Author Topic: Front Brake Drag  (Read 4272 times)

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Boogerbandit04

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Front Brake Drag
« on: June 11, 2008, 02:30:25 pm »
So I have heard this from a few people now that the front brake is notoriously bad at dragging after repeated use, this comming from there always being some pressure asserted on the brakes even after the lever is released. Does anyone know how to correct this issue? I was thinking about upgrading to dual disc in the front off a 750F, but Im still a noob so I would like suggestions first. Thanks in advance.

Boogerbandit04

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Re: Front Brake Drag
« Reply #1 on: June 13, 2008, 05:54:26 pm »
Im still having this issue. Now the brakes make a slight sqwealing when the brake isnt applied. WHAT THE HELL, I am loosing my mind. Can anyone help?

Offline bradweingartner

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Re: Front Brake Drag
« Reply #2 on: June 13, 2008, 06:04:18 pm »
What a lot of people don't realize on these older bikes is that the brakes need to be adjusted regularly. The caliper isn't completely free floating. You need to adjust the caliper so the fixed pad is in good proximity to the rotor. As the pad wears you need to adjust it further.

It takes a little tweaking to find the point where it doesn't drag real bad but also doesn't chatter or squeal.

Another issue is if your caliper seal isn't in good shape, the small deformation that causes the seal to pull the piston away from the rotor may not be as significant as you need. This can put a little extra drag on your brakes. A caliper rebuild can make a difference in this department.

Boogerbandit04

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Re: Front Brake Drag
« Reply #3 on: June 13, 2008, 06:39:59 pm »
Can you stear me to the parts I would need to rebuild the caliper? I didnt realize I had yo adjust the brake though.

Offline 333

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Re: Front Brake Drag
« Reply #4 on: June 13, 2008, 06:41:02 pm »
Another possibility is that the caliper and/or the master cylinder needs to be rebuilt.  If the bike has to stay out in the weather, the caliper needs to be rebuilt about every 2 years.  It only involves replacing a squared o-ring.  Dirt and stuff build up in there just outside the seal and jam the piston from moving freely.

The master cylinder is a little harder.  It pushed brake fluid down the line(obviously).  When the brake handle is released, a spring pulls the pump piston back, while a check valve opens allowing the fluid to come back into the fluid reservoir.  The check valve often fails, not allowing the brake to release.  So whether the caliper piston jams, or the master cylinder check valve fails, the same symptom appears.  Rebuilding the master cylinder involves long, needle-nose snap-ring pliers.  You should also flush out all the old brake fluid(don't be tempted to use DOT 5).  If you add replacing the pads, you've completely rebuilt the front brake.
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Boogerbandit04

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Re: Front Brake Drag
« Reply #5 on: June 13, 2008, 07:00:06 pm »
I had the MS rebuilt about 5 weeks ago, so its DEFFINITLY not that. I think its a mixture of the brake needing adjustment and the caliper needing to be rebuilt. This seal is all that needs to be replaced?

Offline Gordon

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Re: Front Brake Drag
« Reply #6 on: June 14, 2008, 09:58:29 am »
This seal is all that needs to be replaced?

As long as the piston isnt' rusted/corroded too much. 

Before you disconnect the brake line, remove the caliper and use the brake lever to pump the piston out.  That's the easiest and cleanest way of removing it. 

Boogerbandit04

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Re: Front Brake Drag
« Reply #7 on: June 14, 2008, 11:25:48 am »
Good Idea, Im trying to do all the easy mechanical stuff myself (brakes are one of the EASIEST things I have ever worked on, and important). I sprayed the calipers down with brake cleaner yesterday and it seemed to help a bit. A TON of brake dust-n-#$%* came out. No more sqwealing, and I'm going to wait until the pads need replaced before I rebuild the caliper. I bought the seals, new brake lines and some oil seals (to drip drippin everytime I park the bike). Thanks for your help guys, until the next problem

Offline Frankenkit

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Re: Front Brake Drag
« Reply #8 on: June 14, 2008, 09:31:36 pm »
Another thing I'd note here is when I rebuilt my MC, I found a lot of really chunky, almost crystallized old brake fluid in around everything.  I cleaned these chunks out, but the natural progression of thought is "Oh, if that's up here, what's it look like in my caliper?" 

My caliper was full of the same nasty chunks.  Might help to clean all that stuff out, too, if you can.
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