st brakes

[ash]

Now guys i dont usually ask for help but this time im gona,
New front master cylinder piston fitted, new seals all round, brakes bleed ok no bubbles left in system, why the fook am i still getting spongy brakes and the lever when pulled hard comes right back to the bars,

[Thezedsintheshed]

I had the same problem a while back and it turned out to be the caliper not moveing freely on the mounting bolts that hold the caliper to the caliper bracket.

3 of the bolts were ok but the right hand caliper had one of the bolts sticking because some road salt had found its way in due to a knackered dust seal on the bolt

[ash]

Ok cheers, looks like thats gona have to be checked out,

[BShaw]

I might have missed this but is it on original hoses ? if not although they might look good they will expand.

[ash]

Baz they are original hoses mate, i did think along them lines of being 29 years old,

[Pigford]

Ash, check the calipers are square to the discs..... Had this on me Black Z1000..... one caliper was a bit "squiffy" and there wasn't enuff movement at the lever to take up the slack & make the brakes work.....
The disc was acting like a big spring washer....

[Garn 1]

Ash, it sounds like the usually problem of air in the splitter unit. A small pocket of air is captured in the splitter behind the front brake light pressure switch.
You will need to "crack" the switch open and bleed it as you would a bleed screw. I have known some who remove the retaining bolts and turn the unit upside-down.

The only other thing I can think of, is that you have fitted a 1/2" M/C instead of a (dual disk) 5/8" M/C.
RegardZ

[ash]

Thanks guys,ill give all the suggestions a try, thanks

[ash]

Ok guys the only thing i aint done is replace the brake pipes, still soft and spongy and sore fooking hands, If anyone has a second hand set of braided let me know,
Cheers

[Steve R]

Hi Ash,
I have the same problem with my Z1 A . I already have braided lines.

It was good but I needed to change the splitter and the brake fluid which had been in many years. I have tried unbolting the splitter and twisting, shaking it while bleeding, unbolting calipers and tipping them forward til bleed screws are at top. Using 2 of them halfords one way valves.
Still could get lever back to bar. tried with cover off master cylinder pulling lever slowly all the way in then letting it fly out after a few times started getting small bubbles coming up through fluid. Spent half an hour an evening doing this for a week and finally it was something like.

I think the problem is you are trying to clear air pockets by forcing them down which doesnt seem sensible some how. Tonight I am going to take the splitter and master cylinder off and get them at ground level, lower than the calipers and see if that helps.

Will let you know how I get on.

[BShaw]

Ash I know you ain't stupid and would have tried all the obvious,nipples up etc, It's a bummer when you gotta put your hand in ya pocket ain't it, If you are not going standard which I am sure you are not, have a chat with your local shop and make your own up, just two leads no splitter nice and simple... and cheaper...you know it makes sense

[Steve R]

Well, tried above didnt work in fact its now worse so when you come up with a solution do let me know!!

[Buckle]

http://z1ownersclub.co.uk/forum/viewtop ... hlight=dot

Try this thread Relates the tribulations I had after using silly-cone brake fluid (pun intentional)

Might be helpful?

[BShaw]

I take it you have clamped the hose just below the m/cylinder to check that, then below splitter then above each caliper in turn.

[ash]

Tell you what guys iv done loads of zed brakes, never been the easiest to do but this is really pissing me off, do i go for two new lines without the splitter, brake fluid used was dot 4 (recommended), new master cylinder seal kit and piston, both calipers are working ffree and easy, do i burn the bike now or later,