This didn't get to the "List" on original sending...
"David R. Conrad" wrote:
> Tom, "the List", and "Sages"
>
> "David R. Conrad" wrote:
>
> > That phenomena of the master cylinder not permitting the return of the
> > hydraulic fluid would provide for *exactly* what I've been observing! This
>is
> > particularly true after the discovery I made today...
>
> Others proposed several different mechanisms, by which pressure could be
>built up
> and maintained for a while in the rear hydraulics. To me, the master cylinder
> seemed the most likely. I have a new MC on order being sent Priority Mail...
>
> > ...98% confident that you have identified the cause of the problem that has
> > eluded me for about a full month.
>
> There still remained that 2%...
>
> I was going to remove the existing cylinder in preparation for installing the
>new
> one when it arrived, but thought I'd do a few final tests before doing so.
>
> I had already readjusted the brakes to the "normal" condition; that is, two
> "notches" back from shoe/drum contact - car still on jack stands, and the
>drums
> rotated freely
>
> I "reasoned" that, that if this pressure buildup occurred while driving, it
> should also do so, pumping the brakes while just sitting. So, I pumped the
> brakes "hard" about 20 times. Then, I checked the drums, and found that they
> still rotated freely over the shoes!! (I also had not experienced that
>"hard",
> no-travel pedal.)
>
> So, I put the wheels back on, removed it from the jack stands, and found I
>could
> push it easily in the garage. I then tried the same test of pumping the
>brakes
> hard 20 times. I could still push it easily in the garage.
>
> Then, I put the dog in the car (she loves this!) and went for another test
> drive. With the correctly adjusted brakes I started out with about an inch
>and a
> half of pedal travel. After about a mile and a half of driving, this amount
>of
> pedal travel had reduced to essentially zero and I could feel brake drag
>starting
> to occur. I returned to the garage. I didn't bother jacking the car back
>up, I
> just tried pushing it. Couldn't.
>
> Now, I'm really confused!!
>
> help...
>
> Dave
>
> (Before clicking "send", I couldn't believe what I had just written, myself.
>I
> went down and redid this exact test sequence. The only difference, this time
>I
> pumped the brakes "hard" 40 times - still rolled easily. Then, I drove
>exactly 2
> miles, loss of pedal and brakes started dragging at 1.5. Couldn't push it
>after
> return to garage,)
>
> David R. Conrad" wrote:
>
> > Eureka!! Tom (perhaps*)
> >
> > That phenomena of the master cylinder not permitting the return of the
> > hydraulic fluid would provide for *exactly* what I've been observing! This
>is
> > particularly true after the discovery I made today.
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