Monkeylad Madness! - thanks

Bernard Littau bernardl at
Tue Aug 19 17:16:55 EDT 2003

> Bernard, your comments got me to thinking that maybe the valve is
> redundant
> anyway, because wouldn't the abs system take care of any wheel lock up
> under
> the circumstances you describe?

Yes and no.

In the extreme, yes, the ABS system will detect the lock up and modulate the
rear wheels.

The rear brakes are both controlled by one ABS channel (on the 5ktq), so if
either wheel locks, both are modulated.  In straight line braking, you might
be ok trading the proportioning valve for ABS as far as function goes, but
triggering the ABS is decidedly more ugly than proportioning the rears.

In a corner, where the inside rear wheel is un-weighted and much more prone
to lock up, the single channel ABS would reduce the brake effectiveness of
the outside wheel unnecessarily.  So no, the ABS would not have equivalent
function to the proportioning valves.  The two proportioning valves reduce
the brake pressure to the inside wheel with much less affect on the other
wheel than ABS.



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