2013-2018 6.7 Cummins S400 Over Stock Twin Turbo Install Instructions

Covers installation of PN: WCF100631

Note: This Kit is for off road competition use only!

Important Note! Installation of this turbo kit requires the Air Conditioning system to be drained. If

you do not have an AC machine you will need to schedule with a local automotive shop to have your AC

system drained BEFORE STARTING TEAR DOWN OF THE TRUCK. Once Installation of the kit is complete,

then have your system recharged.

1. First, locate the Packing list included with the kit and double check you have all items on the list.

2. Disconnect the negative battery cables from both batteries.

3. Drain the coolant from the truck.

4. Remove the factory intake from the truck. Remove the two sensors on the intake tube and set

aside in a safe place, they will be reused later.

5. Remove the passenger side battery and battery tray. The Glow Plug relay can be unbolted from

the tray and stay on the truck.

6. Remove the cast elbow on the outlet of the factory turbo and the front section of your exhaust

system. Set aside the V-band clamp that held the cast elbow TO the turbo, this will be reused

later.

7. Remove all 3 air conditioning line assemblies from firewall to compressor, compressor to

condenser, and condenser to firewall.

8. Remove the coolant stand pipe from the back of the water pump shown below. Also remove the

hoses and lines that are connected to it that feed the cylinder head, turbo center section, and

the coolant tank.

9. Next you will want to remove the freeze plug from the passenger front side of the block below the oil filter housing. Using a long narrow punch and a hammer, tap on one edge of the freeze plug until it rotates enough to grab it with pliers and remove it. This will create the port for the second turbo’s drain line fitting. Pictures below show the now open port on the side of the engine block, and the removed freeze plug.

10. Apply grease or assembly lube to the new turbo drain fitting. (-10 JIC black fitting with two O-

rings) With a rubber mallet tap the new fitting into the hole on the engine block.

11. Install the stainless braided turbo oil drain line to the above fitting. The 45-degree end of the line should be pointing up, the straight end connected to the fitting in the engine block.

12. Next remove the factory coolant overflow tank. The rubber spacer from the factory coolant tank will need to be removed and reinstall onto the new fabricated coolant tank mounting leg. Picture below shows the spacer installed on the new tank mount.

13. Apply pipe sealant/paste to the threads of the supplied low coolant level sensor and install the sensor into the new coolant tank. Ensure that the arrows on the side of the hex of the sensor are facing up, towards the fill port of the tank so that the sensor will read properly.

14. Install the supplied aluminum 1/8” NPT X 5/16” barb fitting onto the fill neck of the tank. This is the overflow port, application of pipe paste is still necessary as to not causing marring of the threads.

15. You can now install the new coolant tank in the OEM location. You will reuse one of the factory coolant tank mounting nuts and the provided M6X16MM bolt to attach the tank to the fender and firewall. The OEM coolant hose on the top of the tank can be reconnected. The supplied 5/16” heater hose can be installed on the neck of the tank for the overflow port.

16. Locate all contents of the Heater Line Reroute Kit as shown on your packing list.

17. Apply pipe paste to the ½” Brass NPT plug and install into the center port of the cylinder head where the EGR use to feed.

18. Locate the machined aluminum ¾” barbed tee coupling. With aid of a vice (using soft jaws or a shop towel!) you will install the 3/8” NPT X push lock and ½” NPT X 5/8” barb fittings oriented as shown below;

19. Locate the supplied ¾” heater hose and cut the 24” section into one 6” and one 18” piece.

20. Install the ¾” hose as shown;

21. Locate the 24” long 5/8” heater hose supplied and install onto the 90-degree barb of the above assembly. This hose DOES NOT need cut.

22. Install the supplied M16 X #8 JIC fitting with sealing washer into the top of the factory turbo center section coolant port.

23. Install the 90-degree push lock fitting onto one end of the supplied ½” black push lock hose using grease or assembly lube, do not try to install dry. The other end of the hose will be connected to the straight push lock fitting that was installed into the aluminum tee assembly above.

24. Locate the billet aluminum coolant fitting with ¾” barb elbow shown below, which will be installed into the back of the water pump where the OEM coolant stand pipe was removed in step 8.

25. The end of the 18” section of ¾” hose from the assembly made in step #20 will install onto this coolant fitting as shown below. The 6” end of the ¾” hose connects to the new coolant tank, and the 90-degree JIC fitting connects to the turbo, as shown below.

26. The other end of the 5/8” heater hose connects to the bottom port on the firewall and routes as shown in the two-photo’s bellow;

27. Install the supplied Velcro foil heat wrap to the 8” long hose feeding the turbo and the 5/8” x 24” hose feeding the firewall. (both hoses shown in step 26)

28. On the factory oil filter housing remove the 1/8” plug and install the supplied 90-degree fitting with Teflon paste, pointing towards the firewall as shown below.

29. Locate the roll of heat wrap, the 3” and 4” hose clamps, 3” turbo hot pipe, and 4” turbo down pipe. We ADVISE TO WEAR GLOVES! Remove plastic wrapping from heat wrap roll and hold under running water in sink. The heat wrap is much easier to apply, and your able to apply it tighter, if the roll is soaked in water. STARTING WITH THE 3” TURBO HOT PIPE, wrap the hot pipe from end to end using the supplied 3” hose clamps on either end of the pipe to secure the heat wrap. Once completed with the hot pipe, starting at the TOP (flanged end) of the 4” down pipe, wrap it with the remaining length of the wrap using the supplied 4” hose clamps on either end of the pipe to secure the wrap.

