Buying Used and Getting Back to Basics

Over the course of it’s nine year run of production, International produced almost 2-million 7.3L Power Stroke engines for Ford. Yeah, 2-million engines for the 1994-2003 Ford trucks, most of which we’d dare bet are still out there chugging along. That big cubic inch diesel engine was a workhorse in it’s day and was of the big reasons the Ford Super Duty introduced in 1999 was so successful. We picked up this 2000 F350 this past year from the original owner with the intentions of building a solid daily driver, capable of doing just about anything we asked of it and so far, it’s headed right down that path. With what is not considered ‘low-mileage’ for a 7.3L truck, at only 165,000 miles she runs great but still needs some work in places.

After 20+ years on the road, it’s not surprising to have a few random leaks pop up on you every now and then. In the 1999-2003 7.3L applications, the factory fuel bowl is prone to leaking from time to time, especially around the rear drain valve. Riff Raff Diesel offers a complete Fuel Bowl Reseal kit that will give you every little O-ring you’ll need to completely seal this setup back up.
Obviously there is going to be some fuel lines you’ll need to disconnect, like this main return line right here in easy view/access. But be prepared to fight a little to get to the lower main feed fitting and the smaller cylinder head feed lines located on the lower passenger side of the bowl.

Most recently, we finished up the installation of new rotors and pads, upgraded the high pressure oil system and have even done the basic power adding package with an intake, exhaust and tuning from Edge Products. But even more recently than that, that diesel motor has done what the 7.3L was most likely best know for, leaking. While it’s common to leak some oil from a few places, this time the truck developed a fuel leak that took a little bit of time to chance down, but some diagnostics and the trail of diesel led us right to the engine valley where a steady stream of fuel dripped off the fuel filter housing.

The fuel bowl is mounted to the engine with two 13mm bolts that run through the front of the timing cover, but with the four fuel lines disconnected and the electrical connections undone (like the water in fuel sensor), removing those two bolts allows you to take the bowl right out of the engine valley to service on the bench.
With the fuel bowl lid removed, we could discard the dirty used fuel filter and start removing the factory fittings and hardware to be resealed. The kit from Riff Raff is as complete as they come and will replace everything on the fuel bowl, they also include new fuel line fitting seals.

Because the 7.3L Power Stroke uses a higher pressure fuel pump down on the frame rail, to pressurize the fuel system up to around 55-57psi, after 20 years of service, it wasn’t too surprising to find some of the fittings and O-ring seals losing their ability to seal. Since this is a fairly common issue on this truck, and there are still so many of them out on the road, Riff Raff Diesel took the time to develop a complete fuel filter bowl rebuild kit that includes every O-ring and seal you’d need to completely go through that filter housing. New sealant for a couple of the threaded fittings, new O-rings for the fuel bowl heater element and drain valve and all new seals for the flared hardlines that feed fuel in and out of the bowl itself.

The most common place for leaks on the fuel bowl is this drain valve located on the back side of the filter housing. The O-rings can harden and lose their ability to seal, so the Riff Raff kit uses a fluorosilicone O-ring here that ensures an excellent leak free seal for probably longer than the truck will last.
The sensor located next to the drain valve is the water in fuel sensor and the fuel heater, the kit includes replacement O-rings for both as well.
With everything removed from the fuel bowl, we decided now would be a great time to give it a full cleaning. The years of gunk and build up that had settled in the bottom of the bowl was rather disgusting and while some brake clean and a rag would probably do the trick, this was the perfect opportunity to use our new ultrasonic cleaner.

The Riff Raff Fuel Bowl Seal kit includes a total of 11 O-rings, including two fluor silicone O-rings developed specifically to replace the original yellow O-rings found on the fuel bowl drain valve, one of the most common places to leak on the filter bowl. The factory O-rings get hard over time and lose their ability to keep a solid sealing surface, so this inexpensive kit ensures no leaks, with a seal that will probably outlive the rest of the truck. The fuel bowl can be removed from the engine in 45-minutes to an hour with some simple hand tools and is simple to rebuild on the bench, just be sure to take your time and be patient as some of the fuel lines can be a challenge to reach with your combination wrench. We found that unbolting our air intake heater and glow plug relay bracket from the cylinder head really helped gain some access to the lower cylinder head feed lines.

After only 15-seconds in the ultrasonic cleaner and a simple soapy water solution, the fuel bowl came out looking like brand new both inside and out and we could start re-assembly with the new O-ring and sealant kit.
First up, resealing that factory drain valve. We had to use a small pick tool to get the hardened original yellow O-rings removed from their seat. The new O-rings fit perfectly in place and should ensure thousands of trouble free miles.

Since the factory fuel return parts were going to be removed, we also opted to upgrade the fuel system with Riff Raff’s simple Fuel Rail Crossover (FRx) kit, which replace the factory return fitting on the side of the bowl and allows the installation of two new fuel return lines to be added, eliminating the factory ‘dead head’ fuel system. The 7.3L Power Stroke uses one fuel line to feed each cylinder heads fuel rail that feeds the injectors. But these rails just come to a dead so unused fuel just stops when it reaches the end of the head until the next injection series can use it. This isn’t the most efficient setup, and the FRx kit allows you to replace the plugs found at the end of the fuel rails and install two fuel lines that return to the fuel bowl. This in effect completes the system so that fuel can cycle endlessly as needed, improving efficiency within the fuel system which equates to happier injectors, and a smoother quieter idle.

