Front Caliper Adjustment?

[jelo]

Finally got to ride on Thursday after almost six months of not. Anyways, one of the last things I had done back in September was the 24,000 mile service at the dealership. Not sure what all brake stuff gets done then but I'm now getting a little scraping sound in the front brake, nothing from the rear though. If I manually open the space between the pads in the front caliper and spin the wheel - no noise. Squeeze the brake lever enough until it grabs, and then let off, spin the wheel light intermittent scraping sound. Can't tell if it's the inner pad, outer pad or both. Is there something that adjusts the caliper position side-to-side so I can center the drawn open 'resting' mode over the brake rotor? Or could it be that the caliper is not opening enough when I let off the brakes? I can see how all the pieces go together in the assembly drawing, but I've never messed with brakes before. Thoughts?

 

[670cc]

There are no adjustments. The pistons self retract a small amount due to the shape of the seals. The caliper self centers. About the only thing you can do is inspect the pads and lube the pins. A slight amount of rubbing is normal. Since your rubbing/scraping sound is intermittent as the wheel rotates, that indicates the rotor may be slightly warped or worn unevenly. There are specs in the manual for runout and minimum thickness.

I wouldn't worry about it unless you are hearing loud scraping or feeling significant pulsing when applying the brake.

 

[OriginalRocket]

how was short term storage? Did anyone or anything hit, or lay on the disk brake?

 

[jelo]

Thanks for the thoughts - No pulsing - I know that would mean something's up. Though high mileage on the bike, it's been lots of open road not city traffic, so not heavy brake usage.

 

[jelo]

how was short term storage? Did anyone or anything hit, or lay on the disk brake?

Storage involved clearing out a corner in my garage where it spent the winter. Live by myself so I know nothing happened to it. Worse than normal winter here so just didn't get to ride.

 

[jelo]

Alright - through a few conversations, I've been quickly educated on how disc brakes are supposed to work. Best I can tell the caliper isn't 'floating' like it should, and there's a squeak if I try to slide it from side to side with the pads opened up - seems like it's not lubed adequately or maybe some corrosion on the pins where it should slide.

 

[Lou Wambsganss]

The caliper is easy to take off. Use a good disc brake grease and lube the pins, sliders, etc. Since you report the noise as intermittent, can you use a marker and try to pinpoint the spot on the rotor that is causing the noise. If the bike sat for 6 months, the spot where the pads sat on the rotor could cave corroded due to humidity and temperature changes. Being stainless steel, whatever surface corrosion may be present should be fairly easy to clean up with scotch-brite. It should also go away as you drive.

 

[jelo]

The caliper is easy to take off. Use a good disc brake grease and lube the pins, sliders, etc. Since you report the noise as intermittent, can you use a marker and try to pinpoint the spot on the rotor that is causing the noise. If the bike sat for 6 months, the spot where the pads sat on the rotor could cave corroded due to humidity and temperature changes. Being stainless steel, whatever surface corrosion may be present should be fairly easy to clean up with scotch-brite. It should also go away as you drive.

Thanks for the info and ideas - Unbolted the caliper, pulled back pin, removed pads, then scrubbed with tooth brush and hot soapy water.
Dealer had apparently dinged pads with rotor when reinstalling wheel at some point, took a file and smoothed out the rough edges.
Dealer also has a habit of taking pressure washer to everything before it goes out the door and the bugs just get so bad out here
so I'm thinking it'd be good idea to lube pins and sliders, possibly caliper outer dust seals?
Any brands/products suggested for this type of thing? Something high-temp to lube pins and sliders I'd guess?,
and somebody mentioned silicone grease for dust seals? Not familiar with using disc brake grease, what do I need to know there?
There's ~2.5mm of pad remaining on fronts (~5mm left on rears) - thinking I've gone through 1/2 - 2/3rds of front pads in 25,000 miles.
Would it be worth it to just start with a fresh set of pads, and maybe springs, for the new riding season? - seems cheap enough $40-$45?

 

[L.B.S.]

IMHO, one thing that many people forget or are unaware of, is the longer you go with almost used up pads, and try to use up that last millimetre of material, is that the piston/s is/are pushed further out of the caliper and can possibly get more crud and moisture etc., around the seal area. Then when you push it back for thick new pads, the seal can get damaged by the rough surface, and it only gets worse from there.

Not saying that's what you are doing of course, but just thought I'd mention it as an observation of mine over the years, and having gone through more than my fair share of used bike seized caliper pistons, gunked up seals, pitted bores, and non-slidy pad sliding pins, lol.

I don't change the brake fluid with a rabid frequency, but I do often inspect and make sure the moving parts of the calipers are in good order, and free to do their bit without binding or catching up on stuff. Less is more when it comes to lube though, I wouldn't go crazy with it. It has a miraculous way of going where you don't want it to.

 

[dduelin]

Thanks for the info and ideas - Unbolted the caliper, pulled back pin, removed pads, then scrubbed with tooth brush and hot soapy water.
Dealer had apparently dinged pads with rotor when reinstalling wheel at some point, took a file and smoothed out the rough edges.
Dealer also has a habit of taking pressure washer to everything before it goes out the door and the bugs just get so bad out here
so I'm thinking it'd be good idea to lube pins and sliders, possibly caliper outer dust seals?
Any brands/products suggested for this type of thing? Something high-temp to lube pins and sliders I'd guess?,
and somebody mentioned silicone grease for dust seals? Not familiar with using disc brake grease, what do I need to know there?
There's ~2.5mm of pad remaining on fronts (~5mm left on rears) - thinking I've gone through 1/2 - 2/3rds of front pads in 25,000 miles.
Would it be worth it to just start with a fresh set of pads, and maybe springs, for the new riding season? - seems cheap enough $40-$45?

Auto parts stores usually sell small amounts of brake grease in one or two use packages. It's silicone based to use on rubber seals and boots because some petroleum based greases swell rubber parts. Brake grease will be high enough temperature for the application. Pads are cheap enough to replace but the wear indicator is set at 1mm material remaining. 2.5mm left is about half the pad life. That's your decision. Nothing else should need replacing at such low mileage. If you take the caliper off to clean the pistons do not use "brake cleaner" but rather just use clean new brake fluid and bits of cloth or an old toothbrush. If the dealer used a power washer I think I'd pull the caliper off the sliding pins and clean the pins and the bores the caliper slides on. Getting moisture and corrosion in/ on those can cause stickiness and the scraping sound you had. This is a common problem with low tech slide pin calipers.

 

[Harald]

IMHO, one thing that many people forget or are unaware of, is the longer you go with almost used up pads, and try to use up that last millimetre of material, is that the piston/s is/are pushed further out of the caliper and can possibly get more crud and moisture etc., around the seal area. Then when you push it back for thick new pads, the seal can get damaged by the rough surface, and it only gets worse from there.

A little tip for your caliper seals. Before pushing the pistons back in the bore of the caliper, clean them throroughly so you don't force crud into the seals. Get a piece of material that's as thick as the rotor and both brake pad backing metal (wood shims work fine). With the caliper in hand, place this piece of material between the pistons and apply the brake to force the pistons out further. Now take a toothbrush and a cleaner like Simple Green and scrub the caliper clean, with special emphasis on the exposed pistons. Rinse thoroughly and then push the pistons back into their bores.

This will greatly increase caliper seal life and prevent dragging brakes.