Front brake fluid leaked when filled correctly

[Player07]

As title states I flushed the brake fluid on my ninja and filled the reservoir to the top line as per the manual and when I closed everything up and started tightening everything up, brake fluid started seeping through.

I took out brake fluid and closed it back up and overnight even more leaked out and I just cleaned it up. Now the level of the fluid doesn’t even match where it’s “supposed” to be. But it’s not leaking out anymore.

Anybody ? I just want to know if anybody else is the same or if something is going on with mine. It’s above the lower level line and if you look the glass window you can’t see where the level is.

P.s I did take out the cap and bellow and cleaned both.

[DannoXYZ]

How does brake-fluid climb uphill by itself?
Or does it only leak when you start tightening top metal cap?
Where is leaking fluid appearing?

Do you have plastic piece between rubber bellow and metal cap?

[Player07]

It starts to leak when I tighten on the cap. When refilling it I was sitting on the bike and keeping the bike straight up and the handle bars horizontal so that it would be level.
If I was to set the bike down on its stand (with the brake fluid level at the line) and no cap the brake fluid would start to come out because how full it is. I don’t know if that matters but just throwing that out there.
If your sitting on the bike the brake fluid is coming out the left side of the reservoir. Where the reservoir and cap meet.
I did not notice a plastic piece. I just noticed the bellow and cap. Maybe I just didn’t separated them ? Or would I have noticed the plastic piece right away ?

[adouglas]

According to the parts diagram (see attachment) there's a cap, a reservoir, and a rubber gasket/bellows piece. So not a lot to go wrong.

Sounds as if the leak is coming from the line between the cap and the reservoir body. I no longer own a Ninjette so I don't recall whether the rubber part gets sandwiched between the cap and reservoir body (i.e. whether it acts as a gasket) or not.

So assuming the rubber part does act as a gasket and assuming you put it back in place properly....

Did you torque the reservoir cap screws correctly, or did you use German torque (gutenteit)?

If you overdid it, you may have distorted/damaged the rubber part.

If you really bunged up the screws, you may have stripped or warped something and the cap isn't fully sealing.

[DannoXYZ]

Sorry, the plastic piece only exists on the earlier pregen bikes. Did you pour in brake-fluid above or below the rubber bellow? Ok, let's try making the reservoir perfectly level first:

1. loosen brake-lever clamp on bar slightly so you can rotate master-cylinder/reservoir forwards and backwards

2. put bike on side-stand, maybe with a 2x4 under kickstand?

3. rotate bar slightly to left so reservoir is level left-to-right

4. rotate reservoir forwards/backwards so it's level fore-aft, top should now be perfectly flat

5. tighten brake-lever clamp

6. unscrew reservoir cap, being careful not to rotate handlebar

7. remove cap and rubber bellow.

8. inspect bottom of cap and top of reservoir's mating surface to ensure they are both flat and even.

8. What is level of fluid now? add fluid so level is in middle of sight glass

9. carefully lower rubber bellow down reservoir, make sure edges are even and flush with top of reservoir

10. carefully lower top-cap and make sure it seats over rubber around edge evenly all around

11. tighten screws, go back and forth for even clamping.

[Player07]

I was almost worried there for a second thought I was missing a piece !
I admit I just used German torque, which had me laughing pretty good!
Everything is level as per your instructions JacRyann. But you said only to the middle of the sign glass but in the manual it states to the top line and that’s what I did and why I’m surprised it started seeping out like it shouldn’t be that full.
The mating surface , cap , and rubber gasket are all in good condition.

[DannoXYZ]

Sure top-line is good, reduces chances of sucking in air.

When placing rubber bellows back in, don't pop it straight down. Lay it down one corner first, then gradually drop the rest in gently. Prevents trapping too much air underneath it which can blow out fluid when you put cap on.

[Player07]

That’s what I did filled it to the line like I’m supposed to.
That’s why I’m suprised that it was leaking.

[NinjaBraap]

When filling you're supposed to make sure the reservoir is level, which isn't necessarily the handlebars being level, also be sure to put a shop cloth or towel around the base of the reservoir to catch any spillage. If it leaks when tightening, tighten it down (goodentight is fine, just don't over tighten or strip), recheck your level, and clean up the leaked fluid. If it continues to leak after that, you've got a leak and need to track it down and fix it. If not, don't worry about it. A bit of fluid while tightening happens all the time, and isn't much to worry about. It's when it's leaking after you've tightened it down and cleaned up you should be worried about.