Improved valve features a fine thread adjuster for precise pressure adjustments
ADJUSTABLE PROPORTIONING VALVE
PART NUMBER: 260-8419
DS-488B REV DATE: 06-25-12
MAX PRESSURE REDUCTION 57%
INLET / OUTLET PORTS 1/8-27 NPT
MOUNTING HOLE DIAMETER .250 INCH
MOUNTING HOLE SPACING 1.00 INCH
WEIGHT 5.2 OUNCES
INSTALLATION & ADJUSTMENTS - Proportioning valves are normally installed in the rear fluid line to
prevent the rear wheels from locking before the front wheels, or to give a driver the ability to make fine
adjustments in front to rear bias percentage on the track to compensate for tire wear, fuel load burn-off, or
changing track conditions. It is generally not recommended to attempt to reduce front wheel braking capacity.
Use only the two .25" body holes to secure the valve to a mount. Do not attempt to remove the adjuster knob
or valve body end cap to facilitate thru-panel mounting.
Two 1/8-27 NPT to 3/8-24 inverted flare fittings are supplied to adapt double flared hard brake lines to the
valve. Connect the "IN" port to the pressure line coming from the master cylinder. Connect the line going to
the calipers to the "OUT" port.
The adjusting knob is marked with an arrow indicating the direction required to decrease line pressure to the
calipers. The knob rotated all the way out (counter-clockwise) will provide a maximum pressure reduction of
57%. Rotating the know in (clockwise) will incrementally increase line prressure, up to full pressure. If the
range of adjustment in the valve is not sufficient to properly balance the vehicle’s bias, changes to other
components within the system may be necessary.
TESTING THE SYSTEM - Do not attempt to operate the vehicle until the system has been fully tested under
controlled conditions in a safe location. After the system has been bled, checked for leaks, and the proper
pedal resistance and travel have been determined, make a series of low speed stops, then gradually progress
to normal operating speeds.