Quote:
Originally Posted by Bowtie2Bimmer
Front caliper has been rebuilt per say, just thoroughly cleaned. I'm considering getting all new seals for the caliper and a MC rebuild kit.
What about the line? Could it be swelling for some reason, causing fluid to be pushed out into the caliper?
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There is no mystery about this:
When pressing on the MC's cylinder, there is a volume of fluid trapped inside the system (among the small piston in the MC and the bigger pistons in the caliper).
Case 1:
Heat is transferred into the fluid.
If it is pure fluid, that heat makes that volume grows, but not enough to be noticed.
If the fluid contains humidity, that heat makes that tiny amount of water become steam and the volume of that water grows about 1600 times.
That clamps any pad for as long as the temperature of the fluid+steam remains high enough.
Case 2:
The relief orifice (compensating port) in the MC is dirty/clogged and/or the return spring is broken/weaken.
In both cases, the problem does not allow part of the fluid trapped among the small piston in the MC and the bigger pistons in the caliper to normally return back to the container (compensating for any variation of volume due to temperature), reducing the volume and pressure inside the caliper enough to release pad's pressure over the disc.
Any deformation of the hose under pressure would have the opposite effect: it becomes harder to clamp/lock the pads.
Click on Theory Video and on Animation:
http://search.lv2014.integr8cms.net/...aster-cylinder
