The Ford YC3Z-9J323-E and YC3Z-9J323-F are the OE high-pressure oil lines from the HPOP to the heads on a 1999–2003 7.3 Powerstroke. This is the pair. E is the driver side. F is the passenger side.

These hoses crack and weep at the fittings, which dumps ICP in the valley and shows up as a hard start. Ford’s later lines are the ones to use. The driver line is a 90-degree fitting at the pump and a straight fitting at the head. The passenger line is 90 degrees at both ends and supersedes YC3Z-9J323-DA. The F line also fits an early-1999 passenger head, so the older hose is not required. The fittings in the pump and the heads are not included. If those are chewed up, the new hose will still leak.

It fits 1999–2003 Super Duty and Excursion 7.3 trucks. A 1994–1997 OBS uses a different line set.

Fitment

• 1999–2003 Ford 7.3L Powerstroke
• Driver line YC3Z-9J323-E
• Passenger line YC3Z-9J323-F
• Genuine Ford
• Lines only
• Does not fit 1994–1997

Replace both sides. A new hose on a damaged fitting will not hold. The O-rings for those fittings are in the DieselSite HPOR set.