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Servicing Front Hydraulic Disc Brake
Posted: Mon Jul 13, 2009 10:32 pm
by storkfoot
One of my two ScootRS set ups binds a bit_____if you prop the front wheel up and try and spin it, it'll only go about 1 revolution, if that. The disc doesn't look wharped, and the pads aren't worn out. I'm guessing that the pistons are sticking in the calipers
Assuming the pads are not worn out, what service items do I need to do this____just an O ring and some grease, oh, and some new brake fluid?
Does anyone has a link to a DIY guide of how best to do this ?
Re: Servicing Front Hydraulic Disc Brake
Posted: Tue Jul 14, 2009 7:29 am
by scootRS.com
Check the lever isn't on at a tiny bit; if so, take 2mm off the part that presses in the MC button dealie.
You can try to give the pistons a wiggle with some oil around the outside edge of them if sticky.
Re: Servicing Front Hydraulic Disc Brake
Posted: Tue Jul 14, 2009 8:02 am
by eibargum
Had trouble with mine last friday, it locked on solid when i applied it, would only release if i let some fluid out, turned out to be crap in the pipe which would,t let the fluid back, you could have the same problem but to a lesser extent.
Re: Servicing Front Hydraulic Disc Brake
Posted: Tue Jul 14, 2009 8:15 am
by storkfoot
This scoot has been off the road for over a year but, it memory serves me right, it started catching after I had to partially strip it to change the speedo drive. It's a Nissin caliper. I used a dremel on the lever when I set it up originally so I'm sure that's not it.
Re: Servicing Front Hydraulic Disc Brake
Posted: Tue Jul 14, 2009 4:17 pm
by eibargum
Its not a hard job to strip and repair, you can leave your brake hose on if need be but you have to take the wheel off the hub to remove the caliper to get at the pistons.
Re: Servicing Front Hydraulic Disc Brake
Posted: Tue Jul 14, 2009 5:03 pm
by scootRS.com
Try what I said first, then maybe clean the line out and rebleed if needed. Could be a spot of rust or something.
Re: Servicing Front Hydraulic Disc Brake
Posted: Wed Jul 15, 2009 1:39 am
by corrado
scootRS.com wrote:Check the lever isn't on at a tiny bit; if so, take 2mm off the part that presses in the MC button dealie.
That's definitely something that needs doing if you replace the lever with a polished one.
Re: Servicing Front Hydraulic Disc Brake
Posted: Mon Jul 20, 2009 11:54 pm
by storkfoot
OK, stripped calipers. The pistons were sticking very slightly so sorted that. At the same time I replaced the seals as a couple were a bit feathered at the edges. I've put it all back together and whilst it is very slightly better, I still can't spin the wheel freely beyond 1 revolution.
I've even got the dremel on the lever again just to make sure, but it looks like I might just have to live with it unless anyone's got any other ideas?
PS. I changed the DOT4 again but forgot to clean the hose. Could this really be the problem?
Re: Servicing Front Hydraulic Disc Brake
Posted: Mon Jul 20, 2009 11:58 pm
by RICSPEED
storkfoot wrote:OK, stripped calipers. The pistons were sticking very slightly so sorted that. At the same time I replaced the seals as a couple were a bit feathered at the edges. I've put it all back together and whilst it is very slightly better, I still can't spin the wheel freely beyond 1 revolution.
I've even got the dremel on the lever again just to make sure, but it looks like I might just have to live with it unless anyone's got any other ideas?
PS. I changed the DOT4 again but forgot to clean the hose. Could this really be the problem?
possible something is slightly out of line but i wouldn't let it bother you

Re: Servicing Front Hydraulic Disc Brake
Posted: Tue Jul 21, 2009 12:31 am
by corrado
I've lost the link now but seem to recall there being some good info on Lloydy's lambretta site.
Ah, found it........
http://www.lloydy.org/ click on 'how to' and follow the disc brake links.