caliper strip down

Persevere with the heating up of caliper using the expansion differentials of alloy and steel to break the seal. I put mine in the oven for 15 minutesset at 200 degreesthen securefirmly in a vice and apply decent peg spanner. Has never failed to shift end cap. Made my own peg spanner in the end- as you rightly saythe ones I'veboughtof various designs have never been up to it - cutting and shaping a piece ofscrap steel to form pegs which fit into a large ring spanner , with a length of GI pipe on the spanner for good measureto provide serious force.

As an aside , eventually I gave up on the original Norton-Lockheed caliper and discon front brakes of both my MK1A and MK3 850'sand fitted Norvil and RGM upgrades which have both produced better front stoppers.

Clean, soak in plus gas for a few days. clean off wrap in oven foil then in the oven on full for half hour. Wear gloves to handle.

You need patience if it has not been stripped before it has over 40 years to corrode in place. Steel and Ally more or less weld them selves together. When heated holes expand and Ally expands more than Steel.

The other thing is to put a clamp loosely around the caliper and end plate so that when you tun it the tool cannot lift and bend the pegs. You only need it to move enough to break the seal. Then remove clamp and apply more plus gas and let it penetrate or the thread may pick up again.

My exhaust C spanner has 2 holes near the end of the handle appropriately spaced and containing 2 allen headed bolts to fit the caliper plug; so 2 tools in one,easy to grip & a bit of weight.

I can't take the credit, the caliper tool was out of stack at the time I bought my Commando (20 years ago) & my late father knocked this up.

Mike

Now you will have all the fun of trying to get the pistons out of the calliper ...

I gave up and bought an AP caliper and mounting kit from Norvil for my 750's front brake. But what do people do about the MkIII rear brake?

Luckily original Norton-Lockheed set up onmy MK 3 rear brakeis still OK following a new master cylinder and refurbed caliper a while ago. Not sure what I'll do if and when pistons show signs of sticking but I've got four spare old calipers in variousconditions to play with.

RGM or Norvil , can't remember which , now do caliper pistons with a tapped central hole into which you screw a suitable bolt for drawing out the inner piston.

The AP caliper upgrade kits for front brakes from RGM and Norvil are excellent. Fittedthese on both my 850's retaining original refurbedNorton master cylinder in both cases.

I removed my old pistons by using a grease gun and pumping them full of grease. I had previously tried all other methods like an air line but they leaked to much. The grease leaked past the pistons but they eventually came out. Only to disclose that the calipers were in such a bad state I did not risk using them.