Front caliper sticking when handle bars are turned left only

[Caleb R]

Hey everyone,
I'm having an issue on my 1979 Honda CM400T that maybe someone has heard/seen before because I'm a lose here.
When the bike is off, and in Natural, I can roll the bike forward/backward freely with the handle bars squared, and turned all the way to the right, but if I turn them to the left the caliper starts grabbing as if I'm squeezing the front break.... the hydraulic cable isn't being pulled/pinched either.
I have NO idea what would cause something like this. Also, it only seems to happen when the bike wheel is on the ground, if I use a lift to bring the front wheel off the ground and then turn it left and spin the wheel it spins just fine...

Thank you!

-Caleb

 

[LongDistanceRider]

Sounds like the wheel is shifting slightly under load. The would indicate a wheel bearing, bearing preload or axle torque being wrong.
Other possibility would be the caliper mounting to the bracket.

 

[Caleb R]

Thank you for the speedy reply! I will check those and report back!

 

[Caleb R]

Update: It's not the wheel, I removed the caliper and the problem goes away. I tried bleeding the break a few times and it still isn't fixing it. so I think I'm going to order a new rebuild kit for the caliper and break pads

 

[crazypj]

Check brake hose isn't catching on anything behind headlight.
It isn't the original hose is it?
Honda says change them at four years, almost no one ever does though.

 

[Alan F.]

I was thinking it could be the way the hose is failing internally from age.

 

[stl360+450]

Sounds like the wheel is shifting slightly under load. The would indicate a wheel bearing, bearing preload or axle torque being wrong.

Update: It's not the wheel, I removed the caliper and the problem goes away.

I'm not sure if you understood Jim's suggestion. I don't think he was suggesting that the wheel was causing drag directly, but rather that sloppy wheel bearings would allow the wheel and rotor to change angle with respect to the caliper and produce drag.

Removing the caliper would not be a good way to test for this condition.

 

[crazypj]

Picture of front end may be handy, something could be assembled wrong?
I'm sure I've seen this problem before on 250 and 400 but it would have been around 1979~80, done a lot of different bikes since then.

 

[Caleb R]

thank you all for the reply's, I will look into all these things over the weekend and check back in!

 

[Caleb R]

Reporting back, I bought a new piston seal, and o-rings for the shaft bolts between the calipers (each has two o-rings) along with new break pads and after replacing those and hooking everything back up it went away! I'm going to keep my eye on it though because I haven't taken it on any long rides yet. I'm not onto another issue which if I can't fix i'll make a new thread after reading through the forums and make sure it hasn't already been covered.

My guess is either the piston seal or the O-rings was the issue, I think the O-rings helped keep the caliper arm more aligned if that makes sense? and maybe not having any on the old shafts was enough to cause this issue when turning the handlebars left.