front brake problem

[buellbolter]

So i had issue when i grab front back it was spongey and didnt have all its power. So i rebuilt master cylinder with one from americasportbike.com. i bleed brakes and now i can pull lever almost to grip. I dont have any air coming out and can see the fountain of fluid shooting out holes.. can anyone help me

 

[nicholas900]

Assuming you rebuilt it properly...Sounds like you still have air in the line.

Every one has a different way to bleed brakes. Here's how I do it.

-Get some clear tubing that slips tight over the bleeder.

-Get two bottles of brake fluid. (The second one could be a clean dry container filled with new brake fluid also)

-Put the box end of your wrench on the bleeder then slip on the tubing.

-Fill your reservoir and leave the cap off.

-Put the second bottle of brake fluid (or container of fluid) on the ground and run the clear tube into it so the end is submerged in brake fluid.

-Gently pull lever to stop and hold. Crack bleeder 1/4 turn or until you feel the pressure release. Only open it only far as you need to for fluid to flow.Tighten bleeder. Release lever. Check fluid level and add if needed.

Repeat

Repeat

Repeat

Keep doing this until you observe no air bubbles going into the second fluid can (container)

If you already bleed your brakes like this my apologies. But when you mentioned the fountain of fluid coming out I'm guessing you didn't. Good luck with it.

 

[buellbolter]

I will have to see about getting a hose tomorrow.

 

[ztied]

Good ideas above,my method
assuming master cylinder rebuilt right,and correct dot fluid
fill master cylinder
squeeze slow a few times,and hold.
crack open banjo bolt at master cylinder.(make sure you cover with a rag,and protect anything to keep fluid off)
Then close banjo bolt.
repeat a few times (usually 2 or 3 times will do it).you only have to lightly crack it open to release the air.
once you think you have the air out
move down to the caliper.
pump the brakes and hold
and crack open the bleeder on the caliper.
close the bleeder and repeat.
Make sure you are holding the lever in (like your applying the brakes) anytime you open a banjo bolt or bleeder.
if all goes well it should be working within a few minutes.
clean brake fluid off any paint,or plastic now
using a socket will help control the fluid from shooting everywhere, but will be a little harder seeing the bubbles.

 

[user_deleted]

the info provided above is excellent but let me add a few things here assuming you rebuilt the m/c correctly and are using either dot-3 or dot-4 fluid.....NOT dot-5:
1. you did not "bench bleed" the m/c so very large pocket of air is now trapped in your system.
2-connect clear plastic hose as mentioned above from bleeder nipple on caliper to appropriate container.
3-with m/c filled install cap and tighten.
4-feather pump the lever. this takes time but will build up small amount of pressure. feather pumping is multiple quick brisk pumps of the lever. do this approx. 20 times then rest for a few seconds. you will now feel pressure building up in the lever however slight. repeat and repeat.
5-as pressure builds and it will then proceed to bleed as instructed in posts above.

 

[go cytocis]

I concur with the recommendations above to be more intensive in bleeding.

Something I recall working years ago to remove a stubborn air pocket on an old Yamaha front brake was to perform the normal bleeding procedure with the caliper loose (with a wood shim similar in width to the disc between the pads) so that I could orient it facilitate evacuation of the air better.