An update on my previous brake bleeding thread - So after tries and two bottles of HD Dot 5, still not much luck. For my 2nd attempt, I bought one of those hand pump bleeder kits. I took off and inspected the rear cylander (BTW - don't look into it when you press the pedal; Dot 5 really burns the eyes) and from what I could see it looked okay. I "pumped" out via the bleeder valve almost a whole bottle (refilling before it was empty the cylander) and and all the time saw air coming out but I figured it was from the bleeder valve threads. After, still no back brake. I figured the cylander was bad but then stompted on the brake a dozen times and behold, it grabbed! So, I guess I just can't get the air out. Someone earlier talked about a large syringe and injecting in - could I reverse the pump and force the brake fluid into the bleeder valve and get the air to come up through the cylander?

 

You should only crack the bleeder nipple enough to let fluid/air out when you step on the pedal. Put a hose on the nipple, other end to a jar of brake fluid. OK to start with an empty jar, as it will get brake fluid in it shortly. crack the nipple just a little bit. Pump brake until no bubbles come out. If you are having a problem, then once no more bubbles are coming out, pump down slowly and close the nipple while fluid is coming out. If you can't get just fluid and no bubbles to come out in the jar, then I'm gonna say your master cylinder is shot.

 

Maybe I was opening the screw too far, although at this point I'm ready to just have the dealer take care of it (plus I need a new tire or two as well). Thanks for the help. (BTW - In San francisco the only place I found to have a tire changed on a Harley, bar one shop that doesn't have a good rep, is at the dealership 15 miles outside of town - go figure! I guess I'm getting Metzler or Dunlop).

 

Fogcity123. I don't know your exact situation but I put a brand new chrome front master cylinder on my softail years ago. It also wouldn't pump up. I tried everything two or three times. I bought a rebuild kit & rebuilt it. In doing so two very small chrome flakes came out of the master cylinder. Then it pumped up in about 4 minutes. It doesn't take much to muck up a master cylinder so you might want to try that. They're kinda cheep too.

Scruffie

 

Cool, thanks. I did remove the master and it looked like nothing was there to "rebuild"? I mean, it seemed like a completely solid piece. Perhaps a good cleaning somehow?

 

SPEEDBLEEDERS,

Seriously, I cannot recommend them enough. They make bleeding brakes as simple as pumping the pedal, or pulling the lever.

If you are doing this from an empty system, crack the bleeder open and let it sit for a few hours. You'll see tiny little bubbles seeping up into the resevoir. Then when they are starting to bubble regularly, you can beging the process of bleeding. You're waiting for the fluid to disperse the air in the empty system before you can start bleeding them.

But with the speedbleeders, this process is simplified 20x over. No stupid vacuum systems, just a hose from the bleeder going to a bag, or bucket.

They even make em just for HD brake systems.

 

I havent had to do my rear yet. But, being lower than the valve could definitly cause an issue.. As a rule, I like to "gravity bleed", but this wont work. But, if you fill the master and apply the vaccuum to the open bleeder, you should be able to suck the fluid up to it(just like a straw in a drink). If it doesnt, you have a hole in your straw.. Meaning that air is leaking somewhere between the valve and the master. Just make sure the master stays full and bleeder is closed whenever it touches air. As you get fluid out of the valve, you can close it and try pumping the brake, as you already did, in order to compress the air. At that point, while holding the pedal down, under pressure, crack the bleeder valve open (you can see it a little easier if there is clear hose on the bleeder and the other end in a bottle with fluid in it). When the pedal bottoms out, close the valve, making sure the pedal doesnt release at all until the valve is closed. I know it gets frustrating, but you've come this far, step back, take a deep breath and remember to use the KISS(Keep It Simple Stupid) method.. Good luck..