Caliper inner piston removal - simple method

cliffa

cliffa

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A friend of mine asked me to remove the inner piston from his standard Norton Lockheed caliper. (He had already removed the cap and outer piston and dumped them) My normal practice is to heat the caliper up until it's really hot then holding it with a suede glove smack it down onto a piece of wood on a concrete floor. This has never failed me in the past, but this one just would not budge ( I bruised my hand by repeatedly trying). I don't have an airline and am not too keen on the greasegun method, but as the caliper was incomplete it wouldn't help anyway. So I resorted to Google, and found this video:



Using a hex Allen key is not really feasible on the Norton caliper, so instead I used a 1/2" drive extension and T bar. I heated the whole caliper, put it in the vice (not a workmate ;)) , then I put about 6 short 1/4" drive sockets into the piston and jiggled the square drive into the centre. I turned the T bar, and could not believe that the sockets immediately gripped the piston, and it started to turn. Continuing to turn it I started to to pull upwards and out came the piston! I was amazed!! From dropping the sockets into the piston and it coming out was about 45 seconds.

Strangely the piston was not really that bad, and the groove for the inner seal was not full of calcium which normally causes the seal to grip so tight.

Now on to the next challenge, getting the broken bleed nipple out which has a screw extractor snapped inside it. Any tips? :(
 
I always remove inner stuck pistons with air, but also have no air line. I use a foot pump or battery-operated tire inflator. Only takes a few seconds and pop. (Mind your fingers though)..
 
As per Bilko, block the hole that runs between the caliper halfs, a small piece of inner tube and a C clamp does it, and then pump oil using an oil gun and the piston is moved out. The video shows a good solution but piss poor application 😂 , those plastic clamps on the workmate are there to be used on round or odd shaped objects but vice is the real solution.

EDM will get rid of the screw extractor, then drill the nipple with a drill sized at or just below the thread root dimension, use a tap to clean the threads of the nipple remains and fit a stainless nipple with copper grease on the thread.
 
cliffa said:
A friend of mine asked me to remove the inner piston from his standard Norton Lockheed caliper. (He had already removed the cap and outer piston and dumped them) My normal practice is to heat the caliper up until it's really hot then holding it with a suede glove smack it down onto a piece of wood on a concrete floor. This has never failed me in the past, but this one just would not budge ( I bruised my hand by repeatedly trying). I don't have an airline and am not too keen on the greasegun method, but as the caliper was incomplete it wouldn't help anyway. So I resorted to Google, and found this video:



Using a hex Allen key is not really feasible on the Norton caliper, so instead I used a 1/2" drive extension and T bar. I heated the whole caliper, put it in the vice (not a workmate ;)) , then I put about 6 short 1/4" drive sockets into the piston and jiggled the square drive into the centre. I turned the T bar, and could not believe that the sockets immediately gripped the piston, and it started to turn. Continuing to turn it I started to to pull upwards and out came the piston! I was amazed!! From dropping the sockets into the piston and it coming out was about 45 seconds.

Strangely the piston was not really that bad, and the groove for the inner seal was not full of calcium which normally causes the seal to grip so tight.

Now on to the next challenge, getting the broken bleed nipple out which has a screw extractor snapped inside it. Any tips? :(
Click to expand...

Same principle the sprag drive works on. 💡

Thanks for sharing. 🍻
 
cliffa said:
A friend of mine asked me to remove the inner piston from his standard Norton Lockheed caliper. (He had already removed the cap and outer piston and dumped them) My normal practice is to heat the caliper up until it's really hot then holding it with a suede glove smack it down onto a piece of wood on a concrete floor. This has never failed me in the past, but this one just would not budge ( I bruised my hand by repeatedly trying). I don't have an airline and am not too keen on the greasegun method, but as the caliper was incomplete it wouldn't help anyway. So I resorted to Google, and found this video:



Using a hex Allen key is not really feasible on the Norton caliper, so instead I used a 1/2" drive extension and T bar. I heated the whole caliper, put it in the vice (not a workmate ;)) , then I put about 6 short 1/4" drive sockets into the piston and jiggled the square drive into the centre. I turned the T bar, and could not believe that the sockets immediately gripped the piston, and it started to turn. Continuing to turn it I started to to pull upwards and out came the piston! I was amazed!! From dropping the sockets into the piston and it coming out was about 45 seconds.

