New front SS lines, no pressure and endless air

[Guest]

So, I finally got around to putting on the calipers and finalizing the front lines. After I put them together filled the cylinder and bled the brakes... for nearly 4 hours. Using the suction (the pneumatic air one), the old school method, and my boss even tried pressurizing it from the MC. The result: no pressure, the pistons didn't move a mm, and the MC completely works. How is this possible? The brake lines were not pressurizing which means there is a leak somewhere, but there were no visible leaks using the old soap n water thing. Only things I have changed is I started using DOT5 brake fluid, and the SS lines.

This MC is an upgraded Nissin MC from an 03 FZ1. Usually, like before I changed the SS lines, the fluid would squirt up at me but now it doesn't
I have checked on some other similar threads, so here are some possibilities:
- The master has gone wonky (But it worked perfectly before the new lines). Will check seals and piston tomorrow)
- There IS an air leak, somewhere. I will try filling the calipers with fluid tomorrow, then re-doing the bleed.
- The seals in pistons were wrong? (Checked one, and the boss said it was perfectly fine and shouldn't be a problem).


Pretty close to throwing the damn calipers at a wall, but they look too pretty

[azr]

I recently did my front brakes and had the same problem. Pulled a few hairs for sure. I found my bolt was loose at the handle bar, fixed that, then I left a bleeder open and started pumping and low and behold pressure built up! hope you figure out something.

[Agemax]

bled all my brakes and clutch with S/S lines and DOT 5 fluid, no problems

[Steve]

Sounds like you need to manually prime the master cylinder, and possibly purge it, too.

Remove the brake line(s) from the output, remove the lever. Use a screwdriver to push the piston in as far as you can, it will go farther than the lever will push it. That will help purge the last little bit of air from the top corner of the cylinder. When you do this, hold a finger loosely over the output, but allow fluid to come out. Before releasing pressure on the piston, close off the output tightly, so it will suck fluid from the reservoir. Doing this a couple of times should prime and purge the cylinder.

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[SqDancerLynn1]

Did you install the calipers with the bleeder pointing up ?

[exdirtbiker]

I had a similar problem with a hydraulic clutch...
Like Steve said, you must get air out of MC before anything else.
vacuum bleeder then makes life easy.

[Bonehead]

Cylinder did need to be primed. Steve is either psychic or MAN does he know bikes.

Also had to bleed the SS lines individually, to build pressure and get brakes working. WOOOOOH! I can now stop quite well. Also, switched back to DOT3 per my mechanic buddy's insight. Definitely feels far more firm than previously as well

[Brendan W]

Hate to rain on the parade but did you use 5 or 5.1 and were the master and calipers properly flushed of 3 , 4 or whatever was in before. 5.1 is ok on top of 3 or 4 but 5 can cause problems. If you use the wrong flush more so.
If you put 3 back into a system with dregs of 5 in it you might have trouble with seals soon. Sorry.
I have no direct experience , this is just what my research turned up when I was considering it for the cars.

[Steve]

Cylinder did need to be primed. Steve is either psychic or MAN does he know bikes.

I have done a little bit of work on bikes, but my personal description is usually listed as "psychotic".

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[jwhelan65]

did you install the calipers with the bleeder pointing up ?

+1...........

[Bonehead]

Hate to rain on the parade but did you use 5 or 5.1 and were the master and calipers properly flushed of 3 , 4 or whatever was in before. 5.1 is ok on top of 3 or 4 but 5 can cause problems. If you use the wrong flush more so.
If you put 3 back into a system with dregs of 5 in it you might have trouble with seals soon. Sorry.
I have no direct experience , this is just what my research turned up when I was considering it for the cars.

Calipers and MC were dipped in acid and re-powdercoated (they had to test new red/gloss black powder and thought of my parts ). They look the exact same if you ask me, but apparently its a tad cheaper. Seals were also washed a few times and dried fully.

I know of the troubles if there was 5 left in the system. However, its only if there was more than a few drops. Having a small amount of 5 inside will not be terribly destructive, but anymore than a small amount and I may have problems. However, that will be no problem for me

I have done a little bit of work on bikes, but my personal description is usually listed as "psychotic".

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You have yet to meet me Steve. Trust me on the way back you will be thinking "What the hell is that kid on?! And I thought I was psychotic..."