rebuilding blue spot calipers

[ogri48]

I fitted a new front bt016 to the yam, and while I had the wheel out finally remembered to fit a decent 90 degree valve, As its finished winter commuting duties now, im changing or sorting corroded bolts etc as I go. the front axle pinch bolt was a simple swap for a stainless one, whilst I cleaned up the caliper bolts with a wire wheel, then done the old heat/oil thingy to rustproof and black them. Cleaning up the caliper, I found three winters have really taken their toll, despite regular maintenavce. One of the pistons was so tight, the pin the pads slide on was actually bent. I know from experience that no amount f brake cleaner/toothbrushing is gonna sort the problem; corrosion in the piston seal groove is pushing the buggers out, and they need stripping, cleaning and new seals.
So...ive never done blue spots before. Im assuming I gotta get a tool to unscrew the plug and the pistons pull out of the hole. what im not sure of is how this affects the piston seals when you re-assemble..ie normally you have the lip to the inside of the caliper..but how do I push the pistons back in from behind without damaging them if thats the case? Also, is Fowlers and genuine seals the way forward, or are the fleabay ones ok? all help much appreciated fellers....

[Dudeofrude]

Although the blue spot tool can be handy I've never felt the need to remove them. I've rebuilt the older blue spots on a thundercat about 6 times without removing the spot at all. Just popped them out the middle the old fashioned way

[ogri48]

ah, interesting, ta mate! ive got a piston tool, i'll do that. Just got a seal kit cheap enough of ebay, Kyoto, original fitment so it says

[Dudeofrude]

The only thing to check with the copy seals is that they are perfect with no deformation/holes/extra lips.
First cheap pair I bought were terrible, had clearly been made from a poor mold but second ones were fine. I'm sure Kyoto is a real brand so should be fine

[ogri48]

ps. note the roughly cut front paddock stand. For about ten years ive persevered with a stand that lifts a little too high for my uprated front and rear suspension settings, meaning i have to take the bloody rear wheel out first, but the other day I thought "why dont I just drill holes an inch down, cut an inch off the top and re site the cradles".
so simple and works perfectly.
if only I thought of it ten years ago.....  

[ogri48]

sixteen quid for two complete sets bud, gotta be worth a punt. id love to stick to oe for stuff like this but running three bikes makes it a no no 

[Mustang]

I did my blue spots the other week, didn’t need to remove the blue bits, reused the seals except when I lost a dust seal, found one off another bike kit fitted, brakes free moving now.

[ogri48]

 

[PieEater]

Too late now but when I did mine I was advised to get the seals from WeMoto. As others have said you don't need to touch the blue spot covers just use some caliper pliers to ease the pistons out from the inside.