After a lot of work and money...it's official--no front brake at all

[chuck hahn]

Tell him to hurry the hell up already...OH the suspense is too much!!!!!

[bwringer]

Sorry to keep y'all in suspense!

Basically, the caliper piston was hanging up. The piston would extend, but there was so much seal drag that the seal would pull it back way too far. So you'd use up most of the master cylinder travel pushing the piston back out where it should be. In other words, the new seal was ever so slightly too big.

I first tested the master cylinder by disconnecting the caliper and then holding the banjo fitting between two fingers. When I pulled the lever, fluid started coming out immediately, so I knew the master was good.

Everything looked nice and clean in the caliper, but even without the seals installed, there was a lot of drag between the piston and caliper. I polished up the caliper bore and the piston a bit more with a Scotchbrite pad until I got a nice slip fit (this is where it helps to have done this several other times -- you know what it's supposed to feel like).

After re-assembling with the seals, there was WAY too much drag -- it was possible to get the piston installed, but I had to clamp the caliper in a vice and use a big lever to push the piston in. I was hoping it would loosen up a bit, but after several in and out cycles it wasn't getting any better. A caliper piston should pop in with pressure from two hands. I could get it to move out with air pressure, but the seal drag would still pull the piston back way too much.

So here's where it may get a bit controversial for some... I basically "polished" the seal with another Scotchbrite pad soaked in brake fluid. That's right, I used a Scotchbrite pad on the seal to remove juuuuuuuust enough rubber to make the thing work correctly. No hard scrubbing -- just around and around and around and around, being very gentle and keeping things soaked with brake fluid.

After a thorough wipe down with clean towels and a rinse in a bit more brake fluid, I reinstalled the seal to check the fit.

It took about three rounds of this seal polishing, but the piston finally popped in like it's supposed to. I buttoned it up, it bled out easily, and took a test ride -- it works great! No binding or leaks.

I tested the system with a LOT of pressure, and bungeed the lever back for about half an hour, and there were no leaks. Joel apparently survived the ride home, so that's good...

No, you shouldn't attack tight seals with sandpaper as a regular thing, but in this case an unusual solution was needed.

[barnbiketom]

Very good!

[chuck hahn]

Well that solves it. I was thinking initially the seal was pinching from crud behind it reducing the working ID a bit..I was close!!!

[bwringer]

Just to be clear, oldrookie did all the right things -- the caliper was absolutely immaculate inside, and the piston had no corrosion or pitting at all.

[chuck hahn]

I have no doubt..we all mentioned ALL the basic culprits it could have been. Was this an OEM seal or from an after market source. May be of value if it was after market and not a good seal to avoid buying!!!

[oldrookie]

The seals were Suzuki OEM seals. I purchased them from Boulevard Suzuki. The first was purchased last spring and the other was purchased just a few weeks ago.

Bought the second once I had narrowed the possible suspect down to the caliper instead of the master cylinder.

[Agemax]

HOORAY.........glad its all sorted now and certainly a tip to remember in the future

[john82q]

I just rewatched oldrookies video he posted previous.

http://i291.photobucket.com/albums/ll288/oldrookie_2008/20121109_071657.mp4

Its so obvious whats happening now...yet no one tweaked at the time.

OEM or not matters swat if it dont fit proper. Goes to show, you can muck around on the internet all you like but you cant beat hands on.

[oldrookie]

Well, can't beat knowledgable hands-on. Had me beat until Brian stepped in.

[tbrand69]

The seals were Suzuki OEM seals. I purchased them from Boulevard Suzuki. The first was purchased last spring and the other was purchased just a few weeks ago.

Bought the second once I had narrowed the possible suspect down to the caliper instead of the master cylinder.

This is good news for me. I also bought a new seal from them a few weeks ago. I've been sick and haven't had a chance to mess with the caliper seal yet, but that's what I was thinking. That piston is really tight.

Looks like a cure for Old Rookie Syndrome has been found. Yay!

[oldrookie]

I'm still squeezing the brake every time I walk through the garage. Hard to believe this long national nightmare is over. (I might a bit too self absorbed with it at this point.)

[tas850g]

I'm battling a very similar problem for months. Bought seals from the same vendor. Brian mentioned a few good things to try to narrow down where the problem may be. If those suggestions don't work then I'm going to check the pistons and seals.

You can't beat experience and knowledge.

[Agemax]

I'm still squeezing the brake every time I walk through the garage. Hard to believe this long national nightmare is over. (I might a bit too self absorbed with it at this point.)

good job it wasnt a problem with the nipple then!