MK II Front Caliper Rebuild?
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cliffa
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I don't use air as it can be a bit risky. Here's how I do it. Once the cap is off, push the outer piston all the way in and you should be able to pick the seal out. The outer piston should come out easily then. Next heat the caliper( quite hot), spray some lube around the inner piston, then holding it with an oven glove or similar smack it down on a piece of wood laid on a solid floor and the inner piston should start to move.
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The inner piston?
After removing the outer piston as cliffa described and also in the link below:
Rebuild a Norton Commando Disc Brake Caliper - Motorcycle Classics
Rebuild and update Norton Commando disc brake calipers.
www.motorcycleclassics.com
To remove the inner piston with compressed air, insert a rag into the outer piston bore then block the outer piston to bleed nipple drilling with a pointed 'plug' (point of a pencil or similar), apply low pressure (40-60 psi should be enough) compressed air to the bleed nipple drilling.
When replacing the inner piston, press it in only as far as it needs to go to insert the brake pad as the piston can block off its own feed drilling if pressed all the way into the caliper.
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OK, I went after it before anyone replied.
Here's what worked for me.
1) I applied air pressure to the inlet port which pushed the outboard piston inwards exposing the seal in the caliper.
2) After removing the plug and picking out the seal I was able to remove the outboard piston.
3) I applied air to the bleed port which pushed the inboard piston out.
4) After removing the inboard piston I was able to pick out the inboard seal.
Here's what worked for me.
1) I applied air pressure to the inlet port which pushed the outboard piston inwards exposing the seal in the caliper.
2) After removing the plug and picking out the seal I was able to remove the outboard piston.
3) I applied air to the bleed port which pushed the inboard piston out.
4) After removing the inboard piston I was able to pick out the inboard seal.
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The caliper was in good nick and did not offer any resistance. I applied a small amount of Never-Seize on the threads when I replaced the plug.
Tornado
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I recall I got both the pistons out just by using the MC still with fluid in. I think I used a bit of alu flat bar to clamp the outer piston still, making the inner one move out the most. Then removed cap, pushed out out, wiggled inner out after.
I was replacing pistons with new SS so did not care if grips etc were to be needed.
I was replacing pistons with new SS so did not care if grips etc were to be needed.
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Here is the caliper rebuilt and polished.
Waiting on a 25" braided SS hose from Walridge Motors. I ordered a 23" by mistake.
Also I am installing a new Andover Norton 13mm MC with the mirror mount.
Since everything is new and/or flushed, I am opting for DOT 5 silicone brake fluid.
Waiting on a 25" braided SS hose from Walridge Motors. I ordered a 23" by mistake.
Also I am installing a new Andover Norton 13mm MC with the mirror mount.
Since everything is new and/or flushed, I am opting for DOT 5 silicone brake fluid.
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None of my business, and maybe you have covered this before, but have you confirmed that all of your new seals are compatible with DOT 5? I have had DOT 3 compatible seals "shrink" when exposed to silicone brake fluid.
I would just hate for you to have a nasty "surprise"....
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There are numerous posts on here by those running DOT 5 in the Norton Lockheed system. The main caution is to not try to introduce DOT 5 into a system that may have non-silicone based fluids present.
The other caution is about silicone based brake fluid being non hygroscopic which sounds like a plus to me.
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Recommended Brake Fluid MK II Front Brake?
Derek, brake fluid replacement is more of a Calander, rather than mileage issue. Fluid life varies depending upon how humid your local climate is. Buy one of the fluid testing pens on Amazon and you won't have to worry, plus you won't have to flush it more often than really needed. You can use...
www.accessnorton.com
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Fair enough - I am just an anal retentive braking system engineer with a history of bad career experiences with brake fluids - too much to go into here. I am actually a big fan of air brakes - LOLRecommended Brake Fluid MK II Front Brake?
Derek, brake fluid replacement is more of a Calander, rather than mileage issue. Fluid life varies depending upon how humid your local climate is. Buy one of the fluid testing pens on Amazon and you won't have to worry, plus you won't have to flush it more often than really needed. You can use...
My line of questioning is completely altruistic
Tornado
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I know in the classic mini forum, there are lots of negative experiences with DOT5. Though another advantage over glycol based is no risk to paint damage, concerns continue that it can foam more easily than DOT4/3. Leading to sudden pedal pressure loss.
Tornado
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While no water absorption in principle is good, if any creeps in over time, past seals, fittings or the MC cap, then it doesn't mix and accumulates at a low spot in the system, leading to corrosion.
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Yes, water absorption principle is similar to detergent oil - gather up the nastiness and carry it in suspension so that it does not collect anywhere. Flushes out when you change it.
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Not Dot 5, as Dot 5 is silicone based the water never mixes but instead moves to the lowest point and accumulates there in one ball of water, if there is any steel nearby that then rusts. Dot 3 4 and 5.1 absorb water so that is mixed evenly through the fluid lowering the boiling point.
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No, I was referring to DOT 3/4/5.1 - sorry, should have clarified - edited post for clarity
Carry On.
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The same could be said for ethanol gas compared to non ethanol gas.
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