Re: Proportioning valve was "master cylinder"

[Darrel <darrelK@domain.elided>]

Doug Rasmussen wrote:

>  Darrel K wrote:
> >It's dangerous to run without a stock type proportioning valve! Regardless
> if
> you have a aftermarket valve or not.<
>
> Darrel,
>
>   I don't understand your reasoning.  I suppose a stock type
> proportioning valve might be better than none.  But,  that
> valve is only setup for a *stock* system.  When you start
> modifying the braking system that valve would no longer
> give the corrrect front/rear bias which might be a dangerous
> situation.  My recommendation is to throw the stock valve
> out and replace with an adjustable version.  Then "tune" the
> system so the bias is 60% front-40% rear.
>
>   Tuning the system may be tricky, Wilwood suggests
> the tuning be done on hard packed dirt.
>
>   Given that the most dangerous braking scenario is a
> rear wheel only lockup,  I would want to be very careful in
> replacing rear drums with more effective rear discs.
>
>   Am I wrong?
>
> Doug

Doug,
I'm not referring to the proportioning section of the valve, but the switch
which warns you of problems. Like the 20 year old rear brake line that develops
a leak.
I agree with you that the factory valve may not work correctly with rear disks,
although the bias with my rear disk setup is surprisingly good.
Maybe the best solution is to switch to the Cadillac or some other 4 wheel disk
brake proportioning valve. Add the adjustable version if testing proves that
the rear is locking up too soon.

Darrel Kline
Colorado Springs, CO