any tips/tricks? front brake bleed on abs ktm duke 250

[GPzPop]

google say just bleed caliper and mc like a non abs,

tried, using vacuum bleeder, but lever still soft.

strap to tie brake lever pulled in and leaving it overnight did not being joy

any hidden technique ?

 

[peterhively]

Was this just a routine bleed? Was the system full and working OK before you started? Or was the system dry, like a new brake hose or?

How soft is the lever now...are you building any pressure at all?

Sometimes a big bubble can get get stuck at the top banjo bolt...pumping the lever, and cracking loose that upper banjo can burp a big bubble and help things along.

 

[Busy Little Shop]

This cut away shows why the zipped tied lever trick failed to past air to the reservoir... whereas lever released allows a clear path back to the reservoir...



Try the reverse brake bleed technique...

 

[GPzPop]

Was this just a routine bleed? Was the system full and working OK before you started? Or was the system dry, like a new brake hose or?

How soft is the lever now...are you building any pressure at all?

Sometimes a big bubble can get get stuck at the top banjo bolt...pumping the lever, and cracking loose that upper banjo can burp a big bubble and help things along.

I am repairing crash damage (not crashed by me) where upon uprighting the bike, lever went to bar (amongst other issues)

lever is still soft after my attempt at vacuum bleed

I will look to do a burp of the mc banjo bolt
thanks for the guidance
- - S

 

[N4teTheGreat]

Maybe push the pistons back into their bore as well in case any air got trapped in there somehow. Reserve bleed should work too, though I have much to my shame, never managed to get it to work on any of my attempts. Also if you master has a bleed port don't forget that. On my Ducati which does have ABS I just bleed from the caliper furthest from the master first, then the other caliper, then the master. Also, sounds kinda silly, but I've had success on the DRZ getting a firm lever while bleeding in a parking lot by firing up the motor and riding around the lot giving the brakes a workout, I suspect the vibes from the motor along with squeezing and releasing the lever got the remaining trapped air to work it's way up into the reservoir. The internets were suggesting the banjo bolt trick on the DRZ too, but in my case the parking lot trick worked

 

[CDONA]

Tap the brake line along its length helps move bubbles,

 

[augustiron]

Tap the brake line along its length helps move bubbles,

That's great if the line just runs from the caliper to the master cylinder right above it,

but when there is an ABS unit likely under the seat, not so much.

 

[Lucytriple]

When you have the tool you can actuate the ABS unit to jiggle things about. When you leave it overnight with a zip-tied brake lever, don’t pull it all the way but rather just a bit so that the valve opens. I’m sure you already have the handlebars turned so the reservoir is at a highest spot or whatever loop in the brake line is at its highest spot. I do like tapping with something like a screwdriver starting from the bottom all the way back up to the top. It’s easier to actuate the rear out on the road but if you dare, get out and make the front actuate. Also not just vacuum bleeding, but manual bleeding as well. Another thing I like to do is just to lightly flick the brake lever, you know just the tip.

 

[Lucytriple]

Is it possible that the rotors are warped and the brake is going soft after you roll the bike around (and the pads get pushed out a bit?)