Conventional 2011-2022 Hino DEF Header replacement

Written By Mark Grigoryan

Photos and video coming soon!

Tools you will need:

SPL Tools DST-001

3/8’s Ratchet

12mm socket

14mm socket

12mm wrench

14mm wrench

Pair of cutting pliers

Long nose pliers

Hose pinch pliers

Small pick

Begin by making sure the vehicle is in park, ignition is off and the wheels are choked. Diesel Exhaust Fluid is very corrosive and should be handled appropriately. Wear personal safety equipment such as gloves and protective eyewear.

Step 1:

Remove the passenger side upper step by removing 4 14mm bolts. Bolt in the rear upper corner will need to be removed with a 14mm wrench to clear the rear of the cab

Step 2:

Remove the exhaust heat shield by removing 4 12mm bolts

Step 3:

Remove 3 bolts holding the cover to the DCU. Remove the cover and set it aside. Remove 3 12mm nuts holding the DCU to the upper bracket. Set aside the DCU.

Step 4:

Remove the DEF tank hold down strap by removing 2 14mm nuts. Remove the tie downs and the strap and set them aside.

Step 5:

Cut 2 zip-ties holding the lines to the DEF header. Remove the DEF header electrical connector by turning the locking ring counterclockwise. Set the electrical connector aside preventing it from being soaked in fluids.

Step 6:

Using needle nose pliers, slide the tension clamp off the coolant feed and return lines. Slide the hose off the tips of the DEF header enough to install the hose pinch off pliers. Slide off both coolant hoses completely. Wipe off spilled coolant.

Step 7:

Using a small pick, pry up on the locking portion of the DEF feed and return lines. Carefully slide off the DEF lines off the DEF header.

Step 8:

Pull the DEF tank out of the cage enough to be free of the lines attached. Wipe off any spilled fluid or contaminants from the top of the DEF tank. Keeping the DEF tank in the cage to keep it from rotating, install the SPL DST-001 tool on top of the DEF header. Use either a 3/8’s ratchet or a 22mm wrench to rotate the DEF header counterclockwise. Remove the DEF tank from the vehicle.

Step 9:

Remove the DEF header vent line and set it aside as it will be re-used. Remove the DEF header from the DEF tank. Remove and discard the sealing “O” ring. If the failure of the DEF header was due to foreign matter or wrong fluid, throughly clean the inside and outside of the DEF tank prior to installation.

Step 10:

Install the new DEF header with a new “O” ring into the DEF tank. Lightly lubricate the “O” ring with your choice of automotive lubricant. Position the cam lock tabs into the installation position. Install the SPL DST-001 tool onto the top of the new DEF header. Turn your choice of 3/8’s ratchet or 22mm wrench clockwise while pushing on top of the new DEF header to seat it into the DEF tank. Install the DEF header vent line.

Step 11:

Install the DEF tank back into the vehicle. Slide the DEF tank into the cage to meet with the lines.

IMPORTANT

Should the end of the DEF feed and return lines crystalize, DO NOT install them into the DEF header. Use hot water to flush the end of the lines prior to installation.

Step 12:

Insert the tips of the coolant lines onto the feed and return port of the DEF header. Once the lines are partially on, remove the hose pinch pliers and completely install the hoses. Re-install the tension clamps. Wipe off any spilled fliuds.

Step 13:

Route 2 new zipties through the clipped section in the DEF tank cage to re-secure the lines. Reinstall the DEF header electrical connector by matching the groves of the connectors, then turn the locking ring clockwise until it stops.

Step 14:

Reinstall the DEF header hold downs and the strap.

Step 15:

Reinstall the DCU by routing the studs into the upper bracket. Tighten 3 nuts holding the DCU. Reinstall the DCU cover with 3 bolts.

Step 16:

Reinstall the exhaust shield cover with 4 bolts

Step 17:

Reinstall the upper passenger side step with 4 bolts. Use a wrench to install the rear inside bolt to clear the rear of the cab.

Step 18:

If the DEF header was replaced due to DEF contamination or SCR related faults; use DX3 diagnostic software to clear “SCR related memory”. Verify with DX3 that the new DEF header reads quality, quantity and temperature to verify the repair. Run the engine, check for fluid leaks and top off the coolant if needed.

Mark Grigoryan