Major problem....

[JimZXR]

I've stripped and rebuilt the callipers on my track bike, bolted up some new braided brake lines and refilled the system but now I can't get any pressure from the master cylinder! Have changed it for the one on my spare bike and still the same thing; no pressure from the brake lever!

Obviously this is a problem and I need to get it sorted so I am after any guidance on how to get it sorted. I can change the calipers for my spare set if needs be but I can't imagine the problem being the calipers as I've rebuilt a few sets previously and never had a problem!

Any help would be greatly appreciated as I'm booked into EC on September 10th for my first track day here and would hate to lose my slot!

[steve086]

Try putting a cable tie on the brake lever with the leaver into the bar over night then bleed the brakes again my tz250 had that problem and doing that fixed it.

[MadKaw]

Keep pumping.!!

Or try sucking the fluid thru. I've done mine a few times and it can take over an hour just pumping the lever if its completely dry.

[holdontight]

Keep pumping.!!

Yep do that.

[Glen]

As Dave said, if it won't pump up suck it through. Stick some hose on the bleed nipple, open it up, makw sure there's fluid in the master and suck on the hose until you see fluid. You'll probably ingest some shit but it hasn't killed me yet. That all sounds somewhat homo but get your mind out of the gutter and it works.

[Maddog]

As Dave said, if it won't pump up suck it through. Stick some hose on the bleed nipple, open it up, makw sure there's fluid in the master and suck on the hose until you see fluid. You'll probably ingest some shit but it hasn't killed me yet. That all sounds somewhat homo but get your mind out of the gutter and it works.

Use a syringe to suck it through the hose.
That way ya don't get any of that homo stuff in ya mouth..

[TONY-J]

i had this problem on my rz350 after a caliper rebuild , i tried all of the above an even changed to a bigger m/c and none worked for me.

i had a heap of air behind the pistons in the calipers since i had removed them, so i took the pads out pumped and pumped until the pistons came most the way out, then push the pistons back as fast and hard as you can at the same time undoing the bleed nipple.
do that a couple times an you will have full pressure again.............well thats what worked for me anyway.

[Kwak addict]

Did you bleed the master cylinder before you bled from the calipers?

[dougz]

Make sure your lever isn't bent, even slightly. It WILL make a difference.

I had the same problem. After 4 days of rebuilding calipers, m/c's, braided lines and getting no pressure, it turned out to be a very very slightly bent lever was the cause.

[Phil]

Did you bleed the M/C?

Crack the bango's at the M/C and see if that helps

[Johnnyflash]

Try putting a cable tie on the brake lever with the leaver into the bar over night then bleed the brakes again my tz250 had that problem and doing that fixed it.

This is good advice! Always works on a completely dry but air-tight system!

Had a similar issue on a mates R6 race bike, we spent hours and hours trying to get lever pressure, turned out that there was a misaligned gasket in the calipers after the rebuild and was causing a tiny air leak!

No fluid in the caliper meant no visible fluid leak!

You will not get any lever if there is even the smallest of leaks!

[JimZXR]

UPDATE

BIG thanks to RobRacer for coming round to help me fix the brakes!

Seems like I've trapped one of the o-ring seals on a calliper and that was letting in air as we changed to one of my spare callipers and bled it through now all is good!

Looking forward to the track day again now!

Maybe buy a new 520 chain and sprockets?!?

Big thanks to all for the advice!

[King Nicholas]

Everyone loves a happy ending...

[Johnnyflash]

UPDATE

BIG thanks to RobRacer for coming round to help me fix the brakes!

Seems like I've trapped one of the o-ring seals on a calliper and that was letting in air as we changed to one of my spare callipers and bled it through now all is good!

Looking forward to the track day again now!

Maybe buy a new 520 chain and sprockets?!?

Big thanks to all for the advice!

So I was right!!!!?

Glad you got it sorted!

[matchan]

UPDATE

BIG thanks to RobRacer for coming round to help me fix the brakes!

Good news, Rob is THE brake guy!