Special front brake bleeding

[xs650man]

Just fitted a new m/c (front ) new hoses, new copper washers, new bleeders. Bled the brakes and had a good firm lever. After about a week I noticed the fluid level had dropped and there was a small puddle on the ground under the right calliper. Stripped the callipers and re kitted them, put everything back together and tried to bleed it again but with no luck. Now if I clamp off both hoses close to the callipers I have a firm lever which points to air trapped in the callipers, no matter how much I bleed it I cant get results, tried cracking the banjos at the callipers with no luck. Could the new seals be bad ? Seems strange how I had a firm lever with the old seals ( that were leaking )

[IanDMacDonald]

Do exactly this and only this: get a plastic turkey syringe (gotta be plastic), and fit a clear piece of tubing on the end. Fit that over the bleeder valve. Push the fluid into the bleeder, slowly, holding tubing firmly onto the bleeder valve. Fluid will flow upto the caliper. Repeat for other side. Guaranteed results!

[xs650man]

Ok that sounds good, ill have to be careful not to push more air into the calliper aye ?

[IanDMacDonald]

When u reverse-bleed them, you push the air through the lines upto the M/C, and it vents to the M/C. Nothing works better.

[DGXSER]

Here is a method I use with great success, tried and true. Bleed as normal. Now, when you have a reasonably firm lever, tie the lever pulled back with brakes applied. Leave it tied like that for the night. Come back next day, you may find a nice firm brake.

[xs650man]

Do exactly this and only this: get a plastic turkey syringe (gotta be plastic), and fit a clear piece of tubing on the end. Fit that over the bleeder valve. Push the fluid into the bleeder, slowly, holding tubing firmly onto the bleeder valve. Fluid will flow upto the caliper. Repeat for other side. Guaranteed results!

Ok, just tried this Ian, but no luck,will try again but with an almost empty m/c, and let the reverse bleeding fill it it right up.

[IanDMacDonald]

Umm, doing this with a full M/C will have brake fluid everywhere after the already full M/C overfills . . .

[xs650man]

Umm, doing this with a full M/C will have brake fluid everywhere after the already full M/C overfills . . .

Na,starting with an almost EMPTY m/c Ian, Just gave it another go but no luck, even tried the opposite, sucking the fluid thru like one of those Mityvac's but to no avail.

[IanDMacDonald]

With all do respect, ur either doing it wrong, or your M/C is buggered.

[DGXSER]

Just to be sure, have you bench bled the MC? Meaning, remove the banjo from the MC, pump it with your finger over the hole. Bleed it like a caliper...finger over the hole tightly, squeeze the lever in, quickly release finger and return it pushing tightly, release lever. Repeat until fluid gets pushed out past your finger, watch your eyes, it can get you. Now, have the banjo in place on the line, with both crush washers in place. Quickly remove your finger and put the banjo bolt in and tighten it down.

Now you should get a decent lever pressure to bleed the calipers out with.

[xs650man]

M/C is new and air free, if I clamp the hose just after the m/c banjo the lever is rock solid, if I clamp the calliper lines just above the banjos, the lever is solid, its only when clamps are removed that I get a soggy lever which points to air trapped in the callipers eh...I tied the lever back overnight and it is a bit better, still half travel before its firm. Im pretty sure Im doing it right Ian, slowly pushing fluid in tru the bleeder untill the m/c is full, repeat other side, thread tape on bleeder screw so no air gets sucked in thru the threads.

[bikerphil]

Sometimes it helps to tap on the banjos/splitter/caliper with a wrench or small hammer, it can free up stuck air bubbles in the system and let them move on their way up to the resivior air space. Also, air bubbles can get trapped at the m/c banjo if it is sitting slightly higher than the resivior due to handlebar position. My 2¢, HTH.

[xs650man]

Sometimes it helps to tap on the banjos/splitter/caliper with a wrench or small hammer, it can free up stuck air bubbles in the system and let them move on their way up to the resivior air space. Also, air bubbles can get trapped at the m/c banjo if it is sitting slightly higher than the resivior due to handlebar position. My 2¢, HTH.

Yip tried all that, even unbolted m/c and mounted it higher on a stand

[bikerphil]

I got tired of my Special's crappy front brakes so I replaced the m/c with a coffin type Brembo, $125 new. This bike will stop on a dime now.

[Eveready1100]

Mate, please define

if I clamp the calliper lines just above the banjos, the lever is solid, its only when clamps are removed that I get a soggy lever which points to air trapped in the callipers

If you're doing what it sounds like you're doing, you are destroying the brake lines integrity and there'll be fluid flowing through the internal fractures in them.
Any chance of a photo to show how you are doing this??