Bleeding brakes...a bit of trouble

So I got new stainless lines installed, and I'm having a bit of trouble with the bleeding.

There still seems to be a bit of air in the lines. The lever will firm up nicely, but after one pump (more like half of a pump). Is this normal, or is there still air in the lines?

I've put about half a bottle through, and done each side about 20 times with a speed bleeder.

It's been done with the reservoir open, lever in the resting position(not held against the throttle) and it still seems off.

I'm using silicone Dot 5.

Any ideas? Thanks a million.

 

the bubble keeps traveling up the line faster than you can push it out. try cracking the banjo fitting at the master cylinder while pulling the brake lever then tightening it before hitting bottom. be sure to stuff sufficient rags around the fitting to catch the brake fluid. or use a vacuum bleeder to pull the fluid through the lines.

I have been thinking about putting a block of wood in the caliper (in place of the rotor) and raising it above the master cylinder for bleeding also.

CN

 

Speed bleeders don't work well for trying to refill an empty system.

Put a wrap of teflon tape on the bleed screw (being careful not to cover up the holes) to prevent air from being pulled in past the threads when using a vacuum bleeder (recommended.)

Take a bungee cord and pull the lever against the bar, wrap it with the bungee like a big rubber band, and leave it overnight.

And I wouldn't have used DOT5. DOT3 would have been fine. But that's not a factor except that you're going to go through a lot in the bleeding process.

 

Thanks for the replies. I'll definitely put Teflon tape on, as I failed to do that, and I'm going to try the syringe method from the calipers up for the hell of it. I can't seem to get a solids length of fluid in the vacuum bleeder line, probably because it's sucking air through the threads...

 

Did you take the MC and wheel cyl apart and clear all the old fluid ?
If not, your asking for trouble.

 

The calipers were rebuilt, and the master cylinder is brand new, not just rebuilt. I cleaned out the junction block, and used all new banjo bolts and bleeder screws. The system was absolutely, positively spotless and bone dry.

I'm super excited to get this thing bled so I can try and pull some stoppies...

...Kidding, but it will be nice not to have sponges up front.

 

I stumbled upon something you might try while I was bleeding brakes this winter. Clamp the lever so the return circuit is open, then take a vibratory sander (sans pad) and work your way up from the caliper to the master cylinder. The bubble will/should burp it's way out.

 

brilliant idea! you could also substitute one of those old hand vibrators commonly found at thrift stores for cheap.


massager by bmonkey36, on Flickr

CN

 

when i taped a R/C car motor to my new lines for a few hours, people thought i was nuts.
now we're going to fondle our brakes with a vibrator !

 

Motorcycles are like women; treat them right, and they'll treat you right.

 

happy wife, happy life...

CN

 

This is why you re-bleed after a couple hundred miles.

But initially, using the vacuum from an idling car, and a catch-can attached to the caliper works well (for me). Costs about zero to build.

 

If momma ain't happy, ain't nobody happy. And I'm going to make momma happy tonight. I'm doing laundry.

 

I did the dishes this morning before I left for work.

CN

 

Funniest post I've seen on this Forum! :lol:

 

Maybe an eccentric weight / wait will help.....

" Take a bungee cord and pull the lever against the bar, wrap it with the bungee like a big rubber band, and leave it overnight.. " yep.. and turn the bars from L to R lock at intervals, think like an air bubble