On Sun, 26 Feb 2006 14:55:26 +0000 (UTC),
wrote:

snip

Not to argue since all I know is heresay at this point, but my mechanic had
problems bleeding a guy's cherokee *even though* they were bleeding bottom-up.
Top-down, bottom-up, it didn't seem to matter.... they couldn't get all the air out.
Ended up having to replace some weird seal/gasket/valve thingy (don't know the
specifics). Apparently it's a common thing to have to replace... maybe why all the
FUD about bleeding Cherokee brakes. Perhaps it's only a PITA if this other thing is
broken. Sounds like Jay doesn't have any trouble.

really depends where the air is trapped in the system. the primary
problem with the Cherokee's is the fluid inlet to the toe cylinders is
on the bottom of the near-vertically mounted cylinder (and goes "up"
to the handbrake and reservoir). the outlet is on the top, and goes
"down" to the calipers.

pressure bleeding from the reservoir or from the caliper is
problematic due to this routing. a little air here or there can
usually be worked out, but if there is a lot of air trapped, the
quickest solution is to remove the toe cylinders (mechanically, not
hydraulically) and invert them. a pressure pot from the bottom will
then clear the lines fairly rapidly.

the nastiest one I ever worked was on a Cheyenne that wouldn't leak
fluid out static or under applied brake pressure, but would leak air
in when the cabin was pressurized. if I hadn't had seen it, I never
would have believed it.

TC