Hello,

I didn't ride my bike for about 3 months and when I took it out today I noticed the front brakes were very spongy. the brakes would work but the lever travelled very far almost to the grips.

I figured I would need to bleed the brakes and started on it without using a vacuum pump bleeder. Just the regular plastic tubing in a cup, pull lever open valve close valve technique. I am not sure what went wrong but I never got back my brakes after that first attempt at bleeding. the brake lever has no resistance and freely moves back and forth now. and I have zero brakes.

I then bought a mityvac brake bleeder and tried bleeding the 2 front calipers and got plenty of air bubbles and it never stopped bubbling. I feel like there is leak somewhere.

When I tried to bleed the master cylinder, all I would get is air under vacuum, no brake fluid. and the pump would not hold vacuum at the M/C, it would keep losing vacuum. Is this normal?

any suggestions?, thanks in advance.

Is the Res full?

Yes I kept an eye on it topping it off.

Maybe you can do this...attach MiteyVac to left side caliper..open screw.Tape the lever to the bar.Fill res.Pump miteyvac till fluid begins to drop in the res.MAKE SURE the hose is fitting TIGHT on there.You could be pulling air in and not realizing it.(at the screw/mitevac inline).Also..if the line has a serious amount of air in there...it may take a while to get it out and get fluid running down that line.Probably longer than you had hoped for...but pumping the line should cause the new fluid to start entering in spite of the air.The lever probably IS trying to build pressure...even if it doesn't feel like it for a bit.The air will not block the fluid from gravity pulling it down.

HUB describes this bleed process very well...the 'HOW TO'.Maybe he'll show up for ya...

I haven't done an 'air in the line' bleed for a long time.I always just replace fluid when the lines are full.So I'm not dealing with loss of lever action.You situation is different....I stopped using my miteyvac because it did as you're describing...loss of vacuum.But if I recall..it was air getting past the bleed line at the nipple.

Plus I've never had a line leak...which you MIGHT have...IDK.If you do...all the bleeding in the world won't work.Check you lines and banjos.Make sure there's NO fluid seepage on those.If there is...there's probably air entering as well...

* Last updated by: Grn14 on 9/5/2015 @ 9:33 PM *

how likely or unlikely is it that the vacuum is pulling outside air from leaks in the bleeder valve threads? I saw some brake bleeding videos on youtube and they were for cars recommended removing the bleeder valves and wrapping it with teflon tape for a tight seal. Is this necessary for bikes?

I made a video of the symptoms. Zero braking, the lever bounces back and forth. http://vid3.photobucket.com/albums/y65/bigjoe87865/20150906_111915_zpsdk1qxtee.mp4

* Last updated by: bigjoe87865 on 9/6/2015 @ 9:35 AM *

Very possible.

Can't see the video but sucking a tiny bit of air past the bleeder valve threads is normal. That air is getting sucked right back ou so no harm inside your hydraulic system.

The Mity-Vac I have (it's one of the more expensive models) is good for shit. JMHO. My injectable marinade syringe has more f%$$ing suction that that piece of shit and it cost as much as a jar of marinade.

Keep at the master. It often takes a lot of pumping and tapping on the pipe and master cylinder especially if it got a dry spot in it. Once the fluid fills in the dry spot, it will flow and you will start to get fluid out. Bleedl til you see no large bubbles. A few tiny bubbles, you will never get rid of those. That's just air past the bleeder threads. then proceed to the RH caliper and then the LH last. If you have a two line after market setup, doesn't matter which caliper you bleed first. Go back to the MC and bleed a bit more, then the calipers.

Really man, try bleeding with just the bleeder valves and pumping the lever. See if that's not 100x more effective than the titty-vac breast pump for virgins.

1. Run the old 'bench prime' on the bike.
a. The hose, recovery bottle, and paint safety.. is the given.
b. Open the master's nipple just a crack, as you feel the pressure release at the lever.
c. This leaves the threads as tight as possible, but lets the fluid run, not suck air and trick you this way.

2. The lever action is handcuffed to the DTT (lol)
a. Threshold: is the chamber mixed with air.
b. Trigger: is the lever you just keep pumping and pumping with that nipple open.
c. Discharge: is the air and dot4 down the tube.

