Rebuilding a front master cylinder.

[neil125r]

Hi there,
I haven't long had this ZXR400 and have only ridden it a handful of times and a couple of those with NO front brakes, I have done the works to the calipers, seals, and pistons, and am now at the stage of re-building the master cylinder! I am new to all this and it has all been a steep learning curve for me.
I've been told the master cylinder rebuild kits are a nightmare, So my question is, are they? and does anyone have any tips/images etc to guide me?

Thanks very much for any help,

Neil

[masterofinsanity]

easy enough job, have a look at the microfiche to see how it comes apart and goes back together, only a circlip holding it all in.

[cargo]

Can I humbly suggest that if you are not 100% sure of what you are doing when working on your brakes then get sombody who is to do it for you.................

Your life depends on your brakes.

[neil125r]

Thanks both of you for quick relpies, both helpful.

Does look simple enough, I'll give it a go , and just make sure they work 100% before relying on them.

These front brakes have been an absolute nightmare, and it's all been a process of elemination, as the presure that builds up from pumping the lever keeps disapearing when releasing the lever... So, I'm hoping that this will be it!
I've read all the previous posts about the issues of bleeding etc. If this isn't it I think the next spare I'll be buying is a baseball bat!


Cheers

[cargo]

They can be a right pain to bleed..............must be some little hidden place where the air hides

[RedexRobB]

I use a mityvac pump to do bleed my brakes, never had an issue bleeding them that way.

[neil125r]

Yeah, pneumatic bleeder would have been handy too, but I've learnt a few tricks now for manual bleeding, and I'm pretty sure I'd bled them thoroughly, so I'm hedging my bets on it being the master cylinder, particularly as the external seal that the lever pushes on has some pretty bad scuzz on it, and it looks like there's a couple of nicks in it too.
Still, am just hoping it makes the difference, as when the preasure is there they're good, am thinking the seal on the MC is letting the air in evertime I release the lever?

[masterofinsanity]

if its letting in air when you release the lever then will it not squirt brake fluid out when you pull the lever in?

[neil125r]

Doh!

I give up! baseball bat it is then!

I'll just do the rebuild kit and see what happens...

[masterofinsanity]

from experience rebuilding the m/c did nothing i would have another look at your calipers but for the cost and little time do it to eliminate it.

[Jeppo]

When i rebuilt the m/c the circlip was a rite little C*** to get out!!!
It made a bit of difference but if your brakes are basically failing to operate I would say theres just air in the system. Maybe bench bleed the master cylinder? The mityvan systems are damn gd and easy to use!!

[neil125r]

What can I say, thanks everyone for all your replies.
Plan of action is, peform the MC rebuild, (with the help hopefully of my mate, who's a mechanic), and then get a pneumatic bleeder to do the hard work! this has been an ongoing job of 3 sets of calipers and countless bleeding (by me, by hand)!
I've got fkn wrists like popeye now!
Your words of wisdom have been soaked in and are much appreciated. I'll make sure to update with my hopeful success!!!

Cheers Lads.

[lewisdale]

why not just buy a secondhand one that you know works?

[neil125r]

Because I've already spent a fortune, and have the rebuild kit already.

Thanks