Front Brake Bleeding Issue!?!

I have owned an 82 XJ650J for less than a year. The front brake seemed really hot after a very short, first-of-the-season ride, and felt like it was engaging. So, I put new brake pads on it and also cleaned the caliper and master cylinder. I could not believe how much gunk was in there!

Now I am trying to refill the line with fluid, and I just can't make it suck the fluid through. I am following the procedure perscribed in my shop manual, where I have a tube in a jar of fluid, and I am loosening the bleed screw and squeezing the brake, tightening the screw, and releasing the brake. I get a few bubbles occasionally, and fluid is being sucked and spit out the end of my drain line from the jar, but it does not seem I am making progress getting fluid pulled into the system.

Did I likely mess something up?
Is is possible she is not sucking fluid into the system because the lines are also dirty?
Am I just doing it incorrectly?

Thanks, guys!

 

put some teflon tape on the threads of the bleeder but keep the little hole on the end clear
put it in tight but not quite sealed, now do the clear tube to the empty jar
now fill the master cylinder, start pumping the lever, careful it will squirt all over if you go too fast
forget that tighten loosen stuff
sometimes if the lever is held right fluid and bubbles will just run out
about a hundred squeezes later you should get some brake and very few bubbles, quit for awhile tighten the bleeder, let it set a hour
then just crack open the bleeder and do it again, till the bubbles are gone
try if possible to turn the bars so the line goes up all the way, no up then down then up
don't let the master cyl get empty, cover the tank with plastic
if it doesn't try to squirt up all over the place, the tiny hole in the bottom of the master cyl is plugged
keep some rags handy
your not sucking up from the jar, you pumping down

 

Another trick is to fill the master cylinder and use a bungee cord to hold the brake lever down. Let it sit over night and then check for soft brakes. Best thing is to find someone with a Mity-Vac and use it to bleed the brakes.

 

is that Mity-vac anything like a shop-vac with some reducers ?
i hear somebody has a gadget that pumps fluid in from the wheel up ?

 

I had the same problem bleeding my rebuilt bone-dry front brake system.

I ended up using about 4 feet of clear tubing, one end attached to the bleeder valve and the other one to a vacuum source to basically "suck-start" the bleeding process. Once you see fluid coming through, you can switch to the conventional method and finish the job.

Watch the level in the reservoir, better yet have someone help keeping it topped off and squeezing the lever.

 

Mighty vac. Worth its weight in gold. Simply hook it up. Fill the resorvoir. Pump the handle until there is about 15 to 20 pounds of suction and open the brake bleeder. Be prepared to fill the resorvoir quickly, Works well and turns a 1 to 5 hour job into a 15 minute job.
http://www.harborfreight.com/cpi/ctaf/d ... mber=92474

 

make sure the cable is adjusted correctly. if it isn't allowing full travel of the piston the fluid will not flow through the system properly

 

Perfect. Thanks a ton, guys!

 

Turn handle bars all the way to the left, this will get the nose of the MC in it's most downward position.

I've been known to let mine sit overnite then bleed again.

Lightly tapping the MC and that goofy connector behind the forks can help break the bubbles free.

 

Another method to refresh an empty system is to fill through the bleeder until the MC resevoir is full. Get a large syringe or fluid pump, connect a hose to the opened bleeder and slowly push the brake fluid up through the hose. I have a small pump bottle for filling the bottom end of my outbooard boat motor and have used it on brakes.

 

Ok, I have this same problem also and so I even get my WIFE to pump the brake lever at 11:15 at night!! (that is the only lever that seems to get pumped at 11 at night anymore :cry: )
Anyway, when I would turn the screw and pump it would start to come out into the drain hose, then, when tightened then released, it would flow back into caliper! Does this mean the bleed screw is still loose??? I did this last season and it worked perfect! Why the trouble now :evil:

 

Well, i just had this problem kinda. I decided to bleed my brakes and long story short i got air in them (sooo my fault). Anyway, if you stand in fron of the bike on centerstand you can get the job done by yourself (assuming you dont have midget arms). I would pump the brake 4-5 times, loosen the valve on one side (While still holding the brake lever in) and then tighten and release. I would repeat this 3-4 times per side then switch, being mindful to keep the master cylinder full of fluid the whole time so i didnt suck air into the system. I had a hose leading to an empty brake fluid bottle to collect the old fluid and after about 4 hours of work i finally got good brakes. I know this would go faster if you had a partner, but you really dont neeed anythign more than a wrench and a decent wingspan to do it by yourself.

Hope that made sense

 

Has anyone ever tried this. Remove the caliper from the bike but keep the brake line hooked up. Put a piece of fence picket or something about the width of the rotor in between the brake shoes. Raise the level of the caliper above the level of the master cylinder and start pumping. Air will want to go up the tube and to the top most part of the caliper. Then have a helper or wife crack the bleeder on the caliper. Have the bleeder hooked to a hose for draining the fluid off to a suitable container. Theoretically it should work. The air should actually travel up the line instead of working against itself and being forced to go down the line. Just a thought.

 

I'm rebuilding a 1980 Maxim 650 I just aquired, and am having some problems with my front brakes. The entire front brake system was dry when I got the bike, and I've just installed a new piston, spring, and seals into the handle mounted master cylinder. But while I'm getting air pressure on the squeeze & relese, I can't get any brake fluid to move through the system. Looking at the bottom of the reservoir, I can see one hole, through which I can see the piston moving. But the piston never backs up far enough to let fluid in past the front of the piston. There is a second hole next to it which was started, but never drilled all the way through. I've checked it thoroughly and it is not clogged, and there is only the one hole opening inside the cylinder itself. It seems to be in the right place to let fluid into the cylinder ahead of the piston, but this would have to be a manufacturing flaw, which means the front brake never worked. I can't imagine that a bike with no front brakes would ever be allowed out of the factory, but who knows? So I'm wondering, is the reservoir supposed to have two holes, or just the one? I was going to finish drilling the second hole out, but I'd thought I'd check around first.

 

The second hole should have a very small center hole in it. This allows fluid to bypass the plunger and release the brakes. It is very small and hard to see.

 

Wrap the threads of the bleed screw with Teflon tape.
Puncture the openings so that air and hydraulic fluid will vent.
Remove brake line Banjo Bolt ... prime caliper with clean brake fluid.
(Use rubber syringe)
Connect Brake Line.
Open Bleed Screw
Attach - One-Man Brake Bleeder Hose and Valve.
(The "Ball-bearing check-valve type is very good)
Pump the Brake Lever slowly until fluid begins to move.
When it does ...
Pump until clean, fresh, fluid is exiting the bleeder valve!

 

Ah Ha! There was indeed a clogged pinhole at the bottom of the second partially drilled out shaft. I cleaned it out with a bit of wire this morning. I'll reassemble and re-mount the brake system tonight after work. Hopefully this will get it.