Can't refit front caliper after wheel removal

GraemeH

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I took my wheels off to get them cleaned up. Took both disks off too. Now I can't get one of the calipers back on - just not enough clearance.

Logically I would think the disk is not fully flush and tightened to the hub but it certainly appears to be. What else could be an issue here?

20230602_123510.jpg


20230602_123528.jpg
 
Take a large screw driver and wedge the pads apart, you may have accidently bumped the brake lever a bit preventing the caliper to go on. Once on you can pump the lever a couple times and it will recenter
And if the pads don't move fairly easy there could be a problem with a small hole in the master cylinder that can get plugged.
 
Can't be sure from the pics, but I'd guess it's just that the pads/piston shifted a bit. As RC4MAN said; pry 'em back apart: firm and slow on the pry - you're pushing fluid back up to the master cyl.
 
I did manage to force the caliper on but the housing is hard against the disk so pumping the brake lever didn't help that.
I did take the wheel to a garage for cleaning and they removed the bearings. I am wondering if they omitted to replace all parts...
 
The disks normally sit directly onto a flange on the hub so it is unlikely that fitting the wheel bearing would have anything to do with the problem.
Does the wheel turn freely without the calliper attached and do the disks run true?

Forcing won't help. Did you try to push the pads back as suggested?
If they won't go back (you may need a little effort but not too much) then you need to investigate the reason for this.
Have you done any work to the m/c?
Check that the m/c piston fully returns to its normal resting position and that the bleed-back hole is clear.
If OK you will need to remove the pads and inspect the pistons for a build up of crud (clean off) or corrosion which may clean..or not.
 
Pic of caliper assy. aligned with rotor (perhaps both sides)??
 
I believe I'd be inclined to mount the calipers to the forks and then fit the wheels and rotors to them, flat blade screwdriver to spread the pads apart.
Is it possible that the rotors were switched side to side and that the pad wear is now off a wee bit? Possible.
 
loosen axle clamp bolts. Install caliper, it should go easy.
This might be a good time to do;
Would prolly be best to loosen the fender bolts for the tube test.
 
I fixed it, mostly... The semi-circular cap at the bottom of the left hand fork has an arrow on it which I hadn't noticed and assume is supposed to point forward. Changing this and following advice on another thread to tighten the crown nut before tightening the fork bottom nuts gave me a mm more space.

So calliper is on though I still think it is not as nicely aligned with the rotor as the right hand one. There is also a slight friction as the wheel is not completely free and will stop spinning after one revolution.
 

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Did you tighten the axle clamp at the bottom of the LH fork slider before tightening the axle nut? If so, loosen the axle clamp and pump the fork a few times, before tightening it again.
 
Yes, that axle clamp on the left fork leg gets installed a certain way. Yes, the arrow on it's bottom should point forward but there's also a specific way the nuts should be tightened. If you look closely at the axle clamp, you'll notice the front section is thicker than the rear. It should be tightened or at least just snugged up 1st until it touches the fork leg. Then you tighten the rear nut. You want to end up with no space between the clamp and fork leg at the front, and a small space at the rear .....

Axle Clamp.jpg


Any time you encounter a clamp with an arrow on it like this, this is the usual install procedure. The stock front MC uses a similar set-up .....

MCClamp.jpg


And yes, the correct procedure for installing the front wheel is to tighten the axle, at least most of the way, while the axle clamp on the bottom of the left leg is still loose. Use a bar of some sort through the hole in the axle to keep it from spinning. Then before you tighten the clamp, pump the forks several times. This will centralize and center the left leg on the axle. Sometimes tightening the axle causes it to catch on the left leg and pull it inward. That may be what's happened in your case. You can even loosen that bottom clamp and pull out on the fork leg to see if that will center the brake disc better. Also, if your fender isn't a nice, slip fit between the forks, that can throw their alignment off. In your case, the fender mounts may be loose between the forks and tightening them down is pulling the left fork leg in a little. I would loosen the fender before doing the fork pumping and wheel centering, tightening it back up after the axle and axle clamp have been tightened.
 
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