30. To install the new hot pipe, you will need to remove the factory exhaust manifold bolts on cylinder #2 & #3. To install the new hot pipe, place the factory turbo outlet v-band clamp around the factory exhaust housing for ease of installation, then lay the hot pipe in place. Slide into the exhaust housing of the factory turbocharger then using the two supplied M10 X 60MM flanged bolt through the pedestal and exhaust manifold into the cylinder head. Ensure that the pipes flange is seated on the exhaust housing of the factory turbocharger, then start the clamp but do not fully tighten yet, only snug. First tighten the two bolts into the cylinder head to 33 ft/lbs. Then tighten the clamp onto the factory turbocharger.

31. Now reinstall the factory battery tray. Once the large turbo is installed you will not be able to do

this, you must install the tray before the large turbo.

32. The transmission dipstick bracket (if your truck is equipped with 68RFE transmission) will need to be twisted just slightly to align with the threaded bung on the hot pipe. Clamp the dipstick bracket with the supplied M6 X 16MM flange head bolt.

33. Remove the exhaust housing from your new S400 turbocharger by removing the v-band clamp. Locate the T6 housing flange gasket (usually in the turbo box) and the four M10 X 30MM flange

head bolts and install the T6 exhaust housing onto the hot pipe. 35 ft/lbs of torque on the flange bolts.

34. BEFORE installing the 4” down pipe is the best time to install the supplied AC Line Kit and fittings. First remove all the OEM studs at each AC port (firewall, condenser, & compressor). The new fittings will be held on with supplied socket head allen bolts in the AC Line Kit. Install all the supplied seal washers on the machined aluminum fittings and install them as shown in the following steps.

35. The following picture shows location and orientation of fittings and hoses at the compressor;

36. Next picture is the single piece (dual port) fitting at the firewall with the long #6 hose and the

large diameter, medium sized length #10 hose connected, both with 90-degree fittings at the connection to firewall. Both hoses running from firewall should have the supplied foil heat wrap installed around the hose where they are near the turbo down pipe and turbo.

37. Connections at the AC Condenser;

38. Now locate the 4” turbo down pipe. This step is much easier with a second person helping. Slide

the down pipe into place from the underside of the truck, while the person above installs the 5” v-band clamp to the turbo exhaust housing. Tighten the clamp once your certain the down pipe is positioned properly that it is not rubbing against any other components and has adequate clearance to the frame, hot pipe, firewall, and transmission.

39. With a tape measure underneath the truck you will measure the distance from the end of the

new down pipe, to your exhaust system so that you can cut the proper amount off the front of your exhaust system front pipe that you removed in step 6. The front pipe once cut to length can be reinstalled and connected to the new turbo down pipe with the supplied 4” seal tight band clamp. It is good measure to install a self-tapping type screw on either side of the seal tight band clamp.

40. Back to the top side of the engine bay, clean the inlet flange of the factory turbo and install the

3 1/2” x 4” silicone boot with clamps. Tighten the 4” clamp at the factory turbo at this time Only.

41. Locate the 3” Cold charge pipe that will connect the s400 turbo to the factory turbo. If you’re not running a boost gauge to watch the atmosphere turbo boost, then install the supplied 1/8” NPT pipe plug.

42. Install the O-ring into the groove on the face of the flange on the cross over pipe, grease can be used to hold it in place.

43. Install the crossover pipe into the 3” x 4” reducing boot but do not tighten yet.

44. Locate the Billet turbo drain flange, #10 fitting, and hardware. Install the drain flange onto the turbo center section, note the flange has a built-in seal, the paper gasket is not needed.

45. Now install the turbo center section into the exhaust housing, the center section can rotate in

the exhaust housing for proper alignment of the oil drain and feed ports which should point straight up and straight down. Once orientated properly the v-band clamp connecting center section to exhaust housing can be tightened.

46. Connect the turbo oil drain line to the turbo.

47. With a syringe, pre-lube the turbo center section with oil via the oil feed port

48. Now install the supplied ¼” NPT X #4 JIC fitting into the oil feed port of the turbo with TEFLON PASTE.

49. Locate the turbo oil feed line and install from oil filter housing to turbo center section as shown;

50. Carefully install the compressor cover onto the center section of the turbo with the clamp.

51. Attach the turbo cover onto the cross over pipe with supplied v-band clamp but do not fully tighten yet. the compressor cover will rotate to give proper alignment to the cross over pipe. Ensure the pipe is evenly inserted in the boot at the factory turbo and then tighten the

compressor cover clamp, then the v band compressor outlet clamp and lastly the 3” T-bolt clamp on the reducing boot at the factory turbo.

52. Reinstall the battery.

53. The coolant tank overflow hose can be connected and routed down the fender well.

54. Install the MAF sensor from the OEM intake pipe into the new 5” intake pipe with the supplied 4mm screws.

55. Install the 5” boot onto the turbo inlet with both 5” T-bolt clamps followed by the intake pipe and air filter with pre-filter cover. Reconnect the MAF connector from the wire harness.

56. Install Turbo blanket onto the exhaust housing.

57. Fill with Coolant.

58. After first initial test drive be sure to recheck and tighten all clamps.

Any Questions, Comments, or Feedback?

Reach us by Email- sales@wcfab.com

Or the shop phone- 630-277-8239

Thanks for Purchasing from Wehrli Custom Fab!!