Brake bleeding problem

[RETRO]

Hi all just fitted new caliper pistons and all seals to my gsx750et bled both calipers and just had a spongy brake that pulled right into the handlebars, but if i pull the leaver in and flick it out a few times the brake goes rock hard and the brakes are jammed on, whats causeing this is it because i have rubber brake pipes or is the master cylinder knackered.

[Killer2600]

Hi all just fitted new caliper pistons and all seals to my gsx750et bled both calipers and just had a spongy brake that pulled right into the handlebars, but if i pull the leaver in and flick it out a few times the brake goes rock hard and the brakes are jammed on, whats causeing this is it because i have rubber brake pipes or is the master cylinder knackered.

You have air in the system, probably in your master cylinder if you haven't bleed it there first. I can't help you anymore than that, apparently for me bleeding motorcycle brakes is an art I've yet to master cuse I catch hell doing mine.

[chef1366]

Clean the master cylinder itself. There are two holes and the small one is like a return line. Make sure it is free of debris. Before putting the brake lever on push the M/C piston in with a phillip screwdriver. This pushes the piston in farther in than the lever itself and air likes to hide in that small distance. You should see bubbles rise to the surface of the M/C resevoir. Do this little trick with the resevoir cap off.

[CanadaDan]

To take the art out of bleeding brakes I use Speedbleeders... damn great invention!

www.speedbleeder.com

They don't have any GS's listed in their application chart but that only means they haven't posted the compatible fitting. I have an e-mail into them now for the right size. I will post when I know.

I've used them on the airhead for quite a while. No adverse effects and I can flush and bleed both callipers in 5 minutes by myself.

[twistedwankel]

[quote=CanadaDan;664615]To take the art out of bleeding brakes I use Speedbleeders... damn great invention!
www.speedbleeder.com
quote]

These are recommended on the Jay Leno website for old cars when you would need two people to bleed the brakes. With our little bitty bikes I don't think one can justify the cost? I can easily reach the brake lever and the bleeder screw - just have to close the screw before releasing the brake lever is all.

They are a really good invention tho'.\\/

[RETRO]

I bled the master cylinder and the calipers again but stil no real brake to speak of until i pull the leaver in and let it flick out then the brake becomes solid after afew pumps but the pipes are presured up and the brake are locked on, why is this happening?

[CanadaDan]

[quote=twistedwankel;664724]

To take the art out of bleeding brakes I use Speedbleeders... damn great invention!
www.speedbleeder.com
quote]

These are recommended on the Jay Leno website for old cars when you would need two people to bleed the brakes. With our little bitty bikes I don't think one can justify the cost? I can easily reach the brake lever and the bleeder screw - just have to close the screw before releasing the brake lever is all.

They are a really good invention tho'.\\/

Jay probably gets free bleeders for every car for that

Condsidering the regular ones are $7 and the stainless are $15 it's no too bad. It's handiest when flushing the entire system with fresh fluid. You pump with one hand and pour with the other... the valve does the work of the third hand we all wish we had when wrenchin' :-D

And for the record the 1977 GS400 uses the SB7100 (M7 x 1.0 x 35.15)

[Killer2600]

To take the art out of bleeding brakes I use Speedbleeders... damn great invention!

www.speedbleeder.com

They don't have any GS's listed in their application chart but that only means they haven't posted the compatible fitting. I have an e-mail into them now for the right size. I will post when I know.

I've used them on the airhead for quite a while. No adverse effects and I can flush and bleed both callipers in 5 minutes by myself.

I dunno bout them speedbleeders, I've never had a problem with getting the fluid to flow steady out the bleeders, I just have a problem getting the air to go out with the fluid. Besides opening and closing the bleeder and actuating the lever isn't too difficult on a bike and plain easy with a helper.

[Suzuki mad]

Answer the question x 2

Hi all just fitted new caliper pistons and all seals to my gsx750et bled both calipers and just had a spongy brake that pulled right into the handlebars, but if i pull the leaver in and flick it out a few times the brake goes rock hard and the brakes are jammed on, whats causeing this is it because i have rubber brake pipes or is the master cylinder knackered.

Rubber brake hose......Could be a problem if they are bulging when you apply pressure.

Sounds like the master cylinder has some rubbish in, like emusified brake fluid, or there is an air lock in the system.

It could also be that the internals, such as the spring is jamming due to a build up inside outer part of the master cylinder.

Suzuki mad.
Have you tried cable tying the lever to the hande bars to allow any remaining air in the system out?