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Last Winter the front brakes on the Pan (ST1100) started binding, so I gave then a quick overhaul. All was good for a while, but one of the pots started binding again, not badly but enough to annoy.
What made it worse is that the garage is on a slight slope, so any friction when pushing back in there is very noticeable.

It was time to the job properly. The cheapest place for genuine Honda spares is David Silver Spares, so two brake caliper seal kits were duly ordered.
I had some trepidation about doing the overhaul, as I had visions of a number of issues involving the seals and the bedding of them. As it was, I needn’t have worried as it went really smoothly.

I did not intend going through the whole process, but just cover a few tips, but have decided that I will highlight all the steps:

  • Before removing the callipers, remove the pads, push pistons out disconnect the hydraulic hose.
  • Squeeze the brake lever to push the pistons as far out as possible.  Do not let them pop out.
  • If only one of the pair comes out, use a bit of wood to block it coming all the way out, the other one will then push out.
  • Now use a pair of mole-grips to lightly clamp the hydraulic house.  Do not clamp too tightly or you will damage the hose.
  • Undo the bolt holding the hose to the calliper.  Watch out for the metal washers, and ensure no fluid gets on the paintwork.
  • Remove the calliper and hold it upside down to let the hydraulic fluid pour out.
  • Use a pair of mole grips to gentle pull the pistons out.  Only grip the very outer edge of the piston and try not to scratch it.
  • Gently pry out the old seals.
  • Wipe out the barrels.
  • There is a good chance that there will be corrosion of the aluminium so the next couple of steps relate to that.
  • Gently heat the grooves with a blow torch.  Do not try to melt them, and the calliper will get hot so beware fingers.  This will turn the deposits to a powder that will come off more easily 🙂
  • You can then carefully dislodge the deposits with a small flat head screwdriver, or you could use a Dremel with a “chimney sweeps” brush (see photo above).
  • Thoroughly wipe out the groves and barrels again.
  • Lightly coat the new seals with brake fluid, I use silicone lubricant, and bed them in to the grooves.
  • Clean off any deposits from the pistons.   Do not scratch them.
  • Lightly coat the pistons in hydraulic fluid, or silicone lubricant, and gently slide them back into the cylinders.  Do not force it or you may damage the seals.
  • Refits the brake pads.  Make sure you put some copper grease on the faces to stop the brakes squeaking.
  • Refit the callipers
  • Refit the hydraulic hose
  • Bleed the brakes.  Do not squeeze the brake lever rapidly, as that will create tiny air bubbles in the fluid making it harder to bleed all the air out.  Make sure you top the reservoir up as you pump the fluid back into the callipers.
  • Adjust the position of the lever, as required.
  • I would recommend you bleed the brakes again after a few miles, and the fluid has been left to stand overnight.

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