Topic: No pressure from dual disks CB550

[exponent]

So I'm getting along with my dual disks and am now trying to fill the system with fluid. So far I have no pressure in the lever but fluid coming out at both bleeders, and all banjo fittings. My setup is a double banjo into the MC and two lines directly to each caliper. I'm thinking either to try a vacuum bleeder and suck fluid through the bottom, or the master cylinder I bought is no good and needs to be rebuilt or replaced.

This is the mc I bought:
https://www.ebay.com/itm/7-8-Brake-Master-Cylinder-Honda-GL1000-GL1100-GL1200-GL1500-GoldWing-Dual/353137632704?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[Don R]

 Bleed the m/c at the top fitting, it's probably full of air. Cover all painted surfaces with multiple layers of plastic / cloth. 

[robvangulik]

Bleed the m/c at the top fitting, it's probably full of air. Cover all painted surfaces with multiple layers of plastic / cloth.

Pushing the caliper pistons back achieves the same, just do it SLOWLY....

[Rookster]

If you are starting with a dry master cylinder then leave the caliper bleeders alone until you feel pressure at the lever.  Work the lever in and out in short pulls not long pulls back to the grip.  You should start to see bubbles coming out of the hole closest to the banjo,  The hole closest to the lever will also bubble but much slower.  It may take some time but work the lever until you can build up pressure.  Once you have pressure and resistance at the lever you can go ahead and use the bleeder screws on the caliper.

Scott 

[exponent]

If you are starting with a dry master cylinder then leave the caliper bleeders alone until you feel pressure at the lever.  Work the lever in and out in short pulls not long pulls back to the grip.  You should start to see bubbles coming out of the hole closest to the banjo,  The hole closest to the lever will also bubble but much slower.  It may take some time but work the lever until you can build up pressure.  Once you have pressure and resistance at the lever you can go ahead and use the bleeder screws on the caliper.

Scott

Thanks I'll start doing it that way, have been squeezing the lever in various ways and have gotten some bubbles but not many lately. Not sure how long it takes to build pressure so I'm wondering when/if to switch mcs

[maxheadflow]

Are the discs mounted behind the forks instead of the front?  If so you need to remove one bolt and twist them so the bleeder points up.

[Kevnz]

Whilst trying to expel the piston from my caliper, I was able to build up pressure without opening the bleed nipple, just by slowly pumping the lever. The bubbles that come up are tiny, so it takes a while, but I prefer to do it this way because you don't get brake fluid over the fittings stripping the paint. Once you start getting some pressue, you can just tie the lever to the 'bar ( but not hard in) and leave it for a day or so.It will then self bleed. Easy and clean if you are in no rush.