Topic: 500 - Front brake issue, next step? [Update: fixed]

[Chachi]

I did not disassemble and lube, but the bracket on the pin moves freely side-to-side by hand. The bracket stays taut against the adjuster screw (toward the RH controls) and the spring on the adjuster screw has good tension (when pushed toward the LH controls).

[bryanj]

When in the trade always stripped and cleaned as part of an annual service

[Chachi]

Hey bryanj - you mentioned cleaning the paint off from around the edge of the new pads... I got a set of Vesrah VD 102's in the mail today and sure enough the paint on pad A will not allow it to fit in the caliper body. What do you suggest I use to remove the paint from the pad edge? The pads did come with a nylon spacer/washer which I was missing.

[RAFster122s]

150 grit sandpaper works fine, just make it smooth so it slides in and out without catching. Dow grease, light coat can help here...

[Chachi]

Thanks. I have a repro caliper body on the way, so I'm going to wait and see how it fits that one before I sand.

[bryanj]

In shop use a wire wheel on a bench grinder, at home a bastard file(which is a grade of file!!)

[Chachi]

I finally have all of my parts/supplies. Note: the Vesrah VD 102 pads fit fine with the DSS repro caliper body - no need to sand paint off pad edges. I won't be able to assemble until tomorrow, but I wanted to confirm the piston orientation in the caliper. This is my first time doing this and I forgot which way the piston was oriented when I took it out last week. See the attached pic... that's the correct way, right? Just making sure before I reassemble.

[bryanj]

Yup

[Chachi]

I still can not get this thing sorted out and I need some more guidance.

What I've done:
-Replaced caliper body and piston with new DSS repros and new OEM seal
-Removed pivot pin, cleaned and lubed with Dow high vacuum grease and replaced o-rings with closest match from hardware store
-Lubed seal and piston with Wilwood brake assembly lube during assembly
-Purchased new pads (Vesrah VD 102) which included nylon spacer which I did not have before
-Purchased new OEM brake pipe for reassembly

Where I got stuck (Round 1):
-I could not get clearance on stationary pad (pad B, non-piston side)
-I was convinced the Vesrah pads were not to spec and were never going to fit
-The clearance was between pad face and disc, not the circumference of the pad due to paint
-Re-used my old pads (with the nylon spacer) as I knew they did at least fit
-Bled system

This went OK except I was still not satisfied with pad clearance and my lever was still quite spongy after bleed. I determined my clearance issue came from the lack of bend in my new brake pipe forcing caliper body B toward caliper body A and it was not the replacement pads depth. I disassembled everything and started over.

Where I'm stuck now (Round 2):
-I reassembled everything
-I messed up my replacement pad B, so I'm still using my original pads (with nylon spacer)
-I went heavy-handed on the bleed to get fluid to flow and continued to pump too hard/fast for bleeding after fluid reached caliper
-I didn't realize that even though I added a speedbleeder, I still needed to be mindful of technique
-I have let it sit overnight for three consecutive nights with gentle bleeding attempts during each day
-I gently bent the brake pipe with caliper attached to give more clearance to the stationary pad

I'm able to set my pad clearance now on the stationary pad using the adjustment screw and I am verifying clearance with an .006 inch feeler. I have been gently bleeding for over three days now and still have a rather soft lever. I took it out for a test ride tonight and I can stop OK, but not nearly as well as I could before I attempted the rebuild. Also, when grabbing the lever caliper body B visibly moves toward caliper body A (piston side). This does not seem correct and it did not happen before I added the gentle bend in the brake pipe during the second reassembly.

What do I from here? Keep letting it sit overnight and continue to gently bleed? I had a rock hard lever before, but I was not using the nylon spacer. Does the spacer result in a softer lever? Open to any and all suggestions. Definitely getting frustrated and burned out on this one.

[wowbagger]

are you still seeing air bubbles each time you bleed it?

