Locking Tag Axle Tire

[Jeff Miller]

The "port effect" in diesel injection (ex: 3208) is due to the metal
lines stretching and contracting delaying the injection pulse (like
water in a hose in an old Bugs Bunny cartoon), where in air brake
lines the delay is due to the compressed air pulse traveling along
the lines and the inertia of the air. You are correct Day that
eventually the pressure will be the same at all points in the line,
but line lengths and diameters will affect the time that this
pressure takes to reach the brake chamber at the end of the line.
Twice the line length will take roughly twice as long, just like
sound waves. This was one of the factors I had to take into
consideration when designing an air-brake system for the Futurliner
thanks largely to a generous donation from Bendix Brake.

Since the air leaves the relay valve and is split at the valve into
the two lines, the air pressure will also take the path of least
resistance (lower pressure) which can also cause one brake to get a
larger force momentarily due to a restriction, once the wheel stops
then inertia and the difference between dynamic friction and static
friction can retain the locked condition.

Have to consider all possibilities when asessing a problem, I'm still
thinking it's a mechanical problem though and hope he posts the
solution/findings.

- Jeff Miller


--- In WanderlodgeForum@yahoogroups.com, DAY8293A@C... wrote:
> THE LENGTH ON THE INJECTOR LINES ARE PRECISE DUE TO THE
TIMING FOR THE
> FUEL TO BE INJECTED INTO THE CYLINDER AT A PRECISE TIME. (WHICH OF
COURSE YOU
> KNEW)
> THE LENGTH OF THE AIR LINES ARE NOT PRECISE FOR "TIMING"
BECAUSE AIR
> PRESSURE SHOULD BE EQUAL THROUGHOUT THE LENGTH OF THE LINES. ALL
BRAKES ARE
> SUPPOSED TO APPLY AT THE SAME TIME. THE LEFT SIDE DOES NOT APPLY
BEFORE THE
> RIGHT SIDE. THE AIR PRESSURE WILL BE THE SAME AT ALL POINTS
THROUGHOUT THE LINE.
> IF A DIFFERENCE DOES OCCUR, IT WILL BE DUE TO OBSTRUCTIONS,
RESTRICTIONS, OR
> SOME OTHER PROBLEM. DAY JAX FLA 83 PT-40.
>
>
> [Non-text portions of this message have been removed]