Forward from rec.motorcycles (was: Brakes are breaking me!)

[Doug Saylor <absdoug@xxxxxxxxx>]

On 22 Feb 2005 18:33:40 -0800, "bsr3997@xxxxxxxxxxx" <bsr3997@xxxxxxxxxxx> wrote:
>The fluid should shoot up in the reservoir when you let the lever back
>out, not when you pull it in.  When you pull the lever in the piston
>closes a port to trap the fluid so it can be forced down the line.
>More fluid is drawn from the reservoir to fill the space behind the
>piston.  When you release the lever it is that fluid that squirts up.
>If you have bled fluid out it will not squirt up so much because some
>of it goes to fill in front of the piston.  
 
Seems to work backwards on my BMW. The squirt takes place when  you activate the brake. The way you describe sounds like it makes more sense. Wonder what the deal is with that.
 
>If you don't let the lever
>all the way out it will not uncover the port to let more fluid in.
>Some setups have adjustments for lever position that can mess this up.
>If the piston doesn't come back far enough to uncover the port, it
>traps the fluid in the line. 
 
This is what was happening with me. The adjustable lever was not the problem, but there is another adjustment I had wrong. Trying to collapse the pistons on the calipers was a NIGHTMARE and now I know why!
 
>As the brakes heat up from use the fluid
>can expand, causing the brake to stick on.  This could be the cause of
>your sticky calipers.  We have actually had front brakes lock on at the
>race track causing crashes.
 
Bingo. That was indeed the problem as far as I can see.
 
>Put a clear plastic line on the bleeder.... <snip> 
 
I found a leak in the line on top of my original problem! Had a spare part. I bleed and bleed and got lots of bubbles. Eventually the bubbles stopped having done EVERYTHING in detail that was suggested. Still mushy, still the lever comes back too far.
 
>If fluid is in fact squirting up when you pull the lever in, it could
>mean you have a bad seal in the master cylinder.
 
Please elaborate, cause I remember this squirting to be the same when the master cylinder was replaced ... it will be coming up on a year soon.

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