• THE MALE THREAD ON THE BLOCKING SOLENOID IS 1/8" M.P.T (MALE PIPE
  THREAD). THIS IS A TAPERED THREAD.


• INSTALL TEFLON TAPE ON MALE PART OF THIS THREAD.


• THE FEMALE THREAD IS 3/16" I.F. (INVERTED FLARE). THIS IS THE THREAD OF
  STANDARD AUTOMOTIVE BRAKE LINE TUBING, AS WELL AS CHAMPION TRAILER'S
  STAINLESS BRAKE LINE TUBING.


• 3/16" BRAKE LINE TUBING OR MALE BRAKE HOSE THREADS WILL SCREW

DIRECTLY INTO THE FEMALE THREAD OF THE BLOCKING SOLENOID VALVE.


• 3/16" I.F. THREADS SEAL AT THE FLARE JOINT AND DO NOT REQUIRE TEFLON TAPE
  AS THREAD SEALANT


• THE SINGLE WIRE COMING FROM THE BLOCKING SOLENOID NORMALLY
  CONNECTS VIA A PLUG TO THE TOW VEHICLE'S "WHITE" BACK-UP LIGHTS. WHEN
  THE TOW VEHICLE IS PUT INTO REVERSE THE BACK-UP (WHITE) LIGHTS COME ON
  AND THE SOLENOID VALVE IS ACTIVATED BLOCKING FLUID PRESSURE FROM
  BEING APPLIED TO THE BRAKES.


• BE SURE THAT THE [WHITE] BACK UP LIGHTS DO NOT COME ON IN ANY OTHER
  GEAR OTHER THAN REVERSE. IF THEY DO, THE BRAKES WILL BE DISABLED IN
  THAT CONDITION.


• BLOCKING SOLENOID VALVES ARE VERY EFFECTIVE AND ARE USED ON MANY
  DISC BRAKE APPLICATIONS, HOWEVER IF YOU ATTEMPT TO BACK UP, IN AN
  UPHILL CONFIGURATION, IT MAY OCCUR THAT YOU WILL HAVE A PARTIAL
  ACTIVATION OF THE SURGE BRAKE COUPLER DUE TO THE COMPRESSIVE
  FORCES BEING APPLIED BETWEEN THE TOW VEHICLE AND THE TRAILER, PRIOR
  TO BACKING UP. THIS MAY DRASTICALLY IMPEDE YOUR ABILITY TO BACK UP THE
  HILL.
  
  IF THIS OCCURS YOU MAY WANT TO CONVERT YOUR REVERSING SOLENOID TO A
  BLEED TYPE SOLENOID VALVE. WITH A BLEED TYPE SOLENOID VALVE, WHENEVER
  THE SOLENOID IS ACTIVATED, ALL FLUID PRESSURE IN THE SYSTEM IS DUMPED
  BACK TO THE RESERVOIR. THIS IS THE PREFERRED SOLENOID VALVE IF BACKING
  UPHILL IS ONE OF YOUR TOWING CONSIDERATIONS.
  
  HOWEVER, THE BLEED TYPE SOLENOID [PART # 1504] REQUIRES THAT A RETURN
  LINE BE INSTALLED BACK TO THE BRAKE COUPLER MASTER CYLINDER
  RESERVOIR.
  
  WHEN USING A BLEED TYPE SOLENOID VALVE, IF THE MASTER CYLINDER IS NOT
  EQUIPPED WITH A RETURN PORT MACHINED INTO IT, IT WILL BE NECESSARY TO
  DRILL AND TAP A 1/8" NPT RETURN PORT HOLE IN THE LOWER HALF OF THE
  MASTER CYLINDER RESERVOIR.
  BE SURE TO KEEP METAL SHAVINGS OUT OF THE MASTER CYLINDER UPON
  COMPLETION OF THE MACHINING OPERATION.

PART # 1504 - REVERSING SOLENOID VALVE OPERATION:

PART # 1504 IS A 3 PORT (BLEED UPON ACTIVATION) SOLENOID VALVE. IT HAS A 1/8" NPT
(NATIONAL PIPE THREAD) FOR THE (IN) PORT WHICH HAS A STAINLESS SCREEN
INTERNAL TO THAT PORT. THIS IS THE PORT THAT IS CONNECTED TO THE HYDRAULIC
OUTPUT PORT FROM THE MASTER CYLINDER OF THE BRAKE COUPLER.

