dragging front brake

[deedub]

My front brakes are dragging hard, so hard that I've decided to stop using the bike until I get it solved, but I can't figure out what's going on.

Starting a couple weeks ago, something felt wrong with the front wheel while riding. Since a rear wheel bearing had failed recently, I thought I was having the same problem with the front bearings. But it turns out to be the brake - the pads are dragging on the rotor, because they're held so tightly between the pad retaining pin and the pad clip that they jam in place and won't let up off the rotor. The caliper and caliper bracket fit together correctly and slide freely, the pistons are clean and move freely, and the pad retaining pin threads cleanly without the pads installed, but with the pads in place and that little pad clip in place, it takes way too much force to push the pads down to align the holes with the retaining pin, and they stick tightly in place once the pin is through. I don't understand why it's happening, what caused it to start now after 40K miles, or how to fix it short of just throwing parts at it. I replaced the pads and pad clip to no effect, but haven't changed anything else yet.

Does anyone have any ideas? Experienced this before? I'm considering buying a whole new (used) caliper assembly off ebay if I can't figure out what's wrong with mine.

 

[Beemerphile]

It should not take much force to push the pads down to align the holes for the retaining pin. Is the pad clip seated completely into the caliper body?

BTW, if yours is the 2-pot caliper (manual transmission) I have a used take-off caliper that you can try.

Lee

 

[deedub]

Yeah, there's something wrong, but I can't figure out what. The clip is seated correctly (I believe), and it's a new clip too. Something must be misaligned to make the pads jam against the pin, but I can't figure out what. Here's a pic showing the clip/pad/pin problem area. Edit: Yes, I have a manual trans 2012 with the 2 piston caliper.

 

[Beemerphile]

I don't see anything wrong from that picture. Would you like me to send you my spare caliper to either use it or compare it to yours to see what is different? If so, PM your address.

Lee

 

[deedub]

Thanks, that's very generous of you. Let me take another crack at it tonight and triple check that it isn't something simple/stupid on my part before troubling you.

 

[dduelin]

I seem to recall the service manual warns against inserting the retaining clip at the top end upside down or backwards as it fits both ways. Do you have a service manual to check for proper assembly?

 

[deedub]

You mean the other clip, the one that mounts the other end of the pad into the caliper bracket? I've got a non-Helm service manual, but it doesn't go into enough detail to show that clip. I didn't mess with that clip so it's worth a look, I'll see if flipping it fixes the alignment of the pad.

 

[dduelin]

I got a look at mine a minute ago and took these pics. The bronze colored retaining clip can be reversed but I'm not sure how it would affect the pads fitting into place. If the pads are correct for the bike the only thing that can be wrong is that the end of the pad(s) are not inserted all the way into the notch at the upper end of the caliper.

Left side looking through the wheel to the left side of the caliper:


Right side looking left:

 

[deedub]

Mine looks the same, so unfortunately that's not it. I think there's only one way to insert that clip - if it was turned around the rotor wouldn't be able to pass through the gap in it. Speaking of the rotor, I'm going to have to replace that too - there's a channel getting ground into it by the pads dragging.

 

[TigerDude]

any chance there's something wrong with the front wheel bearing & the wheel isn't square?

 

[SergeantChuck]

This might sound like a stupid comment so take it for what its worth. Lets say your applying the front brake which should push the pads against the disc evenly and then you release the brake. The desired affect would be that the pads retracts. Maybe the lower end of the pad were the hole is located that slides through the retaining pin is so gummed up and dirty is it not allowing the bottom edge of the pad to slide back.

If you feel comfortable you could remove the pads and see where you getting extra wear which should help you determine wear the pad is getting stuck. Maybe not. Just an idea. I would take it all apart and clean the two clips, the retaining pin, and the area on the pad where the pin sides through the pad.

 

[DirtFlier]

Just out of curiosity, have you ever replaced the brake fluid and cleaned the inside of the master cyl reservoir?

There is a tiny hole in the bottom of the reservoir that allows brake fluid to return after you release the lever or pedal. If that hole becomes blocked with crud, it will not allow the brakes to release. Your bike is fairly new so I would assume this isn't a problem but stranger things have happened.

I change brake fluid & bleed the system every two years and always clean that area carefully to avoid problems.

 

[TN Thunder]

I just recently had a similar issue with my Valkyrie rear brake. It was wearing one end of the pad more than the other. Ordered new pads, put on new rear tire and cleaned the pushrods of the calliper. Seems one had a little crud on it and wouldn't let it go all the way back after braking. You may have to pull the calliper and clean the pushrods. Only other thing, and I don't know if they have it or not, is the pressure relief valve sticking so once the fluid is sent to the calliper it can't return to the master cylinder.

 

[deedub]

any chance there's something wrong with the front wheel bearing & the wheel isn't square?

No, I don't think so. The wheel bearing was my first assumption because I just had a bad one on the back, but the wheel spins cleanly with the pads out of the way.

Just out of curiosity, have you ever replaced the brake fluid and cleaned the inside of the master cyl reservoir?

I've bled and replaced the fluid a couple times since new, though I've never cleaned the reservoir out.

I would take it all apart and clean the two clips, the retaining pin, and the area on the pad where the pin sides through the pad.

Since discovering this problem I've cleaned & lubed everything, and replaced the pads and the clip, but not the pin. Beemerphile is sending me his old caliper to try out. That'll help me figure out if the problem is with my caliper or somewhere else (wheel, rotor, reservoir, or my head).

Did you replace the brake pads with the exact same make/brand of pads again?

I had aftermarket pads on when I noticed the problem, and replaced them with OEMs, which didn't make any difference.

 

[Garnet]

Do the brakes free up when you crack the bleeder? That would indicate a hydraulic lock upstream of the caliper.

Old brake hoses can delaminate and turn into a one way valve. This is quite common but usually on 10 or 15 year old hoses.

 

[TN Thunder]

Check the calliper push rods. If they are crudy they will cause the pad to stay on surface longer or permanently if really bad. Next check is to see if the return valve is hanging so that he fluid once actuated is not allowed back to the reservoir. I'm not that familiar with the 700 yet and it may not have such a valve but these two things can cause the brake pads to stay out once pressed. I had a similar problem on my Honda Valkyrie, dirty push rods.