A seal often overlooked, but that can also leak easily if not replaced is the rubber seal found on the ends of each hard fuel line. These seals will be found inside the brass fittings, and you’ll have to fish around for a minute with a pick tool to slide them out from within the brass nut. Once the two are separated, you can remove the seal from the end of the flared fuel line and slip on the new seals from the Riff Raff kit.
Notice the difference in the two used seals on the left and the brand new seals on the right? The years and the miles have taken their toll on those originals, and if they weren’t already leaking it’s apparent, they weren’t far from it.
While the fuel system was torn apart, this seemed like the perfect opportunity to also do some upgrades like the Fuel Rail Crossover (FRx) also from Riff Raff Diesel. This simple kit allows the cylinder heads, which dead head from the factory, to return fuel to the fuel bowl to help quite down the engine idle and allow full circulation of any unused fuel in the system. They also include a couple different springs to allow you to adjust your fuel pressure from stock.

The kit also includes three different return springs for you to choose from, so you can change the fuel pressure, Riff Raff has found that upping the pressure from the factory 57-psi to 65-psi offers better performance and efficiency all the way around. This is an inexpensive kit that can really offer some solid benefits in engine run quality you’ll notice the first time you fire it up. Upon final installation of freshly rebuilt fuel bowl, we also made sure to install a brand new fuel filter and top it all off with one of Riff Raff’s billet fuel filter caps. This trick cap replaces the factory plastic style cap that is prone to cracking and stripping when trying to service the fuel filter, plus it adds a nice look under the hood.

The FRx block installs right in place of the factory return fitting located on the driver side of the fuel bowl. The factory return line will thread right in place, and two new fuel lines will be added to the system. One running from the back of the driver cylinder head and one from the front of the passenger head.
This shows where the new Riff Raff FRx fuel line is routed into the driver side cylinder head. The factory fuel rail within the head normally just dead ended here, but removing the factor plug and threading in a new AN style fitting allows that fuel to now return to the bowl. This offers better injector performance and a quitter, smoother idle from the engine.
With the fuel bowl reinstalled and the FRx added to the system, we finished it all off with the billet fuel cap that Riff Raff produces as well. The factory bowl uses a cheap plastic style cap that can be prone to cracking or stripping when trying to service the fuel filter. With the billet cap, we not only have a sturdier reusable lid, but it looks good under the hood too.

With our fuel leaks taken care of, we also spent some time this month upgrading the exterior of the truck with some new headlights and turn signals to replace the faded and foggy factory units. The original amber cab lights were replaced with some smoked lenses and LED bulbs and finish off the total look, we replaced our faded and cracked mirrors with an upgrade kit from KT Performance. The factory mirrors obviously serve their purpose, but in 2008, Ford updated the styling of their mirrors with some that were slightly larger and offered a much better blind spot mirror that really helps in driving a big school bus like our crew cab long bed around.

Moving to the outside of the truck it was time to do something about these faded out mirrors. The glass on one side has a hairline crack in it, they shake while driving, and the plastic just doesn’t clean up anymore after 20-years of sun oxidation.
A very popular upgrade for the 1999-2003 application is replacing with the newer Super Duty square styled mirrors found on the 2008+ models. Ford switch mirror designs that year and the glass offers a much better field of view, in the main mirror, but especially for the lower blind spot mirror. KT Performance offers a complete 99-03 conversion kit that offers a bolt-in mirror that will also plug right into your factory connectors using their supplied adapter harness.

KT Performance offers this mirror with smoked turn signal lenses that looked great with the other upgrades we had made to the truck, so they are not only functional, but really update the look to. While the new mirrors use a different style wiring connector, KT made that easy by including a simple wiring harness adapter, so this is a complete plug and play install. We should mention however, that while our powered mirror functions still work, because our truck wasn’t originally equipped with marker and turn signals in the mirrors, we don’t have the wiring in the doors to support that function from the new mirrors. So, if you plan on getting those turn signal to work in a 1999-2003 truck, plan to do some wiring and tapping into your factory turns somewhere. All and all, this is a super simple job that requires door panel removal but can be accomplished in about an hour total for both doors.

Swapping out the mirrors is quite simple and can be done in less than an hour. You will need to remove the door panel to gain access to the wire connector which is located behind the door speaker. The mirror is attached to the door with four bolts hiding behind the upper plastic trim piece and a couple rubber grommets.
With the door panel removed, you can remove the four small bolts holding he speaker to the door and set it aside. Directly behind there you’ll find a round white plug running from the mirror, this harness is what powers the adjustable motors. The new mirror kit from KT will allow the motors to function as stock, but if you want the new mirror lights to work (turn signal/marker) extra wiring will be required as that is not a feature that was originally equipped on the 1999-2003 models.
The top while color connector is the original connector, the black squared connector is what is used on the new mirror, so to adapt these two plugs together, KT Performance includes this short harness that allows this swap to be complete plug and play.

The new suspension lift we installed from BDS is working out really well and we’ve loved the way these Anthem Wheels pop against the somewhat haggard white paint. The Toyo A/T3 tires have been extremely impressive in the snow we encounter all winter long and offer no road noise whatsoever on the freeway, at least not that we can hear over that clacking Power Stroke under the hood. Next month we’ll be doing some steering upgrades with a Blue Top gearbox, and we plan to tackle a turbo and exhaust up-pipe job in the near future as well.

The new 2008 style mirror not only offers better visibility for backing up and checking blind spots in traffic, but they also look really good on this old truck. The smoked lenses also ties in nicely with the smoked cab lights we’d installed just a few months prior.


Riff raff diesel

Kt performance


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