Any L'Cruiser brake gurus about? HZJ75 load balancing +Rear Drums

Back in the 70's on domestic vehicles, they started using a
proportioning valve for the rear brakes on station wagons and pickups at
first.

This valve senses the amount of pressure going to the front and read
brakes and shunts the pressure so the rear shoes will not lock up the
rear wheels. This is a safety thing so the vehicle doesn't have the
rear end trying to pass the front end.

With a vehicle jacked up, the front wheels lock and the rears appear not
to stop. When it is in motion, this changes because it take more
pressure to stop the fronts so the rear sees a lot more too.

Even on gravel or snow the rear wheels are never supposed to lock except
when coming to that last little bit of a hard stop.

I don't know if this answers your question or not.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


crusty4runner wrote:
>
> Hoping for some input on a problem with rear brakes on a troop carrier
> [2/91manuf].
> Original problem was the escape of the leading shoe on RT/HND Rear set
> from the slave , creating a jammed wheel.
> On inspection of all parts the system was found to totally inundated
> with signs of moisture stress.
> A complete clean [blow-job] together with master cylinder and load
> sequencing valve replacement delivers this new (?) problem, as put
> here
> The brake system bleeds normally as in pedal to master cylinder
> reaction when releasing and pressurizing the system.. When the system
> is closed the brake pedal reacts normally. On starting the engine the
> pedal depresses the standard amount. With the vehicle stationary the
> pedal travel is acceptable. With the vehicle in motion the pedal
> travel extends beyond 50% and only the front discs are activated on
> any attempt to brake (measured or emergency). The rear drums appear to
> have no pressure whatsoever exerted on them.
> I am casting a suspicious eye at the load sequencing valve, primarily
> because I do not understand how it works (hydraulic). I am looking for
> someone to explain the theoretical design of such a
> contraption :-)
> In the event I have missed something very obvious I would appreciate a
> complete jerk back to reality.
>
> thanks.
>
> crusty