Strangely the piston was not really that bad, and the groove for the inner seal was not full of calcium which normally causes the seal to grip so tight.

Now on to the next challenge, getting the broken bleed nipple out which has a screw extractor snapped inside it. Any tips? :(
Click to expand...

Ive done this in the past (removing bleed screws with broken extractors in them) by careful use of a dremel or similar with a diamond coated bit. The diamond slowly grinds away whats left of the extractor. once its out the way the screw can be opened out till the thread is revealed.
Patience is required and a steady hand also working with a vision visor or similar to help seeing what you are doing. The rotary tool and diamond bits i got cheap from Lidl (a discount supermarket over here in the UK)
 
dobba99 said:
Ive done this in the past (removing bleed screws with broken extractors in them) by careful use of a dremel or similar with a diamond coated bit. The diamond slowly grinds away whats left of the extractor. once its out the way the screw can be opened out till the thread is revealed.
Patience is required and a steady hand also working with a vision visor or similar to help seeing what you are doing. The rotary tool and diamond bits i got cheap from Lidl (a discount supermarket over here in the UK)
Click to expand...
Coincidentally that's exactly what I was planning on trying - great minds and all that! I have to use a magnifying visor (Loupe) for lots of stuff these days, in fact it's probably my most used tool 👓o_O

1697201606403.png
 
cliffa said:
A friend of mine asked me to remove the inner piston from his standard Norton Lockheed caliper. (He had already removed the cap and outer piston and dumped them) My normal practice is to heat the caliper up until it's really hot then holding it with a suede glove smack it down onto a piece of wood on a concrete floor. This has never failed me in the past, but this one just would not budge ( I bruised my hand by repeatedly trying). I don't have an airline and am not too keen on the greasegun method, but as the caliper was incomplete it wouldn't help anyway. So I resorted to Google, and found this video:



Using a hex Allen key is not really feasible on the Norton caliper, so instead I used a 1/2" drive extension and T bar. I heated the whole caliper, put it in the vice (not a workmate ;)) , then I put about 6 short 1/4" drive sockets into the piston and jiggled the square drive into the centre. I turned the T bar, and could not believe that the sockets immediately gripped the piston, and it started to turn. Continuing to turn it I started to to pull upwards and out came the piston! I was amazed!! From dropping the sockets into the piston and it coming out was about 45 seconds.

Strangely the piston was not really that bad, and the groove for the inner seal was not full of calcium which normally causes the seal to grip so tight.

Now on to the next challenge, getting the broken bleed nipple out which has a screw extractor snapped inside it. Any tips? :(
Click to expand...
 
The best way bar none is to use the brake master cylinder to pump it out . Do this after you pull the pads and have the caliper hanging on the brake line. The outer piston will come out if you heat up the caliper with a 1600 watt hair dryer.....
 
I will be rebuilding my caliper this winter for the first time. Your comments appreciated

Do you pull pads, then somehow hold right side pad from moving to the left, then pump to force left side piston to come out as far as it will?
Dennis
 
FastFreddy said:
The best way bar none is to use the brake master cylinder to pump it out . Do this after you pull the pads and have the caliper hanging on the brake line. The outer piston will come out if you heat up the caliper with a 1600 watt hair dryer.....
Click to expand...
I'v used this method on bikes and automobiles, if two piston caliper pump the brakes and usually one piston will move out, push it back in a bit and clamp it down and pump the brake pedal / lever to get the stuck one out.
 
An inexpensive method I have used to leverage pucks out of calipers is to use a box wrench:

Caliper inner piston removal - simple method
 
Inner piston came out easy the other day using air blow gun carefully at low pressure. New stainless piston didn’t want to go into the inner position until I stopped panicking and got the heat gun on the caliper. ’Twas cold out in the shed this morning.
 

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