Topic: Stuck front brake on a 72 K2

[Patrick]

Is your line attached to the caliper with a banjo bolt instead of the stock line? A standard banjo bolt is too long to properly tighten to a 750's caliper. I've done that, but I cut off a little of the banjo bolt to get it to screw in all the way.

[edwardmorris]

Is your line attached to the caliper with a banjo bolt instead of the stock line? A standard banjo bolt is too long to properly tighten to a 750's caliper. I've done that, but I cut off a little of the banjo bolt to get it to screw in all the way.

Its the stock line, albiet now that I'm looking at it up close, its slightly bent right where the free spinning bolt (caliper end) is. Is it possible its not all the way in eventhough the bolt is tightened? If so, how do I straighten this out? Old school hammar and anvil (gently of course)?

[edwardmorris]

Just read in the tips and tricks section for brakes, will using plumbing teflon tape really help stop the fluid from gushing out from the bleeder threads?

[ekpent]

Just read in the tips and tricks section for brakes, will using plumbing teflon tape really help stop the fluid from gushing out from the bleeder threads?

You should not need or want the tape if you are hooking everything up correctly and the parts you are using are safe for the road. So you were leaking in multiple areas is the actual blleder your problem area now. As for the lines at other connections they take 2 crush washers each,one on each side of the fitting. Really this stuff is usually pretty easy   

[edwardmorris]

Just read in the tips and tricks section for brakes, will using plumbing teflon tape really help stop the fluid from gushing out from the bleeder threads?

You should not need or want the tape if you are hooking everything up correctly and the parts you are using are safe for the road. So you were leaking in multiple areas is the actual blleder your problem area now. As for the lines at other connections they take 2 crush washers each,one on each side of the fitting. Really this stuff is usually pretty easy   

Yea, I agree, it wasn't too bad doing it my first time. It is still leaking in multiple places but I've had no luck finding any specific torque settings yet. The crush washer are there for the line, never saw them for the bleeder or the line end at the caliper. I will attempt to straighten out the metal portion of the line and retighten it as best as I can. Also, it may be possible that I'll need a new caliper seal because it seemed a little to crispy/hard for a rubber seal, and the piston was fighting it a little bit going back in. I just stumbled upon a this thread in the tips forum and just got wondering if ppl actually do that with the teflon tape

[edwardmorris]

OK, I just tightened everything by hand as hard as I could go without stripping the threads, not seeing any drips or leaks so far. Bled the brake properly and it is engaging. Only problem left now is that the lever is squeezing too far back and has a spongy feel. I made sure there were absolutely no bubbles. I can't tell how good the stopping distance is unless I can ride it, but I know that it is engaging and disengaging for now. Just have to figure out why the lever is going so far back and the spongy feel.

[Patrick]

Bleed your brakes again. If you have sealed all the leaks it should firm up the lever. Leaky brake lines leak air in as we'll as fluid out. With all the leaks you had it almost certainly needs bleeding. Spongy lever is the prime symptom.

Patrick

[RAFster122s]

Take a 1/2 in to 5/8 inch thick block and tape it to your handgrip so it prevents the MC from going all the way to the grip. Tape the grip firmly closed contacting the block and leave it overnight. The bubbles in the line can then come up to the MC and escape into the fluid reservoir.  You don't want to squeeze the brake lever so it goes past that wooden block when bleeding, otherwise the MC piston can travel past its design area and cause the seal in MC to be damaged, this then causes a slight leak at the MC. (Requiring MC to be rebuilt, which is probably a prudent move given the condition of the caliper.)

Might take a couple days for the bubbles to dissipate, sometimes it only takes a night left that way...

[ekpent]

Lightly tapping the caliper with a rubber mallet gets stuck air bubbles moving also.

[edwardmorris]

Take a 1/2 in to 5/8 inch thick block and tape it to your handgrip so it prevents the MC from going all the way to the grip. Tape the grip firmly closed contacting the block and leave it overnight. The bubbles in the line can then come up to the MC and escape into the fluid reservoir.  You don't want to squeeze the brake lever so it goes past that wooden block when bleeding, otherwise the MC piston can travel past its design area and cause the seal in MC to be damaged, this then causes a slight leak at the MC. (Requiring MC to be rebuilt, which is probably a prudent move given the condition of the caliper.)

Might take a couple days for the bubbles to dissipate, sometimes it only takes a night left that way...

I'm a little confused here, what exactly am I doing with a wooden block? Am I taping it to the grip, then pulling the brake lever and taping that squeezed up to the block and leaving it overnight?

[ekpent]

That was his suggestion but also leaving the block there while you pump to not over extend the master cylinder piston. Personally I have never made a leaker out of one without the block in place.

[edwardmorris]

Found the leak, its at the brake pad/piston itself, no longer in the line. I'll have to get back to this as my current priority is to keep the hm341 pipes from disintegrating into nothingness.