Disc Brake Bleeding

[mikeallen]

Hi all,

Got all my front nissin disc brake connected to my GP all ready to bleed through the DOT4 fluid.

I've topped up the master cylinder & undone the bleed valve a few turns at the caliper but as I pump the brake lever it seems the fluid level is not going down at all, am I doing something wrong here

I've pulled the brake lever in & out now for a good ten minutes or so but the level has remained the same as it does not seem to be drawing through

Complete newbie with these hydraulic disc brakes so any help much appreciated.

Thanks

[Andy Pickering]

Mike: http://scooterotica.org/forum/viewtopic.php?f=32&t=8238

Tons of great advise on this topic on this link, you might want to draw the fluid down with a syringe or feed from the bottom again with a syringe, the process can be a pain Mike and patience is needed and plenty of lever pulling topped of by a quick un nip of nipple on the caliper to get the last bit of air out for an excellent brake..how did the fettle of headset go for hose ?? no slips I hope

[mikeallen]

Thanks for the Link, will have a good read of that.

No problems with the headset just took my time with a small file so it's as neat as a neat thing

Just need to get it all working now

[10 inch Terror]

I purchased a bleed tube from a German eBay seller, it makes it an easy job. Well worth the £10 I paid for it. Maybe do a search on eBay, he may still be on there. something like this

[nelson pk]

I've done 3 of these and never had to use a bleeding system.
1) fill your master cylinder with dot 4.
2) attach a tube to the bleed nipple on the caliper and put the tube into a container the other end.
3)open the bleed nipple 1/4 of a turn only and pull your lever in. DO NOT let the lever return as this will suck in air and you'll never bleed the system, keep it held to the handlebars and do the bleed screw up THEN let go.
4) repeat the process filling up the master cylinder as you go and never let the fluid run out in the master cylinder. Eventually you will feel pressure on the lever. Keep doing it until you get a nice, hard (ooh errr!) lever.

If this process doesn't work, something is leaking so check your hose connections etc.

Hope this helps!

[mikeallen]

I've done 3 of these and never had to use a bleeding system.
1) fill your master cylinder with dot 4.
2) attach a tube to the bleed nipple on the caliper and put the tube into a container the other end.
3)open the bleed nipple 1/4 of a turn only and pull your lever in. DO NOT let the lever return as this will suck in air and you'll never bleed the system, keep it held to the handlebars and do the bleed screw up THEN let go.
4) repeat the process filling up the master cylinder as you go and never let the fluid run out in the master cylinder. Eventually you will feel pressure on the lever. Keep doing it until you get a nice, hard (ooh errr!) lever.

If this process doesn't work, something is leaking so check your hose connections etc.

Hope this helps!

Thanks for this fella as it worked a treat jobs a good un

Not had chance to take it on the road yet but the slightest touch on the lever has the brakes on. Me thinks I'll have to be a bit light fingred on that lever out on the road

[nelson pk]

Glad i could help.

[cezeta]

remove the lever and pump the piston with a piece of dowel or paint brush handled. it allows the piston to pump properly