I rebuilt my front brake system a few years back and it was a royal pita to bleed...I started using the vacuum pump but could not get a good enough seal at the bleeder fitting, and pumping the lever was taking F O R E V E R! I walked away from it several times in frustration and ended up tying the lever in and leaving it overnight before I was finally able to get all of the air bubbles bled out the next day. It was a simple task that turned into a nightmare.

A couple of years later, I rebuilt the front master and flushed the fluid and replaced the pads in both systems on my son's '04 LR and didn't have a bit of trouble getting either system up and going other than a previously stripped bridge bolt hole thread in the rear caliper that I fixed with a Helicoil.

I recently changed my front pads and noticed that the front brakes were sticking and the lever was stiff, a sure sign that the bleed hole in the master cylinder is stopped up. I got the OEM master and caliper seal kits and banjo bolt gaskets and took every component off, flushed, cleaned, and rebuilt the system from top to bottom using Harley parts. I put it all back on the bike, filled the reservoir, and bled it like I did the Low Rider...

I hold my fingers over the hose banjo fitting where it connects to the caliper and pumped the lever and worked my finger on the fitting to pump the air out...fingers off when pulling the lever, on when letting it go. When I started getting fluid at the fitting after about a dozen strokes, I let it hang down and gravity took over. About 10 minutes later, I connected the line to the caliper and put a hose on the bleed fitting and pumped fluid through the caliper and into a jar. After I had good flow into the jar, I did a final bleed and let it sit while I ate lunch, 30 minutes, then did a final bleed after tapping on the caliper and master with a small hammer to release any trapped bubbles. I have used this method four times now on both front and rear, and each time I didn't have a bit of trouble bleeding.

 

Thanks. Will changing to new lines on Monster 900 in a couple of weeks.

 

I use a syringe to pump fresh fluid into the bleeder screw on the caliper forcing fluid into the lines, collecting in the M/C. Takes 30 seconds. Done.

 

There you go. I have one of those fancy Phoenix Injector, But a syringe would do the exact same thing in this situation. Cheap and effective.

 

I have used the speed bleeder on my Street Bob multiple times to successfully bleed my front brake, even when swapping in a brand new master cylinder.

However, I replaced all 3 front brake lines on a friends Street Glide with stainless lines and the speed bleeder and old-school method would not work. I went to Autozone and picked up a MityVac as a last ditch effort and am now a firm believer in them. I had all the air out in less than 10 minutes flat! I will always use and recommend the MityVac in the future.

 

i just let the hose hang til fluid flows freely, then attach them ti the caliper and let them gravity bleed. after it's all flowing, i do the lever pumping and then ziptie the lever to the bars for a few hours... up front anyway

rear almost the same but no gravity bleed or ziptie. just the hang and the pumping lever

 

I have a vacuum pump and typically it works well. However, unless you can get a good seal on the bleeder valve it is not efficient.

It seems like pumping fluid in from the caliper is pushing the air that collects behind the pistons up through the system to the master and will take longer to get it all out than if you pumped fluid from the master down...

Our shared experiences prove that there are many methods that work somewhat mostly, and some that work well mostly, and there are others that work great...however, I have not found one that works really great with bleeding the front system of a Harley Davidson Dyna...yet.

 

I have rebuilt dozens of brake systems, both front and rear on various makes bikes. I start at the master cylinder. Fill the reservoir but leave the brake line disconnected. I put my thumb over the hole where the brake line hooks to the MC and pump the lever. You feel vacuum at first then then after a couple of pumps you feel pressure from the now blead MC, forcing your thumb off the hole. I hook up the brake line and open the bleeder a turn or so. You have to make sure you keep the reservoir full. When the fluid starts to run out of the bleeder, only takes a few seconds to a minute, I close the bleeder. If the bleeder is truly at the top of the caliper you're done. At that point you can pump, hold, release bleeder, tighten bleeder, release lever a couple of times to make sure.

Rear exactly the same. Now on my 08 LR the rear bleeder is NOT at the top of the caliper. I leave one of the mounting bolts out and rotate the caliper so the bleeder is at the top. Rear is much quicker because the brake line is much shorter.

 

What ever method you use, cover all painted surfaces with rags, towels plastic bags because DOT 3/4 fluid will eat paint. If your bike is older and uses DOT5 no real worries as it won't eat the paint but still cover the surfaces around the bike. You don't want to be washing your bike because you got brake fluid sprayed out all over. And for Gods sake don't let brake fluid run down onto your tires. If it does use some brake cleaner to clean it up before you ride.

 

I have also bled the master first and then bleed the system but it is really messy and it just seemed to me that bleeding the master but with the brake line connected is knocking out two components at once...then the only thing left to do is to force and bleed the air out from behind the pistons...