Front brake problems

[AKMac]

Today I installed my wheels, and I seem to have a problem with the front brakes. The front brakes are dragging. It's possible to spin the wheel by hand, but it does not spin freely. Is this because I installed new brake pads? Or have I overlooked something when installing the wheel?

I know it's probably not the spooge hole because it was fine before, and I used a C-clamp to retract the piston to install the new pads.

Also it seems that rear might be dragging a tiny bit. I can spin it by hand, and it rotates for quite a while, but I can hear a little bit a scraping as it rotates.

[xschop]

thickness

what is the metric thickness of your rotors, are you refering to the ebc ones that u posted in pics?

[AKMac]

Yeah, it's EBC rotors and pads. The thickness is about 6mm.

I just removed the left caliper and noticed that the dragging is significantly less (it still makes a little noise with it removed though)

[TopCatGr58]

Hey AkMac,

You could have some corrosion or such built up around the the caliper piston, and even after you retracted it with the C-clamp, once you actuate the brakes, it may push back in towards the rotors, and not be able to retract easily due to same corrosion, etc.? The brakes are supposed to slightly drag, and your rear sounds fine if it can spin several times, then it's definitely not dragging enough to worry about!
T.C.

[mro]

Spinning wheels, got to go round

Did you follow proper wheel installation?

Before tightening the axle nut, right caliper is supposed to be tightened, left caliper left loose. Torque nut. Left side fork can be moved in/out to center caliper. Arrow on axle cap pointing forward and front nut tightened/torque first, then back nut.



mro

[AKMac]

The pistons looked pretty good. With a hard spin, the rear will go around a maybe once or twice. The front however will maybe move 4 or 5 inches before it stops. However, it doesn't seem that I did follow proper installation procedures.

Mro - I think your instructions are for a Standard model (I don't have axle caps.)

What's the proper way to put the front tire back on for a special?

[Ken Talbot]

By pressing the pistons into the calipers you would have forced a fairly significant flow of brake fluid back into the reservoir through the 'spooge hole'. It may have been okay before you started, but just that extra flow could easily have dislodged some old spooge and plugged the orifice.

Remove the reservoir cap and look into the bottom of the reservoir where the spooge hole is while gently pressing and releasing the brake handle. You should actually see a small fountain of fluid as the line pressure releases. If there is any dark colourization in that fluid, it is time for a flush. If you don't see the little fountain, it is time to poke a fine wire through the orifice to clean it, then do a flush.

[mro]

instructions are for a Standard model

yup, your right

Special ???
Don't have manual here.
(may have gone back to mexico, no green card)

Would look to see if calipers are centered tho.

Note what TC and Ken have said.
When I played w/my brakes other day(were working ok) found that bottom of pistons had rust, and what might have been brake fluid was a little thick en creamy. Disconnected brake lines and blew/flushed em out, same w/calipers. Emory cloth to the rust. Put in new fluid etc... Seems to be working. Rubber dust covers are shot, also toooo big to go back on, so need new ones.


mro

[AKMac]

Ok, I pulled of the cap, and seen a little fountain when I pressed the lever. It almost squirted out of the reservoir! Brake fluid is a light amber color.

Next I'm going to pull off both calipers to check for rust on the pistons.

Should I have mounted the calipers before installing the tire? My order was as follows: Install axle, Install calipers, tighten axle crown nut, tighten pinch bolt.

Here's a picture of the spacing. It's hard to tell from the pics, but it's about the same on both sides.

Man this sucks. I've been at this all day. This restoration has gone perfectly until now! I hate these brakes, and I have a feeling this is going to be something stupid when I find it.

Left:


Right:

[TopCatGr58]

Just a pinch should do it!

Hey AkMac,

Okay, now that the front axle and wheel and pinch bolt are all tight, loosen the caliper mounting bolt, and pivot the caliper a little, wiggle it to find the center of clearance, and then retighten. The caliper has that thick rubber O-ring next to the washer that keeps it in relative position, the calipers are supposed to be able to wiggle, turn a little under compression, the pre-positioning and tightening of them prior to tightening the axle/pinch bolts may have it just a tad too close to the rotor!?
T.C.

[LoserShoes]

Did ya remove and clean those little stainless steel clips that the pads ride on in the caliper? Could be all gunked up or deformed. May even need to be replaced.

Steve

[AKMac]

Well, I tried what you said topcat, but that didn't work. So I took the calipers apart, cleaned out all the gunk, made the pistons look like new, and reassembled them using new parts.

Now I can't get the brakes to bleed. I can see the little "fountain" but it takes about 3 or 4 pumps to get any brake pressure on the lever. Any suggestions?

[TopCatGr58]

Hey AkMac,

You've still got air in the lines, often trapped at that 1 to 2 junction! Remove the calipers, wedge something between the pads, and remove the hose where it's clamped behind the nameplate, and put them up on a box or such close to the height of the MC, or at least above the junction! Don't disconnect the hoses, just the clamp to the forks. Then repeat the bleeding process, occasionally tap that junction, and you should be able to get the rest of the air out of the lines, and then you'll have the proper handle squeeze/pressure!
T.C.

[xj11john]

bench bleed

I had the same thing happen when I had my calipers off, and also another time when I changed to ss lines.

when you disconnected the brake line air of course went into the system and you lost your prime in the master cylinder, take off the line at the master, place your finger over the hole where the line connects to the master, leave your finger loose enough that air can escape as you sqeeze the lever, some fluid will come out but concentrate on getting the air out with several pumps.

viola, you have a bench bled, primed master cylinder ready for the line to be connected back. Now go back to the bleeder screw on the caliper and bleed as normal.

Good luck, and looks like you're doing a fantastic job on your restore, keep at it.

[newmaac]

AKMac,
I was just checking out the brake post. I assume that it is working now?
Am I seeing a highly polished wheel stuck in between those rotors?

Have any other full bike pix to share?