HPOP Hose/Line Replacement: Full Step By Step How To

HPOP Hose/Line Replacement: Full Step By Step How To

Dec 12th 2025

Full PDF Instructions can be downloaded here: https://www.riffraffdiesel.com/content/RESOURCES/HPOP_Hose_Replacement.pdf

Parts Link:

HPOP JIC Line - Driver Side Head 99-03: https://www.riffraffdiesel.com/hpop-jic-line-driver-side-head-99-03/

HPOP JIC Line - Passenger Side Head 99-03: https://www.riffraffdiesel.com/hpop-jic-line-passenger-side-head-99-03/

Recommended Tools: 

HPOP Quick Disconnect Hose Removal Tool 99-03: https://www.riffraffdiesel.com/hpop-quick-disconnect-hose-removal-tool-99-03/

 

1.  The HPOP hoses are fastened to the heads and the HPOP using special Eaton STC® quick disconnect fittings. These fittings allow the hoses to easily be removed using a special tool. The fittings and hoses are subject to pressures in excess of 3,000 psi. You must use the proper hoses and procedures to ensure system integrity.

2.  The drivers side hose goes to the forward fitting on the HPOP and the passenger side hose goes to the aft fitting. (fuel bowl is removed in the pictures for clarity. It is not required to remove the fuel bowl to replace the hoses)

3.  Clean the hose fittings thoroughly before disconnecting. This will reduce the likelihood that you will introduce contaminates into the high pressure oil system. 

4.  Insert the HPOP Line disconnect tool behind the release sleeve on the cylinder head fitting to disconnect the locking ring from the fitting. Pull the hose free from the fitting. 

5.  Install the new hose onto the HPOP fittings after inspecting the fittings (below). You will hear a slight click when the fitting engages the lock ring in the fitting. Test the connection by trying to pull the hose out of the fitting, it should not pull free of the fitting.

6.  Install the other end of the hose into the cylinder head fitting. Test it for positive engagement by trying to pull the hose out of the fitting as you did on the HPOP end.

7.  After installing the new lines the truck may start hard/slowly and run rough. This will get better after roughly 50 miles as there is air in the high pressure oil system. It will purge out while driving.

8.  Let the engine idle for 5-10 minutes, check for leaks. After idling, drive the truck and check for leaks. 

Eaton STC® Fitting Inspection:

Eaton STC® Fittings have an internal o-ring and back-up ring installed that should be inspected prior to installing your new hoses.

The o-ring and back-up ring should be free of tears or gouges. The orings seal against the barrel of the hose.   

The latch ring should remain in the fitting on it’s own. 

Special thanks to Ken (Woodnthings of FTE) for photos and instructions.