FJ1100 bleeding woes

[SausageNips]

I just finished doing my forks and I replaced the front pads since fork oil had covered them.  While bleeding the system, I bled the air out of all four points (the two calipers and the 2 anti dive units).  The problem is that i don't feel any resistance on the brake lever.  Also, even with all the bleeder valves tightened, I see air bubbles coming up in the reservoir at the master cylinder.

I'm not sure if there is a problem with the master or what's going on.  I don't see fluid coming out anywhere, so I'm not sure what's going on.

Any advice is greatly appreciated - thank you!

[Tuneforkfreak]

When I bled my FJ clutch system it would NOT bleed out with standard bleed procedures and I messed with it for what seemed like hours. I got a brake bleeding vacuum pump and it solved my problems in one shot. Those master cylinders dont push enough fluid to ram the air out so I think the air just moves around in there ticking you off and playing games with you. I'd never dream of not using a pump after I learned what good deeds it had done on that clutch system.

[Pat Conlon]

As Mike says above^^^ a MityVac is your friend.....every tool box needs one.

While I've found a vacuum pump the fastest, easiest, there are a couple other techniques you can try:
1) Reverse bleeding: Take a large syringe full of brake fluid and inject in from the caliper bleed screw. This pushes the air bubbles up to the (open) reservoir, the way they would naturally flow.
2) Lever tie method: If you have the time, when you can't build up line pressure, tie the brake or clutch lever back about 1/2 the way. Let it sit overnight. The air bubbles should migrate up into the reservior and the next day you should have enough line pressure to complete the bleeding process.

Hope this helps.  Pat

[fj1289]

Another thing to try is cracking open the banjo bolt at the master cylinder slightly (wrap it in a rag to keep fluid off everything!) Then a gentle squeeze on the lever and tighten the bolt again while holding the lever. Doing that a couple times usually helps me get enough air out of the system to the traditional method to work - especially if I've completely disassembled the whole system.

[FJ_Hooligan]

If you see air bubbles coming up in the master cylinder then that means there's still air in the line.

Stop trying to push the air downhill.  Take a break and let the air rise up to the master.  Instead of squeezing the lever, just tap on it and watch the air bleed out.

[Yamahammer1200]

Being impatient, I have used a palm sander (without sandpaper, of course) to vibrate the calipers, lines and m/c to get the last bit of air up and out.

[aviationfred]

I feel your pain with having brake bleeding issues. I had a heck of a time getting my rear brake to build pressure. I tried every trick in the book to no avail.

I finally broke down and bought a vacuum brake bleeder kit. Within 5 minutes, I had a good solid working rear brake. A tool well worth the money.

Fred

[SausageNips]

Thank you everyone - I was finally able to get it firm after cleaning the bleeder screws, but I'm going to rebuilt the MC and replace the lines as I think they are long overdue

[fjbiker84]

I had the exact same issue after installing rebuilt calipers on my 84.  Finally figured I must have done something wrong and rode the bike (sans front brakes) down to the Yamaha dealership.  They said there was nothing wrong - just need to use a vacuum bleeder if the calipers are starting from a completely dry state.  I later heard that you can manually fill the calipers with a syringe first and then complete the job with the brake lever as normal.  Oh well.

[balky1]

Thank you everyone - I was finally able to get it firm after cleaning the bleeder screws, but I'm going to rebuilt the MC and replace the lines as I think they are long overdue

If your brake usually works fine no need to spend the money on MC rebuilding. I recently changed all my lines and that is definitely I would recommend.
I also had some pumping to do after replacing front lines. In the end I was tapping the lines until air stopped coming out in the reservoir. Then pumped a few times, squeezed all way in and opened the nipple, even without pressure. And worked pretty fast. I changed left/right side a couple of times.