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Re: best way to seperate brake calipers?

Posted: 20 May 2012, 13:41
by fallenmikethebike
fishtail wrote:thanks! actually the chain actually does look a little bit gnarly... ( so once I fix up the brakes and put on the DEP downpipes - maybe I will get a new one.. )

to be honest I climbed some pretty steep stuff today.. seems I do prefer 1st - and being able to lift the front came in handy a few times ...


( googling how to tell if your dirtbike chain is fecked right now )
ideally. you would measure it over a certain number of links, or compare to a new chain.
In practise, if you can pull more than 10mm at the extreme rear of the chain over the back sprocket, it's replacement time.IMO.
Mike

Re: best way to seperate brake calipers?

Posted: 20 May 2012, 15:30
by fishtail
thanx mike!! - didnt find such a direct google answer... :)

Re: best way to seperate brake calipers?

Posted: 21 May 2012, 07:52
by fishtail
well finally went in.,,

here are the pistons..

Image

are they servicable? - I tried wiping them with a soft cloth and sprayed em with cleaner ( sever times ) the surfaces dont look particularly smooth





the calipers were filthy on the inside - I spent 30 mins with soft cloth and soft tooth brush.. - think some of the grroves where the seals go have a bit of corrosion on them,,


Image


just cant get them cleaner ?


wondering if they will qualify as being "better than before" if I just say sod it and put back together....


oh yeah and then there's the master cyclinder.... the boot seemed to be jammed in - eventually it came out - but not in one piece

and the botton I needed to grab with pliers - it came out and there's a metal ring inside the rubber that had corroded to crap and back,..

but this happened on the way...,, :shock:


Image

oh well looks like I will be getting a new master cyclinder after all --

should I

a) just put calipers back together with new seals and see if any better?

b) grab some new pistons first?

c) scrap the lot and get a shiny new one to match my new (2nd hand ) DEP? :D

Re: best way to seperate brake calipers?

Posted: 21 May 2012, 08:46
by voodookid37
for seal grooves.....i leave a drip of fluid in the groove gently scrape the offending cack with a dental pick.then wipe out and give them a quick whizz with a soft nylon brush in the dremel.........works a treat every time........ :P

Re: best way to seperate brake calipers?

Posted: 21 May 2012, 13:04
by fishtail
well I got the electric toothbrush on it cos I dont have a dremmel... ( maybe I can get a head for my electric screwdriver for next time! )

seems better - and the brake fluid did better than the "brake cleaner spray" I had brought.


got mastercyclinder ( 2nd hand) from an XR400 - the guy in the shop put in new seals for it... well he offered and I thought why not!


thing is I'm pumping the lever and the fluid level doesnt seem to be going down anymore !!! ( not like 2 weeks ago when I put the new brake hose on seem to remember that went down quicker???)

some fluid has started to appear at the bleed screw - but it really does seem to have stopped pumping fluid thru - cos after 10 mins of pumping the level hadnt shifted in the master cyclinder... and the fluid sort of lurches into the tube on brake "on" stroke

and gets sucked back in on "brake release" stroke.......


( caliper was on the other handle bar - slightly raised above the master cyclinder ..

anyways its got dark here - and my garage is the side of the street and I dont have any power there - so if anyone has some suggestions I'd be grateful!

hopefully can get this working and my exhaust re-packed tomorrow!

Re: best way to seperate brake calipers?

Posted: 21 May 2012, 14:33
by garyd
Yep heres a suggestion to the power issue ............connect up to the street lights!! as for the bleeding of brakes ,have the caliper held up higher than the master cylinder ,air will rise,and leave brake lever cable tied back to bars over night

Re: best way to seperate brake calipers?

Posted: 21 May 2012, 18:00
by fallenmikethebike
Reverse bleed, from the nipple up to the master.
You will need a large syringe and some clear tube.
Mike

Re: best way to seperate brake calipers?

Posted: 22 May 2012, 02:59
by fishtail
cheers mike

found this on your tip

http://www.youtube.com/watch?v=lBk00597EyE

Re: best way to seperate brake calipers?

Posted: 22 May 2012, 14:53
by fishtail
and after all the palava

- new caliper seals - new master cylinder seals...

reverse bleed - ( at least I got that kit together for next time now! :D )

the brakes are more or less the same - :oops: ( biggest improvement was adding the braided hose,,,, )

gonna get a new disc next cos that does look a bit worn too...