// Install guides
REASSEMBLY — 17-19 DURAMAX 6.6L L5P
Putting a 17-19 L5P back together after the EGR delete, with or without the down pipe: the remaining coolant lines, the Y-bridge, A/C compressor, intake horn and intercooler pipe, the 9th injector plug, and the coolant refill. Torque specs: Y-bridge block off plate 25 ft-lb, Y-bridge bolts 89 in-lb.
Steps
1 Cap the unused port on the turbo coolant supply line
Use the supplied 1/4" silicone cap and hose clamp on the no-longer-needed port on the lower supply line to the turbo centre section.
If the turbo did not come off, unbolt the upper return hardline and refit it upside down so the pipe faces down; it routes the supplied coolant line in a later step much better.
2 Fit the heater hose assembly with the quick-connect and 1.3" aluminium barb
Clip the quick-connect onto the heater core fitting on the firewall, and push the barb end into the hose from the thermostat housing next to the turbo, using the OEM spring clamp left in place earlier.
3 Fit the 15" long 3/8" coolant line to the upper turbo line
It goes onto the upper turbo coolant line with the OEM spring clamp. The brass barb end connects to the OEM coolant line that tees into the coolant tank hose near the battery.
4 Fit the Y-bridge block off plate
With the supplied 8mm flange bolts and gasket. Torque to 25 ft-lb.
5 Refit the Y-bridge
Take the shop rags out of the intake runner ports first. Torque the eight 10mm bolts to 89 in-lb.
6 Bolt the A/C compressor back down and refit the serpentine belt
7 Refit the bale connector bracket and route the harness back
Reattach the bracket to the top of the compressor and run the harness back across the intake runner, reusing the Christmas tree clips where they fit.
8 Refit the turbo intake horn
9 Reconnect the hot side intercooler pipe to the compressor outlet
Tighten the clamp.
10 Locate the 9th injector billet plug
It is in the hardware bag.
11 Remove the 9th injector and fit the billet plug
Under the truck on the passenger side inner frame rail is the 9th injector on its mount, with a hardline across the crossmember to a quick-connect on the driver side frame rail just in front of the fuel cooler. Remove the injector mount bracket and the clips holding the hardline to the passenger side of the chassis. Slide the yellow clip on the connector by the fuel cooler sideways, press either side of the connector to release the hardline, fit the billet plug, and slide the yellow clip back to lock it. The photos show the removed assembly and the plug installed.
12 Refit the radiator drain plug and refill the coolant
The coolant tank cap is reverse thread.
13 Refit the intake assembly
14 Refit the fender liner
15 Start the truck and check for leaks
Give it some idle time first. It may take a few heat cycles before the coolant system burps all the air, so you may need to top off the coolant once or twice.