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[tommyardin]

[quote author=tommyardin link=topic=23494.msg271138#msg271138 date=1510529829][size=0.7em]
Could also be the seals in the caliper doing that and causing that same feeling, If the caliper seals are sticking I would have thought that they would hinder the front wheel from spinning, apply the brakes a few times stationary letting the lever out slowly and try spinning the front wheel, if it spins fine then your guess is probably a good one.
Might be worth checking the brake lever pivot pin to make sure that is free and the pin hole in the handle bar mount is not worn oval as that can cause issues as well.

But as you say it is very low mileage and if there is a lot of rust around the bleed screw then the caliper piston seals are worth checking, so its worth a check to see if they are causing the judder. As the bike is stationary it is not a rolling issue for example warped discs, or a buckled wheel, both of which can cause discs to snag. 
good luck. [/size]

Hmmmm, I was hoping you wouldn't say that! Good point, so I did your, apply the brakes / lever out slowly / spinning the front wheel, [size=1em]and.... well... the pads are definitely letting go of the discs, in that there is no heavy binding, or pressure there, but they are still touching, and quickly stop the wheel from spinning freely. In comparison, the rear lets go, and the wheel spins freely. So from that I think that the front caliper seals have aged, lost their flexibility, and, well, probably need changing, darn it! So as well as probably changing the Master Cylinder Seals, I am going to have to change the Front Caliper Seals as well ! I will try and take a video...[/size]
[size=1em]Cheers, Mitch...[/size]
[/quote]


Do check the lever pivot pin/BOLT as some have rightly called it before embarking on the more time consuming jobs.



[size=1em]As others have mentioned it is worth popping the pads out (Remember the way they came out and locate them in the same position when they go back in) remove the caliper bolts but don't remove the brake line banjo union get a piece of approximately  15mm to 20mm thick plywood about 50mm wide, length not really important say 250 mm long. Place the ply between the four pistons and slowly pull the brake lever so that the four pistons grip the wood (The ply stops the pistons popping right out) with the piston pushed out to the ply give them a good clean with brake cleaner (Some say you can submerge the whole caliper in a bucket of hot soapy water) and scrub them with a old tooth brush (Or the wife's, but not your own) take you time and thoroughly clean the pistons dry them off and smear them with red rubber grease, don't use ordinary mineral grease as it shags the seals.[/size]
[size=1em]Once greased undo the bleed screws on that caliper and firmly twist the piece of ply forcing the pistons back into the caliper body. [/size]
[size=1.35em]Make sure you fit the cleaned caliper back on fork leg/disc with pads back in before you start on the other one, its easy to forget and get carried away and the push the pistons right out of the one you just cleaned, so it's important to refit the first before commencing.[/size]

[size=1em]Now if that doesn't solve the juddering you will have very clean and serviced calipers, then look at the master cylinder.[/size]
[size=1em]Good luck [/size]
[size=1em]keep us informed how you get on. [/size] :thumbup