[Shotimes] SHO brake drag--nothing has helped yet (sort of long, but crucial to resolve)

[Zach Leahy]

Huh, funny.  My left front caliper on the green car is stuck right now...

But those came out of a junkyard 3 years ago with no rebuild.  So I
would guess the caliper is bad for me.  I have not yet really fixed
the problem.

Z

On 5/18/05, Jim Koper <jkoper@frankgates.com> wrote:
> This may be somewhat long, but hopefully a thorough description will help
> develop an accurate solution.
> 
> My left front brake is dragging--it smells like it! It feels hotter, too.
> Over the course of several months I replaced the obvious: the flex hose (the
> old one was ballooning); the caliper--twice (free LTW replacement, Warner
> brand); slider pins (first set looked dried out, most recent set was dried
> out and rusty, so I reconditioned with emery paper); bled the brakes again.
> 
> Brake is still dragging. PFCM pads show even wear from side-to-side and
> front-to-rear. A little white residue on pads due to the sticking and
> resulting heat transfer.
> 
> What are the chances of getting two defective calipers in a row (purchased
> 8+ months apart)?
> 
> I've used synthetic caliper grease (blue stuff) and then tried wheel bearing
> grease as slider pin lubricant. Both seem to dry up prematurely--the pins
> rarely come out 'wet with grease.'  I was very surprised at the rust this
> time, but even after reconditioning with emery and regreasing the pins, the
> brake still drags. Any other suggestions for pin lube?
> 
> Could the (original) master cylinder be defective? It passes the "lift the
> pedal with your toe" test with no signs of sinking.
> While the pedal is firm while braking, I notice at stop lights that, with my
> foot on the brake pedal, it will sink slowly, perhaps an inch or two. If I
> lift off the pedal and pump it again, it firms up again. Is THIS a sign of a
> defective power booster or an internal leak? Is there a test that I or the
> (shudder!) dealer can do to rule out replacing the master cylinder? Wouldn't
> the brakes drag on all four corners if the MC were bad? High speed stops and
> normal braking are not a problem, so I doubt if it's a matter of some air in
> the system.
> 
> ANY possibility that the wheel bearing might be going out and THAT is what
> is causing the sticking--and maybe that's what I am smelling? I don't hear
> the 'traditional' parking lot slow-turning noises at all, though there seems
> to be a slight play in the tire (the "12 and 6 o' clock"  test). This
> dragging has been going on for 1+ years, so I figure a bad wheel bearing
> would have gone out LONG ago....
> 
> ANY chance that the spindle / hub might be bent a bit, causing binding for
> the caliper assembly?
> 
> Feel free to chime in. I am open to everyone's experience and advice on
> this. I'm at my wits end and about ready to replace all four calipers, pins,
> flex hoses, and e-brake cables (need those anyway) AND the master cylinder,
> if that what it takes. (I'd hate to spend all that time and money and still
> have the problem..)
> 
> Thanks in advance!
> 
> Jim Koper
> 1992 red on black
> 151,000 miles
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