Hey! So I have this on going issue after a crash (My bike fell on the right side) where my front brake is dragging when I spin the wheel while my bike is on the stand. I've looked at other Vital MX posts on this topic, and nothing seems to be working. So far I've replaced the front brake line, and front pads. I've bleed the brake numerous times. The brake pad pin is completely free of debris and has been regreased. The front end is aligned perfectly. The wheel bearings are completely fine. The front brake rotor is perfectly straight. I made sure there isn't too mush fluid in the master cylinder. The caliper pistons look completely free of debris. The pin behind the front brake lever isn't bent. the only other thing I can possibly think of is that when I went down the brake lever pushed in too much to where it damaged something internally inside the master cylinder.
Thank you in advance!
Stock lever? Some aftermarket levers cause dragging. You may have damaged the mc. Is there any indication of physical damage on the outside of the mc that may have dented it inwards into the piston bore? This can actually happen from roost sometimes. Anyone remember Tomac a few years back had this happen from roost in a National. It might just need a simple rebuild. The lever jamming in hard and fast may have dislodged the piston seals.
I use an ARC brake lever (also tried stock lever). So I took the front brake lever, and piston assembly off, and it's still dragging. I checked the entire mc and there is no physical damage inside or out. The brake builds perfect pressure and the wheel stops on a dime when it spins for that half second. I just can't understand why the pads are rubbing so bad on the rotor. It's almost like the pads aren't retracting back to where they should. I might honestly just rebuild the caliper, and see what that does. This is really starting to piss me off.
Caliper bracket and or bolts bent?
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you got the wheel spacers on the correct sides?
Nope
Of course!
Are you spinning front wheel, slamming brakes on & holding lever, before tightening the pinchbolts? This centers the caliper on the disc….
Yes! The front end is perfectly aligned! When I spread the pads apart the wheel spins forever.
Fir sale: 24 Honda …new front brakes … barn find… I know what I got
What I've done to hunt down the component that's not allowing fluid to travel back to the master is do this:
1. Verify wheel not spinning correctly.
2. Crack bleeder (not holding brake on) - should see fluid come out if the system is holding pressure somewhere.
3. After pumping back up brake and verifying wheel is still not spinning correctly, crack the lower brake line banjo loose, observe if fluid comes out (when cracking the banjos don't hold the lever down since you are trying to see where the system is holding pressure itself).
4. Follow step 3 with the upper banjo if fluid came out of the lower. The system is failed in between where you are getting fluid and none.
5. If you still get fluid out of the upper banjo, then the master has failed somehow and isn't availing fluid back into itself or your lever combo isnt allowing the plunger to retract fully.
In my case I had a failed line that was acting like a check valve so when following the procedure above I would get fluid out of the lower banjo, but not the upper.
nicely done 👌
So I just followed your procedure, and here is what happened: when I cracked open the bleeder valve I did end up seeing fluid come out verifying that there is pressure. I then pumped the brake back up after closing the bleeder valve, and I opened the lower banjo bolt, and fluid did end up dripping out slowly, but I can’t tell if that’s just due to gravity or not. I then closed the lower banjo bolt and pumped the brake back up. I opened the upper banjo bolt and no fluid came out, however I did loose pressure in the brake lever when trying to pump it back up after re tightening the upper banjo bolt (I never pumped the brake when the bleeder screw or banjo bolts where open). So now I have to re-bleed the brake again unfortunately. Originally I thought the same thing about my brake line acting like a one-way check valve. That’s why I replaced the front brake line. So I pretty much got the same result as you, but I already have a brand new brake line.
So, I got around to rebuilding the caliper and here’s what I found. There was still debris from the old brake line inside of the caliper, and the caliper has pitting in it possibly from the debris (unless this is normal?) I attached an image to see what y’all think.
Glad to hear you found something! So it was just gravity and not pressurized fluid out of the lower banjo. I've got no feedback on the pitting. I don't recall seeing that, but it's been a while since I've had a caliper apart. It's not on the sealing surface, and it is just a cast part.
Did the caliper rebuild fix the issue?
I believe so, haven’t had much time to ride recently due to it being winter in the Midwest. Next time I ride I’ll lyk
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