3. The Open/Close Method In 2 Moves.
a. The nipple shows fluid only with every pull of the lever/push of the pedal, my threads are tight.
b. The secret is pump till you have arm pump, no bubbles, you keep sucking those in.. "for every action there is yada."
c. The last pull to the lever/stroke of the pedal, that nipple is closed before you get there.

A. Troubleshooting Master:
1. Lever goes to the grip = Prime Master's nipple first.
2. Lever feels spongy, never touched the master's nipple = Prime at the master's nipple.
3. Lever does not return to proper feel after trying both 1 or 2 = Bleed banjo bolt.

B. Procedural Direction:
1. Start at the calipers.
2. If there is any pedal or lever feel losing pressure, close caliper, bleed the master's nipple.
3. The pedal must return to full-hard pressure, then open caliper nipple and keep flushing at the caliper, etc.

"The Mity-Vac I have (it's one of the more expensive models) is good for shit. JMHO. My injectable marinade syringe has more f%$$ing suction that that piece of shit and it cost as much as a jar of marinade"...

I have one also..the more expensive one.Doesn't it have a pipe running down into the canister?I wonder if?...filling the canister up past the outlet on that line in there would change how well the pump actually pulls?I never tried it.Instead of having all that air volume in there from the start,maybe fluid would somehow make the pumping action work better?IDK.I'll try it next time and see.Getting it to start pulling can be a pain.But I always started with the canister empty.Probably won't be any different.What do I know?

I do know I've used it several times...and it worked well.But I went back to doing it the book way.Then again...I've not allowed the lines to get a bunch of air in there either.I think as was mentioned...the key here is to make sure no air is getting through the nipple...the threads I mean..or the fitment of the tubing.That HAS to be sealed tightly.

* Last updated by: Grn14 on 9/6/2015 @ 5:08 PM *

big the key to using the vac bleeders is not to cause too much vacuum. When you're bleeding, don't use any more than about 5 hg of vacuum. I usually don't exceed 3. The reason is this allows the brake fluid to seal the threads of the bleed valve. When you're sucking air bubbles, basically you are just causing air to be drawn thrown the threads.

The vacuum bleeders work extremely well and easy. I will say it takes a bit of tinkering to figure out, but once you do you'll never use the manual process again for anything you need to bleed. One key is to avoid hitting 25 hg of vacuum.

I usually take my syringe and push fluid back up to the master and suck out the bad till I see good with a baster. I have never had a problem with air bubbles and my lever pump regimen is cut in half.

Interesting.Now that you mention this...I wonder if I could draw the fluid up with the miteyvac(attached to the master) from the slave nipple?Attached of course to the DOT bottle. I think I considered this once before...but never tried it.You know..tape the lever back or something?In theory,it should work.

Interesting.Now that you mention this...I wonder if I could draw the fluid up with the miteyvac(attached to the master) from the slave nipple?

big the key to using the vac bleeders is not to cause too much vacuum. When you're bleeding, don't use any more than about 5 hg of vacuum. I usually don't exceed 3. The reason is this allows the brake fluid to seal the threads of the bleed valve. When you're sucking air bubbles, basically you are just causing air to be drawn thrown the threads.

The vacuum bleeders work extremely well and easy. I will say it takes a bit of tinkering to figure out, but once you do you'll never use the manual process again for anything you need to bleed. One key is to avoid hitting 25 hg of vacuum.

Makes sense. Opening the bleed way open to create the least resistance probably is more effective for pushing fluid through with the MC. When you're sucking it through with a mity-vac, it's probably more important to maintain suction which mean opening the bleed just crack. Maybe I am opening my bleeds too much. I have been trying to use as much suction as possible and opening the bleeds way open. I'll give it one more try soon.

I'm interested to know if you got your brakes fixed

Rook I usually unseat it, then snug it closed, and ~60º bleeding.

Mine is reversible.It squirts as well as sucks.

You sir, have the opportunity to earn untold quantities of cashish.

I have a 2008 and when that happens I do the mityvac to the mc only. Only a little bit and have brakes again.

Thanks.

You sir, have the opportunity to earn untold quantities of cashish.