Advice please re front brake issue on Gen 1

[SkidT]

Ok guys,


At the risk of making myself look like a complete fool.............


Recently bought a Gen 1 Thou from another forum member (Kitty). The bike had been laid up for best part of a couple of years and therefore the front calipers were binding on. I had good pressure at the lever but they were just binding a little after release.


So, yesterday, I took them both off, took the pads out etc and gave them a bit of a clean up. Unfortunately, through a lack of foresight, whilst working on one caliper, I managed to pop out one of the pistons. I gave it a quick clean and managed to get it back in again without too much ado. I finished off by trying to bleed the brakes up again.


Unfortunately, I can now not get any lever pressure and am a bit stuck.


When trying to bleed it up, I was getting fluid coming through the bleed nipples but not with any great pressure. I can see no signs of leakage anywhere and I have been topping up the fluid reservoir. I've taken the offending caliper off again and had another good look but again, no signs of any fluid seepage from where I've replaced the piston.


I'm thinking that maybe the master cylinder seals may have gone, but cant undertand how that would have happened when all i've done is a quick clean / freeing up of the pistons / calipers. I also dont want to shell out on a new m/c seal kit if its not that causing the problem.


Have I missed something blindingly obvious here??? By the way, the bike has braided hoses so I dont think its those that have perished.


Any advice appreciated.


SkidT 

[Dave48]

Do you know the service history of the brakes? If not now is a good opportunity to overhaul the complete system with all new fluid,master cylinder overhaul kit, new caliper seals(piston& dust). Pref Yamaha-dearer than pattern but guaranteed to fit!(Bitter experience talking!).Inspect & clean callipers internally esp grooves for seals using proper brake cleaner. If pistons ok refit with red rubber brake grease to ease fitting past new seals. They must all move freely.
Re bleeding some use tube & jamjar-Ive been using a Mityvac for a few yesars & it soon gets the air out of system. Check your bleed nipples for corrosion/dirt. They should haverubber covers to prevent ingress ofdirt/water etc. Youll at least have brakes you know are 100%

[AyJay]

Don't panic! It's quite normal. I've rebuilt my brakes a number of times and I've found that bleeding the front callipers is a pain in the neck. It can take ages to get them up to pressure. Two tricks I've found are to wind the brake lever adjuster out so you get the maximum leverage and when it seems there are no bubbles coming out and you've still no pressure, take the callipers off and push all the pistons right back in again. Don't disconnect the lines or anything, just push the pistons in. I presume air gets trapped in the pistons.


Took me over an hour and a half once. Keep at it and it'll come good.

[SkidT]

Okay guys, thanks for the input. Kitty has pretty much a full service history and whilst she has been laid up for two years, she has only done 200 odd miles since her last dealer service, so I'm "fairly" happy that she's been looked after well.


I'll get onto having another go when time permits.


Cheers


SkidT

[Falcon 269]

Dave48's advice is sound but iIf all the pistons were clean and moved in/out OK, then you probably don't need to go the full brake overhaul route right now. 

Ayjay's right on the money with what he says about bleeding the front calipers.  It can sometimes take ages to rid yourself of all the air in the lines and caliper bodies.  Patience and all the various tricks he mentioned will work in the end.

[Phil TK]

  Patience and all the various tricks he mentioned will work in the end.

And not forgetting your own advice of cracking the bolt on the top banjo to bleed air out of the junction. Worked brilliantly for me when I first learnt the method and now I always do it when changing fluid/brake overhaul.

[JayB]

How'd you get on then? All OK and good for 1 / 2 finger braking now? Mine is. I had thought I was going to need an R1 master cylinder, but they are fine as is.
Think possibly my pads could do with changing, lots of winter use and been sat around loads, they bite fine but have no real feel to them.

[old son]

I had an issue once when the front brakes would not bleed through. Took it to the shop and they replaced my Pazzo lever with a standard levers and bled the thing through in a couple of minutes. Something to do with the original lever and original bolt forcing the lever on the master cyclinder right in whereas the Pazzo's obviously did not.

[JayB]

I had an issue once when the front brakes would not bleed through. Took it to the shop and they replaced my Pazzo lever with a standard levers and bled the thing through in a couple of minutes. Something to do with the original lever and original bolt forcing the lever on the master cyclinder right in whereas the Pazzo's obviously did not.

That is definitely worth mentioning and remembering...

[SkidT]

Hi guys,


Sorry, been away for while and not checking my old posts.


Eventually gave up, cable tied the lever and left for twenty four hours and as if by magic, when I returned to it, had good lever pressure. It seems to have stayed that way since, although with the weather, it hasnt seen much use recently.


As an aside I also have non standard (shorter) clutch / brake levers. Didn't even consider this as not helping at the time, but now that someone else has mentioned it, it seems common sense!

[JayB]

Since this, I have replaced my front lines with braided ones. I was dreading the bleeding process, but after a chat with a bike mechanic I know, he advised to do it in conjunction with some other jobs and let gravity do most of the work for you.
 
I used 2 empty glass coffee jars, 2 lengths of car washer tubing and just filled the cylinder up, bled the master to the top bolt on the brake lines and then left the bleed nipples at on caliper open at a time.
 
Within about 10-15 minutes you start to see traces of fluid appear which you can help by tapping the lines wherever you can get to them. The start pumping the lever, re-filling the reservoir etc.
 
Works a treat.

[JoeRock]

How'd you get on then? All OK and good for 1 / 2 finger braking now? Mine is. I had thought I was going to need an R1 master cylinder, but they are fine as is.
Think possibly my pads could do with changing, lots of winter use and been sat around loads, they bite fine but have no real feel to them.

What's the difference between the R1 m/c and the Fazer one? I'll be getting some braided hoses soon anyway, so if I were to swap the m/c over it'd make sense to get it done then! From what I've had so far on the Fazer the brakes definitely aren't bad, but they do seem a tad wooden, I'm finding I'm having to squeeze quite hard on the lever compared to my old bike for the same stopping power?

[JayB]

I was going to do the same, but didn't, now I can't work out if it's the cyl or the unknown pads fitted by previous owner (probably cheapo shit)
I have plnety of pressure with 1 or 2 finger braking, but it just feels they aren't biting hard enough, hopefully crap compound and will be better once replaced.
I think if it needed the R1 cylinder, it would have found it's way on the bike during the production run?