[Chachi]

Over the last few days... if I let it sit overnight or for an hour or two, I can still get out a few bubbles after a few gentle pumps. However, when actively bleeding without waiting an hour or two or longer between attempts, the bubbles appear to cease after a few minutes of bleeding. So basically if I wait long enough, I can still get some out. Letting it sit tonight will be night #4. Up until tonight I've had the bleeder hose continually hooked up. The hose was submerged in fluid and when I was not actively trying to bleed, the speedbleeder was fully closed and cap was closed on MC. When bleeding, I am only cracking speedbleeder and leaving top off MC or on loosely.

[RAFster122s]

New pads will need to bed into the disk/rotor slowly to prevent glazing. Brake performance will improve after they are bedded/broken in.
 The spongy lever is sign of air. SS line or stock rubber brake hose?

[Chachi]

Re-using old pads for now. Will replace later once I can get things straight. SS lines. I agree lever feels like air, but going on day #5 of trying to bleed.

[RAFster122s]

Is MC rebuilt or new? A leak there pulling air into the fluid would never firm up.
Got any photos of your setup?

[Chachi]

The MC is new. It's also a DSS repro. It's been on for about two years and the SS lines have been on a little over six months. I've bled a few times in the past and haven't really had any problems. This is my first time using speedbleeder vs. stock bleeder valve. I use Prestone DOT 4 if that matters. I can add photos today.

[LesterPiglet]

I usually bleed mine with the caliper removed from the fork leg, compress the piston with a g-clamp so there isn't any trapped air. When you let it sit overnight you do have the brake lever pulled to the bars don't you?

[Chachi]

LesterPiglet... the first two nights I did tape lever closed (not all the way in, just firm), but then I read some mixed things on here about whether that makes a difference or not so I have not done that over the last few nights. I have also tried turning bars to the left overnight.

Latest:
-It sat over night (4th night now)
-Today hooked up bleeder hose, submerged end in fluid, opened MC cap and put back on loosely, cracked speedbleeder
-Gently bled for approx 10-15 minutes with sets of 4 slow pumps with pauses in between, got out a few bubbles
-Stopped getting bubbles and was able to pump 4 slow pumps with 15-20 sec pauses in between with no bubbles
-Was able to do that 5 times in a row for a total of 20 pumps and no bubbles
-Let it sit 5 minutes, repeated the total of 20 pumps (5 sets of 4 with pause) and again no bubbles
-Let is sit 30 minutes, repeated same process with same result

But, the lever still feels spongy. It is not as firm as it used to be. Again, in addition to the rebuild, I've added the nylon spacer/washer. From what I can tell, pad clearance is in spec (.006 feeler on each side) and caliper seems to be working properly.

[Chachi]

RAFster122S here are some pics...

[Chachi]

RAFster122S here are some more pics...

[LesterPiglet]

That bottom picture. Your pads are knackered. You'll never get sorted with those installed. The pads will be trying to distort the disc which is giving you the spongy feel.
Take the caliper off, bleed it like I said in my last post then install new pads. Re-attach the caliper, set your static pad clearance and pump the pad out to it's operating position. Make sure your MC doesn't run low on fluid during this final stage.

[thep1pe]

RAFster122S here are some more pics...

There is something seriously wrong with your brake pad/disk orintation. The pads are wearing at an angle and don't seem to be clamping the whole area of the disk. Have you got the right disk on there and are you sure the swing arm is squared up. Maybe a bent arm.

[thep1pe]

Just looked at my bike. You have the the fender mounted behind the swing arm. It should be at the bolt heads. That's what is wearing the pads at an angle.

[LesterPiglet]

Just looked at my bike. You have the the fender mounted behind the swing arm. It should be at the bolt heads. That's what is wearing the pads at an angle.

I just looked at my bike and it's the same as Chachis!  I've just installed replacement forks yesterday.
Thep1pe is correct though.......must sort mine tomorrow.

[Chachi]

thep1pe... Can you share a pic of yours?

[LesterPiglet]

There is a photo in the Haynes manual if you have one.