[s-cars] Rear brake saga - The Questions have Ended!

[Theodore Chen]

--- Eric Phillips <gcmschemist at gmail.com> wrote:

> The loctite idea is a good one.
> 
> My vocation is as a chemist using gas chromatography - and the gases
> used are usually under high pressure.  Teflon tape is a crutch in
> cases where a fitting is "almost good enough, but not bad enough to
> justify the expense of replacing it."  Being careful with what happens
> to the leftovers is a very important part of using it.  I would have
> preferred using loctite, though.  I may yet, except that I wonder if
> it works when brake fluid is covering all the threads of the
> caliper...

yeah, it works.  remember, loctite PST thread sealant, not loctite 
threadlocker.

> On the pedal-bleeding front - how do you get the fluid to flow only in
> one direction?  Is there a check valve in-line somewhere?  Let up on
> the pedal, the piston in the MC comes back, pulling fluid back from
> the caliper and the resevoir?  The stuff from the resevoir is OK, but
> pulling it back from the caliper is sort of opposite of what you want,
> LOL.

for one thing, brake fluid would have to flow against gravity and
through a long tube to come back into the master cylinder.  there's
a reservoir of brake fluid sitting right above the master cylinder 
with gravity trying to push brake fluid in.  you WANT to refill the
MC with brake fluid from the reservoir, since that's where you're 
adding fresh brake fluid, and that's in fact what happens when you
release the brake pedal.

> I would have greatly preferred to use your method - it would have been
> faster and much less fussy.

yes, it is much easier.  i tried using a vacuum bleeder once.  it took
far too long, and didn't produce better results.

-teddy

> 
> Eric
> 
> On 2/22/06, Theodore Chen <tedebearp at yahoo.com> wrote:
> > eric,
> >
> > next time, use loctite PST to seal the bleeder screws.  the problem
> > with teflon tape is that you wind up with a lot of shredded tape when
> > you remove or loosen the screw, and you don't want shrapnel floating
> > around in the brake fluid.
> >
> > i don't use anything special to flush my brakes.  i just put a piece of
> > tubing on the bleeder screw and aim it into a jar.  i bleed both calipers
> > on one side of the car at a time (first the passenger side, then the
> > driver side) by pumping the brake pedal.  pump 8 times, refill MC, repeat
> > until fluid coming out is clear.  as long as the bleeder screws aren't
> > leaking, no air will get sucked into the calipers when you release the
> > pedal, because there will be fluid in the tubing.  i've been doing this
> > for years, including on my race cars, and never had any problems getting
> > a solid pedal.
> 


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