brake bleeding

[turkeyroll60]

My 82 GS450 TXZ has a single disc brake in the front and I just opened up the master cylinder after felling the brakes go soft. There was almost no fluid left in the reservoir!! So I added more dot 4 fluid and now I cant get any pressure in the line to properly bleed them. When I open the bleed screw fluid comes out and when I tighten it back up and pump them, I get no improvement. Right now I have the brake lever twist tied to the handle and the bleed screw opened about a half turn. The master cylinder cover is full and the cover is on. I will let it sit overnight and see what I get in the morning. Anyone have any suggestions?

[LarryC]

Ya need to put some vacuum onto the bleeder to draw fluid through. I had the same problem with mine. Get some fluid drawn thru the system to get it primed. FYI my mouth wasn't strong enuff. I needed some mechanical assistance- in my case I found a weed killer sprayer which developed strong suction and fit the bleeder nipple.

[Steve]

You really need to learn how to properly bleed the brakes.

One method is to pump the lever several times, then hold it. Briefly open the bleeder, then close it. Release the lever, pump and repeat.
The problem with this method is that it will only compress any air bubbles without moving them, then, when you open the bleeder, the air bubble will expand, moving it along by only the size of the air bubble.

A better way is to open the bleeder, squeeze the lever (once) and hold it. Close the bleeder, release the lever.
This method will move more fluid (and any air bubbles) by moving as much as the master cylinder can push in one stroke.

Even better is to use a vacuum pump like a Mity-Vac to apply suction to the bleeder nipple. Open the bleeder, watch the level in the reservoir, as it will go down quickly. Helps to have an assistant, if possible. It also helps to remove the bleeder and wrap some Teflon tape around the threads so you don't draw air from around the threads, giving you false readings.

.

[Datsa Noydb]

DOT 3 or DOT 4 fluid is OK, but with your bleeder open and your lever tied, I think you will find your system totally empty in the morning.

[Dave_17954]

I just redone the brakes on my '83 gs650 rebuild. I used this method on mine. "A better way is to open the bleeder, squeeze the lever (once) and hold it. Close the bleeder, release the lever.
This method will move more fluid (and any air bubbles) by moving as much as the master cylinder can push in one stroke." I used a section of hose from the bleeder screw and ran it to a clear jar with some brake fluid in it so the end of the hose was submerged as to not draw any air back into the system. I done it by myself and it took me maybe 10 minutes to get mine primed and working. Good luck to you .

[turkeyroll60]

Dave.....I tried your way and they work like a charm now. Steve, I can now say I have learned how to bleed motorcycle brakes. The problem now is the front wheel doesn't spin freely with the brakes disengaged. I had to leave it till tomorrow cause I gotta get some sleep. The motor sounds like its riding on the brake pad. Maybe I did too good of a job bleeding huh?

[1_v8_merc]

Reasons your brakes could be locking

1.)Return port clogged on MC
2.)Caliper pistons stuck
3.)Clogged brake line
4.)Slider pin needs grease(whatever it's called)

I'm guessing you didn't tear down the caliper or MC? You just bled the system?
If your brakes are sticking...you should tear everything apart and inspect!

[LarryC]

I tried that pump the lever business till my fingers fell off. Hence the resort to mechanical assistance. Pumping the lever always worked on the other 27 bikes I've had in the past 45 years. But then they were Hondas and Yamahas. Suzuki it seems follows a different........bleeder.