Front break drag

Howdy.

My front brake recently started dragging on the rotor and I'm not sure whats causing it.

For a couple years I've had the newer style floating rotor, stainless lines and organic pads fromLen and had no problems. Recently it started to drag and its bad enough that its somewhat difficult to push the bike in neutral, and when rolling I can audibly hear the pads dragging on the rotor.

I did recently install a new moto style handlebar to replace the factory buck horns, and the brake hose routing near the bar is less ideal than it was, but no kinks, or anything like that. I don't really think moving the bars around should cause the caliper to start dragging anyway, but cant hurt to mention it.

Maybe I just need to remove & reinstall the ft wheel and or caliper to get things re-centered.. but looking for advice before digging too deep.

Advice? Suggestions?

Thanks

 

Was your master cylinder rebuilt? There is a very very tiny hole from the piston bore to the reservoir that allow the pressure to bleed off once you release the lever. Those get plugged up easily therefore causing your drag.

If not rebuilt, I suggest getting a kit from chacal and doing the MC and caliper if needed.

 

Yes, the MC and caliper were completely rebuilt at the same time I installed the floating rotor & stainless lines.

The lever action is good and provides strong braking. Its just that when the lever is released, some parasite drag remains - which is a new development, sometime after installing the new handlebar.

The main deal is I can hear it rubbing as i drive and its really annoying. No opposed to re-re-building, etc, but will examine all other angles first.

Thanks

 

Did you Mae sure that bypass passage is clear? There are two passages into the piston bore.

 

Wondering if the handle bar/ brake line rerouting scenario is restricting flow. No problem braking, but since the return is dependent on the very small orifice, could a small restriction in flow (tighter angle on a brake line) be enough to cause the caliper not to release fully?

 

the angle on the brake line isnt severe enough to cause restriction. The hose is still round/circular throughout its length. No kinks no pinch, etc.

Does anyone have a photo of said master cylinder "bypass passage"?

My thoughts are that its not blocked, since the system was spotless after being rebuilt. No contaminants in the system should mean no potential blockages.. Perfectly willing to take a look, though if doing so requires re-bleeding the brake, I'll probably try a few different angles first....

Maybe my left fork lower is twisted slightly and is not orthagonal to the rotor?

Thanks again guys

 

fsm suggests rebuilding the calipers every 2 or 3 years as well as the mc

I would start with the calipers

when yoou look into the mc fluid resevior there are 2 holes on the bottom
one is very small you should see fluid come up when you squeeze and release the brake lever

 

When was the last time you changed the brake fluid? It should be an annual event. As the brake fluid absorbs water, some of the fluid gels, and then becomes a crusty blob that can find its way to block flow, thereby causing brake drag. Another culprit can be corrosion on the caliper pins, or the pad retaining pin.

 

Not a brake expert, but can the problem be isolated by cracking open the bleeder valve on the caliper? If the brakes free up when cracking the valve open, then look for an issue with the hydraulic fluid flow, such as the return hole in the master cylinder or partially restricted lines.

If they still drag excessively after cracking open the bleeder valve, then look for a mechanical issue such as k-moe suggested with the caliper pins or the pad retaining pins. Maybe add to the mechanical list the seal groove and was it meticulously cleaned when the caliper was rebuilt.

 

That is spot on advice for troubleshooting this issue. I would just add that you should pump the lever a few times before pushing it around the garage to build up some pressure. If it drags then crack the bleeder and see if the dragging goes away.

 

I went to try the bleeder trick and figured out that the spedo cable was hanging up on the caliper every time I got off the bike (when the suspension would top out), knocking the caliper out of alignment.. a few adjustments of the spedo cable routing and a few wiggles of the caliper and im back in business w/ little to no drag.

Much simpler solution than I expected...

Not really a fan of the floating caliper design, but it is what it is. Marking this as SOLVED..

Thanks for the tips!

 

does your speedo cable need to be longer there are add on cables.


HCP17702 Aftermarket drive cable EXTENDER CABLE, extends the length of your stock speedometer or tachometer drive cable (at the gauge end) by 6", just the thing when using modified handlebars or re-located gauges! Saves you the expense of having to buy a completely new drive cable. Correct end fittings allows you to screw this cable "in-between" the end of your current cable and the gauge head fitting.
$ 16.95

also comes in 8 and 10 "

are you using the cable guide?

 

Mine did that too, I found two things helped resolve the dragging.
1. I rebuilt the caliper and polished the rust and calcification from the puck and caliper inner surfaces
2. I cleared the return hole in the master cylinder by using a "C" clamp to forcefully retract the puck into the caliper (after filling with fluid) this forces fluid through the potential plugged passageway.

The most likely culprit is the puck's chromium finish is deteriorating (pitting) and the pits are dragging on the internal o-ring. If the puck plating is severely pitted buy a new one, new gaskets and maybe rebuild the master cylinder too, they get full of gunk due to condensing moisture and environmental reaction (oxidation).

 

I just started having this same issue. Fluid comes up when I squeeze the handle but not when I release it....

 

Is this with good clear fluid you are having these issues? Normally the master is not plugged once it is cleaned and has clear fluid, but then again anything and can happen with our older bikes. I use a hair from a steel brush to make sure the "return" or upper MC hole is open. What out if you are unplugging it for the first time, it could be under pressure. Just wear eye protection and cover up any paint that might get hit.

As for the calipers and the pucks, it is a great idea to brake them all the way down and clean them out. The oil brown brake fluid will get suck in there and not flush out all the way with just a flushing. Some people use a grease gun to push the puck out or low pressure air. Just make sure you hand and or fingers are out of the way of the puck, you will be hurting if you get bit by it when it comes out.

 

Couple years ago I rebuilt the caliper, got a new master cylinder and new steel lines.
First of all, maybe I am an old timer but what the heck are the pucks?

 

puck is the caliper piston

 

Fair enough, well then it might be that there is some build up of dirt or other stuff in the calipers. Subaru had a problem with their Forester line on the back calipers, the tolerance for the brake shoes in the calipers were so tight that the shoes would not release from the disk. That could be the issue here, check to see if the pads are lose in the calipers, if not a file or little angle grinder will be needed to loosen them up.

If there is no pressure on the line then it would have to be something to do with the caliper, piston or how tight the pads are in the calipers.

 

Yamaha does want the brake system rebuilt every 4 years.