Poring over the pressure flow diagrams for the newer 727, I see why there is a second spring on the shuttle valve. That spring is related to the lockup function and the 3-2 limit valve. Since neither of those apply to this valve body, I'll be skipping that spring.
The regulator valve has still got me stumped. To clarify, the second spring behind the regulator valve does not have any direct impact on the valve's travel. Line pressure pushes the line pressure plug (duh!) toward the regulator valve, compressing the spring. Throttle pressure pushes the throttle pressure plug (double duh!) away from the regulator valve, extending the spring.
The regulator valve controls line pressure depending on throttle pressure. So this second spring has something to do with balancing the two.
Thanks,
David
Back to the Home of the Forward Look Network