Front Brake Issue

[timja1]

      This week I removed the front wheel, to replace the front tire. I put everything back together and pumped up the front brakes, lever felt normal. I went for a test ride and pulled the front brake lever and it went to the bar, no brakes. I pulled it again and had full brakes. So this is the problem I am having, lever pulled to brake, no front brake, pull it once more, full brakes. I removed the calipers and inspected to see if anything might be wrong with them, nothing I could see. Removed the front tire again, inspected and put everything back together, still the same issue. removed cap from reservoir, fluid is where it is suppose to be. I never cracked a line, so no fluid leaked. Regardless of whether the bike is running or not, same issue. seems like it might be an ABS problem, but not sure how that could have happened. I have removed a lot of wheels over the years, none with ABS though, and never had any issues. Any suggestions on fixing this issue would be greatly appreciated...... Thanks in Advance.... 

[koth442]

This is really odd. I would start by bleeding the brakes.

[timja1]

Yeah, that was what I was thinking to.

[2and3cylinders]

I've had a similar issue where I would pull the brake lever and I'd get little braking action, then add pull the lever again and have relatively normal braking.
 
 
I read bleed the front brakes and the rear as long as I was at it look for my post regarding this issue under my handle and you will see more expensive discussions in regard to this problem.
 
I'm going to be replacing the brake lines with stainless braided units this winter but this is not an easily explained or discoverable problem

[crempel]

I think you on the wrong track all together. Your problem is that in the process of changing the tire, someone bent one of the rotors. DAMHIK. Here's how to find out for sure. Take your calipers off and hang them from the bars with bungee cords to get them out of the way. Jack the front wheel off the ground and spin the front wheel with your hand. Eyeball along each rotor and you will quickly see the bent one. OEM can be had for $85 online. Buy new mounting bolts since the old ones are easy to chew up in the removal process. Easy fix.

[Guest kernowjim]

I think you on the wrong track all together. Your problem is that in the process of changing the tire, someone bent one of the rotors. DAMHIK. Here's how to find out for sure. Take your calipers off and hang them from the bars with bungee cords to get them out of the way. Jack the front wheel off the ground and spin the front wheel with your hand. Eyeball along each rotor and you will quickly see the bent one. OEM can be had for $85 online. Buy new mounting bolts since the old ones are easy to chew up in the removal process. Easy fix.

I was thinking something similar but it would have to be really bent to push the pistons back into the caliper to the point where there was no pressure at the lever.  Also, new discs are certainly more than $85, they're in the hundreds.  I'm going to guess that there is an issue around the ABS pump/valve 

[2and3cylinders]

I too thought the rotors were axial untrue and checked them on the bike utilizing a dial indicator but found them well within spec.
 
IMO certain 2015 and possibly latter units have an issue wit air leaking into the system but without fluid leakage. I suspect either the banjo fittings at the ABS distributor or the left caliper bleed valve.
 
Every 3~4k miles I've had to bleed the system.
 
I hate the feel of the system and went to Vesrah RJL pads which are HH+ versus the OEM GG pads, and besides braided lines also plan on trying the R6 or R1 MC.
 

[crempel]

I guarantee I’m right on this since I just did it this last Saturday, sadly. It’s such a easy thing to check in the method I described that not checking would be foolish. Always start with simple solutions. $85 plus shipping for the stock rotor. $2.04/each for the bolts.

[crempel]

[crempel]

I got in a rush and didn’t support the wheel with 2x4s when I went to break the bead. One push was all it took. Realized it the second I went for a ride. In his case the cost of being in a nutty was about $120. Could’ve been worse. New rotor installed and all is perfect again.

[pattonme]

a bent rotor will pulse - eg lightly apply/drag lever and you can definitely feel it.
 
> Every 3~4k miles I've had to bleed the system.
 
Something very wrong with that! Granted my KTM 525 does this but none of my other bikes ever have - I already know the MC and/or banjo seal on the KTM is questionable.
 

[betoney]

      This week I removed the front wheel, to replace the front tire. I put everything back together and pumped up the front brakes, lever felt normal. I went for a test ride and pulled the front brake lever and it went to the bar, no brakes. I pulled it again and had full brakes. 

I recently experienced the same issue, I got a new front tire installed and the front brake hasn’t felt the same since.  I use the R1 master cylinder so I am used to very firm lever pull, after remounting the wheel I can pull the lever almost to the bar.  The nice thing about the R1 unit is it has a bleed nipple on it, making it a snap to bleed as all the air bubbles rise to the top.  I went so far as to buy a rebuild kit for the master cylinder with no change, I then swapped out a brand new master cylinder, again with no change. I have bled and bled and re-bled the system, I even took it to the shop and had them hook up their compressor bleeder and they said they didn’t get any air bubbles out. 
At this point I am at a loss. 
@cremple I would think if the rotor was bent I would feel it. I have ridden bikes with bent or warped rotors and know exactly what that feel likes. The bike rides just like normal except the lever needs to be pulled almost to the bar to stop. But, I will take your advise and check the rotors anyways. 

[crempel]

I could not feel anything at the lever. Just sayin.

[pattonme]

All of this should be done with ignition OFF. You don't need ABS interfering in line pressure.
Work on one caliper at a time. I generally start with the one at the end of the chain.
 
pull the caliper off, pull the pads. squeeze the lever some to push the pistons past their normal position. clean the pistons where exposed. Shove them back all the way, all 4. Put a wood block in the newly cleaned caliper while you switch to the other. You may need to pull fluid out of the MC.
 
Re-install pads and caliper. pull on lever till both pad sets fully seat. It's not uncommon for one to seat while the other to "not quite get there". If this condition persists, you have a seal that is hung up and the piston isn't sliding. The o-ring is rotating and when pressure is removed it's "unrolling" and pulling the piston back a lot further than it should be.
 
Test braking with IGNITION OFF - just push your bike and make sure both sides are engaging. Test repeatedly to make sure they bite every time.
THEN try it with ignition ON and see if "no brakes on first pull" comes back. If so, something is wrong with ABS. A failed/bad/dirty sensor should NEVER result in the ABS pulling pressure out of the system but it's possible morons programmed the logic and in the event of an anomalous condition it fails OPEN instead of closed.
 
The front wheel sensor bracket needs to be mounted at the proper distance. Perhaps during the wheel change the cable got yanked on? Unfortunately I don't have a way to test signal pickup/continuity. The dealer can probably query the ECU to see what if any signal is being received when you spin the wheel by hand.

[betoney]

@pattonme. Thanks for the thorough procedure, I will test the calipers and see if anything is sticking.
 
Regarding keeping the ignition off to rule out the ABS, in my particular case the lever feel is both parked in the garage and while riding. Again, my lever felt perfect, I removed and replaced the wheel for new tires and the lever immediately had longer pull and felt weak.