[TR] Spit: 2 dumb discoveries, 1 to go?

[Jim Muller]

And here is part two:

> So I got out a new master cylinder seal kit and put in the seals.
> ...Installed the mc, filled it (did not bench bleed it) and bled
> the brakes with my wife pushing the pedal.  It took forever.

That just ain't right.  It shouldn't take forever.  It shouldn't take
long at all.  Are you really getting fluif out of each wheel's SC?  
If you are sure the system has fluif instead of air, then your MC 
isn't sealing, isn't generating any pressure.  Jack up one wheel (at 
least) and have someone or a length of wood depress the brake pedal.  

Does the jacked-up wheel turn at all?  Are you sure you don't have a 
leak?  Maybe a hose is leaking and squirting fluif where you can't 
see it?


> Despite blowing out a piston earlier, the brake light comes on
> only at startup and goes off after that.

I would have thought the brake light *should* have come on.

> That means both front and back systems should be okay, right?

No.  If one system (i.e front or rear) lost pressure and the other 
didn't, the PWDA should have come on.  A stuck PDWA piston or a 
disconnected wire will make the warning non-functional.  The light 
comes on at start-up only because it also comes on with the oil 
pressure warning light.  That simply proves that the bulb is okay, 
not that the warning system is functioning.

I'm starting to get an idea...  When you bleed the brakes, do you see
fluif coming out of the nipple on each wheel?  You may have one or 
more flexible hoses with a tear inside that is preventing fluif from 
moving.  It could have been keeping the pressure on for a wheel or 
two, which would have explained the pulling.  (I wonder how easily 
the car rolled when the brakes weren't applied.  I bet it didn't roll
easily.)  Now that you are trying to re-bleed the system out of 
necessity, the same problem(s) could keep fluif from moving into the 
system, i.e. keep air from moving out of it.  You step on the pedal 
but nothing in the system moves.  So the air remains.  It is hard to 
imagine that both front and rear systems developed a problem like 
this together, but coincidences do occur except in TV cop shows.  Or 
instead of the flexible hoses you have have gummed up metal lines 
such that both front and rear are jammed.

Re-bleed the system and check that fluif actually comes out.  If you 
see fluif, then the problem is that the MC is still leaking 
internally, perhaps both front and rear.  If you don't see fluif, 
disconnect the flexible hose from the metal line at each wheel (one 
at a time, of course).  Have your wife step on the brake pedal 
several times (not so much that it will empty the MC) while you watch
the free end.  If the problem was inside a flexible hose you should 
now see fluif come out.  Perhaps this will blow out any obstruction.


-- 
Jim Muller
jimmuller at rcn.com
'80 Spitfire, '70 GT6+