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I installed my new Galfer brake lines on the front and can't get any firmness in the front brake lever bleeding the brakes. I am using a mityvac. Is there any tricks to this? I have read the service manual and watched videos on YouTube and I am doing everything they are doing. It's been over 5 years since the last time I have changed brake fluid in a bike.

I've never tried this but some people pull the lever in and ziptie it to the handlebars overnight.

I'm assuming you mean one of these (I use the same one)?:


If so, I just fill the reservoir with fluid, hook up the mityvac, open the bleeder, and slowly pull it through the line, making sure the reservoir never goes totally empty. If it does, and you add fluid after its empty, there is a air bubble in there. Close the bleeder, refill, and pull fluid out until that bubble comes out. Just do that a couple of times and you will see a solid stream come out. Should be good to go then. Is that the process that you used? Did you leave the cap off the reservoir when you were doing this? I don't know if that makes a difference or not, I think I usually have mine off while I'm doing this. I just got a Galfer line for the front of my Hybrid, but have yet to get it on.

Before I got the mityvac, it would drive me crazy trying to bleed the lines on my bikes. I've bled the lines on my car/trucks a million times before without a vacuum bleeder with not problems (just need a another person lol) I guess its not as simple on a bike. I figure maybe its just smaller diameter lines? Or the master cylinder is smaller and doesn't put out as much pressure? I don't know.

Good luck!

i replaced a line on the rear of a bike and it wouldn't pump up manually or with the mighty vac. I put in a master cylinder rebuild kit and then it pumped right up.

Side note, make sure you don't set down your mighty vac pump lower than the reservoir cup while under vacuum. I set it down for just a second and the pump filled with brake fluid which ended up corroding the inside of the pump. My new upgrade costed me a lot more time and money than I thought it would. It wasn't broke until I tried to fix it lol.

I have the cap off the master cylinder and have kept it filled. Been pumping the brake and cracking open the bleeder and it just seems I'm not getting anywhere. I guess it might just take a long time to do? I will try some more today.

I had a hell of a time when I did my brakes for the first time. They are not done like regular car brakes. It's much simpler once you read the manual, let me see if I can find my manual....

This is what cyclepedia says....I don't recall this working though...

Pump the rear brake pedal up and down about four times, then hold down the brake pedal while loosening the air bleeder screw.

Close the air bleeder screw and perform this same procedure until clean brake fluid flows from the tube. The brake pedal should feel firm.

Make sure to top off the master cylinder with brake fluid when done. This procedure is the same for the front brake system.


If the brake pedal does not become firm try bleeding the banjo bolts on the master cylinder, and caliper. This is done by pumping the pedal and holding it down while loosening the 12 mm banjo bolt.

javjacob wrote:I have the cap off the master cylinder and have kept it filled. Been pumping the brake and cracking open the bleeder and it just seems I'm not getting anywhere. I guess it might just take a long time to do? I will try some more today.

It seems like the issue is getting the line filled with fluid. I would fill the reservoir, put a zip tie on the lever to hold the brake on, put the mityvac on the bleeder, open the bleeder, and pump the mityvac until fluid starts coming out. Then bleed like normal after that.

I think its not as bad on a car because you have a brake booster on there to help pressurize the line. Maybe the small master cylinders on our bikes just don't have enough pressure to initially fill the line?

I have done everything mentioned. I have pumped more fresh fluid through than what the brake system holds actually. I noticed the brake line goes upward before going down which is how the front brakes are on our bikes. Not sure if that is trapping air but there is no good way to keep the line all below the master cylinder. Or could my master cylinder need to be rebuilt? I wouldn't imagine so since my brakes worked just fine before though.

I seen a video of a guy reverse bleeding the brakes on a bike and that looks like a good way to go. He had a system that was just a syringe and a hose you fill with brake fluid and pump it in through the bleeder and out the master cylinder. I tried searching for one and can't find it though.

I typed in a few different key words on the search and found one on EBay and bought one. Just have to wait for it to get here.

I would take it off the bike and mount it somewhere else to get the cylinder higher.

+1 on the mightyvac. This used to be a chore before I got one.

I fill a syringe with fluid and attach it to the bleeder on the brake caliper, make sure there's as little air in the tube that attaches to the bleeder nipple as possible. Leave the top off the master cylinder, wrap a wrag around it, then crack open the bleeder nipple and slowly push the fluid in. Air likes to rise so the fluid your pushing in will push the air right out the top of the master. This has worked well for me.

The biggest problem I have had is the loop of hose over the bars. I unbolt the caliper and put some thin hardboard between the pads, letting the caliper hang so that the hose runs down hill from master cylinder to caliper, then I just bleed the normal way. If the line is dead dry, it can sometimes be a ball ache getting the fluid started, in this case I use a syringe to suck it through to the bleed nipple. Once I have a good firm lever, I pump the brakes up and cable tie the lever to the bars, give the line a few good flicks to dislodge any small air bubbles, and leave over night. Cut the cable in the morning, remount the caliper and go riding!

I got my reverse bleeder and that did the trick. Best $11 I ever spent.

I just did this same method two nights ago when I put a new stainless line on my bike. Didn't ride it much yet, but all seems well

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JL4049 wrote:The biggest problem I have had is the loop of hose over the bars. I unbolt the caliper and put some thin hardboard between the pads, letting the caliper hang so that the hose runs down hill from master cylinder to caliper, then I just bleed the normal way. If the line is dead dry, it can sometimes be a ball ache getting the fluid started, in this case I use a syringe to suck it through to the bleed nipple. Once I have a good firm lever, I pump the brakes up and cable tie the lever to the bars, give the line a few good flicks to dislodge any small air bubbles, and leave over night. Cut the cable in the morning, remount the caliper and go riding!

I have found raising the master cylinder up high works well also, along with tapping the MC and flicking the lever to motivate the air bubbles.

javjacob wrote:I seen a video of a guy reverse bleeding the brakes on a bike and that looks like a good way to go. He had a system that was just a syringe and a hose you fill with brake fluid and pump it in through the bleeder and out the master cylinder. I tried searching for one and can't find it though.

This is what I do when to ensure all the air is out of the system. Works every time.


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