself. Here the seal goes proud with raised edge facing towards the back of the bore. Hold it up to a light source to observe the seal taper.
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toppy said:
Correct. as with all automotive disc brakes in the 70's,80's and 90's.
Dereck
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