DIRECTLY OPPOSITE FROM THE (IN) PORT ON THE SOLENOID VALVE, IS THE PORT THAT
IS CONNECTED TO THE BRAKE LINE TUBING GOING TO THE TRAILER BRAKES.

THIS PORT HAS 3/16" (I.F. - INVERTED FLARE) THREADS, WHICH IS THE THREAD FOR
THE STANDARD BRAKE LINE TUBING, AND BRAKE HOSES. DO NOT INSTALL TEFLON
TAPE ON THREADS FOR 3/16" I.F. FITTINGS!THEY ARE SELF SEALING.

THE THIRD PORT HAS 1/8" NPT THREADS AND HAS A 90° BRASS BARB FITTING
INSTALLED. THIS FITTING IS WHERE THE RETURN LINE RUBBER HOSE IS CONNECTED
FOR ROUTING BACK TO THE MASTER CYLINDER RESERVOIR.

IF YOUR MASTER CYLINDER DOES NOT HAVE A RETURN PORT MACHINED INTO THE
MASTER CYLINDER RESERVOIR, YOU WILL NED TO DRILL AND TAP A 1/8" MPT HOLE
INTO THE LOWER HALF THE REAR OF THE RESERVOIR. BE CAREFUL NOT TO GET
METAL SHAVING IN THE MASTER CYLINDER DURING THE MACHINING PROCESS.

THE (IN) PORT OF THE SOLENOID IS COMMON TO THE PORT WITH THE 3/16" I.F.
THREADS, GOING TO THE TRAILER BRAKES. WHEN THE SOLENOID IS NOT
ELECTRICALLY ACTIVATED BRAKE FLUID FLOWS IN AND OUT THRU THESE PORTS,
DIRECTLY TO THE TRAILER BRAKES. WHEN THE SOLENOID IS NOT ELECRICALLY
ACTIVATED, THE RETURN PORT (GOING BACK TO THE MASTER CYLINDER RESERVOIR)
IS CLOSED (NOT OPEN TO THE BREAKE SYSTEM.
WHEN THE SOLENOID VALVE IS ELECTRICALLY ACTIVATED, THE RETURN PORT OPENS,
(BECOMES COMMON TO THE BRAKE SYSTEM PRESSURE). THIS ALLOWS ANY AND ALL
BRAKE SYSTEM PRESSURE TO BE RELEASED BACK TO THE MASTER CYLINDER
RESERVOIR VIA THE RETURN LINE HOSE.

ELECTRICAL ACTIVATION OF THE SOLENOID IS TYPICALLY ACCOMPLISHED BY
CONNECTING THE VALVE ELECTRICAL WIRE VIA A PLUG INTO THE TOW VEHICLE
BACK-UP LIGHTS. WHEN THE TOW VEHICLE IS PUT INTO REVERSE, THE SOLENOID IS
ACTIVATED AND THE TRAILER BRAKES ARE DISABLED.

BE SURE THAT THE BACK-UP LIGHTS DO NOT COME ON IN ANY GEAR OTHER THAN
REVERSE. IF THE BACK-UP LIGHTS COME ON IN ANY OTHER DRIVING CONDITION THE
BRAKES WILL BE DISABLED DURING THAT CONDITION.

THE BLEED SOLENOID IS THE PREFERRED BRAKE LOCK OUT SOLENOID VALVE IF YOU
ARE FINDING IT NECESSARY TO DO BACKING UP OPERATIONS IN AN UPHILL MODE.

IF YOU TOW ONLY IN FLAT LAND DRIVING AND BACKING-UP CONDITIONS THE
BLOCKING SOLENOID [PART # 1507] MAY FULFILL YOUR BRAKE LOCKOUT NEEDS. WITH
THE BLOCKING SOLENOID (PART #1507) IT IS NOT NECESSARY TO HAVE A RETURN LINE
BACK TO THE MASTER CYLINDER RESERVOIR, HOWEVER IF BACKING UPHILL THE
BLOCKING SOLENOID MAY CAUSE DIFFICULTY.