Swampʼs Diesel Performance Competition Parts For Your Diesel 304-A Sand Hill Rd. La Vergne, TN 37086 Tel 615-793-5573 or (866) 595-8724/ Fax 615-793-5572 Email: dave@swampsdiesel.com Regulated Fuel Return System Abbreviations for fittings: MB = Male Boss; threaded fitting with an O-ring seal. MB is also called SAE Strait Thread or -AN. MJ = Male JIC; threaded fitting with an unthreaded tapered point on the end. FJX = Female JIC Swivel; threaded female that mates to a male JIC. JIC is also called 37* Flare. MP or FP = Male Pipe or Female Pipe respectively. Also called NPT for National Pipe Taper. PL = Push-Lock; A type of barbed fitting for hoses. Once you push the hose onto the barb, you CANNOT pull it back off you must cut the hose off, so be careful doing test fits! MB and JIC do NOT use any type of sealant! Use Teflon tape or red locktite on pipe threads. Fitting Sizes: 1/8 = 2, 3/16 = 3, ¼ = 4, 5/16 = 5, 3/8 = 6. (Note that 2MP is a different diameter than 2MB. A 5MB or 5MJ thread is the same diameter and pitch as 1/2-20 fine threads.) Caution: The braided hoses are electrically conductive do not allow them to contact positive voltage sources such as the glow plug relay or the alternator.
. From L to R: 6MJ-6FJX-45, 6MB-6MJ-45, 5MB-6MJ, 4MP-6MJ, and 6FJX-6MJ-6MJ
Parts in Kit: Hoses: (2) 6FJX Stainless Braided Hydraulic Hoses, 16 and 24 long (1) 6 PL Rubber Hose ~12 long Fittings: (1) 2MP x 6MJ (1) 2MP x 4MJ (1) 2MP x 2FP 45* (2) 6MJ x 6FJX 45* (2) 6MJ x 6FJX 90* (2) 6MB x 6MJ 90* (2) 6MB x 6MJ 45* (1) 6BR x 6FJX (1) 4MJ x 6MJ (1) 6 Compression Cap w/internal gasket (1) 1/4 Steel Tube 6 long w/ 4FJX x 4FJX ends Other: (1) Aeromotive A1000-6 Regulator (1) 0-100 psi gauge (4) Hose clamps Installation: Passengerʼs Side Head: Remove the 2MP plug with the square head from the front of the passengerʼs side cylinder head with vise-grips or a 9/32 square socket (try finding one of those!). A 2MP x 2FP 45* fittings goes into where this plug was, and then a 2MP x 6MJ fitting goes into the 45*. Orient them pointing more or less
straight up; you may also need to use one of the 45* JIC swivel fittings to get around things. Use red locktite on the pipe threads. To access the fitting on the front of the passengerʼs head, unplug the sensors on the wiring harness that goes down past the fitting (EBP, EOT, H2O and CPS) and pull the harness up a few inches so it is out of the way. If there is a stud on the rear of the passengerʼs side of the high pressure oil reservoir, remove the stud so its easier to get your hand/fingers down into where the fitting goes to thread it in. Threading in this fitting is the hardest part of the job. You can also remove the engine serpentine bolt and unbolt the accessory bracket from the front of the engine to get even more room. Driverʼs Side Head: Remove the air intake tubes from the air filter to the turbo to get access to the rear of the head. Remove the square head plug from the rear of the head and install the 2MP x 4MJ straight fitting, and then the 1/4 steel tube. Orient the tube so it is pointing forward. Attach the XX braided steel line to the 1/4 tube using the 4MJ x 6 MJ adapters. Install the 16 hose on the front head and the 24 hose on the rear and point them towards the passenger side intercooler pipe where it connects to the Y pipe. Thread a 1/4-28 nut onto each of the ends of the intercooler hose clamps, slide the regulator over the threads, and then fasten it with two more nuts. Connect the hoses to the regulator with a 6MB x 6MJ 90* on the passengerʼs side and a 6MB x 6MJ 45* on the driverʼs
side. Additional fittings are included to give more flexibility in routing the hoses. To adjust the fuel pressure, one turn of the stud changes the fuel pressure ~15 psi. (Tightening the stud increases pressure.) When installation is finished, adjust the pressure to ~70 psi. There is no specific pressure that is best, but generally 60-70 is fine. Install a 6MB x 6MJ 90* into the bottom of the regulator and point it towards the front of the engine. Unscrew the tube nut for the return line on the driverʼs side of the fuel bowl near the top; carefully bend the tube out from under the other tube, point it towards the regulator, cut the flare off of the end of the tube with a miniature tubing cutter, and remove and discard the nut. Remove the aluminum fitting on the side of the bowl where the tube connected, and install the black cover in place reusing the original screws. Cut the 6PL hose so it reaches to the cut tube end and push the rubber hose over the tube and tighten the hose clamps. Tighten the 6FJX x 6PL fitting on the other end of the hose onto the outlet of the regulator. Tighten the lock nuts on the MB fittings after you have the pointed in the right direction. Installation of the regulator is now finished. Re-connect the wiring harness, air intake and replace the stud in the reservoir. Double check all fittings for tightness, turn the key on to start the fuel pump (do not start the engine) and check for leaks. The fuel pump shuts off automatically after 10-15 seconds, so cycle the key several times to allow fuel to pump through the heads and purge the air out of the system. (The pressure on the gauge will stabilize when the air is out.) After you have checked for leaks you can start the engine.