There are several FASS and AirDog references on IRV2.com. This is one link that talks about my 2004 Itasca Horizon with a 2003-ISC-350-CAPS and a Freightliner chassis that will give you a good idea what's involved.
https://www.irv2.com/forums/f123/cum...mp-458337.html
Your installation will be slightly different if you have a 5.9L, but the principles are closely the same. I.e., you want to add a FASS or AirDog you do this to provide positive fuel pressure to your injection pump; and that will insure adequate fuel flow; to provide adequate cooling and lubrication to the injection pump; which in turn is supposed to prevent premature injection pump failure. (Costing you $5,000-$9,000 if you blow your ECM at the same time. TBD.)
Note: In the picture below you can see your Lift Pump is different than my ISC lift pump and a CAPS injection pump. Also, HPCR (aka CAPS-II) used in 2005-6 coaches; and the 2007+ HPFR systems have different lift pumps and plumbing.
Installations Notes for 2003-ISC-350-CAPS & Freightliner Chassis:
* I went with FASS because I liked that it was returning a lot of fuel to the tank. This "fuel polishing" cleaned up my algae problem in 3000 miles. (AirDog would have taken 30,000+ miles to recycle the same amount of fuel, but an AirDog installation is slightly easier according to some.)
* My Freightliner fuel tank does not have easy access on top to T-in a return FASS fuel line; So I cut a section out of the driver's side filler neck and inserted a 2" Yoke (a "Y-fitting" you order separate because the FASS kit comes with the blue colored 1-3/4" Yoke). The installation was not hard to do; and I reused the OEM rubber to connect the fuel fill pipe by cutting it in half; and with a couple hose clamps I was good to go.
* I also did NOT by-pass my Lift Pump Manifold like most people will tell you to do, because I already had 2 filters installed and it was easier to just leave the fuel lines as-is. All I did is this: Remove the #1 (primary filter) and insert the FASS Pump in it's place. And now with over 10,000 driving miles on my FASS pump I have no reason to believe you need to by-pass the lift pump manifold. No fuel will run through your lift pump with the electrical disconnected. And you can't by-pass the lift pump manifold, but if you want to remove unnecessary fuel lines you can. It all depends on your current setup: Do you have 1 filter or 2?
* Now my FASS pump has 1 suction filter and then a second filter with +15-18PSI. My FASS pump then sends positive fuel pressure to the lift pump manifold... and then to the #3 filter... and then fuel travels to the CAPS injection pump.
* I now use a 20-micron filter on my #1 suction side; a 10-micron filter (with WIF sensor) for my #2 FASS Filter; and a 3-micron filter for my #3 Filter.
Note: You don't want to go smaller than 20-microns on the #1 suction side FASS filter port. And FASS is very particular about the return fuel line. I.e., you want to make sure there are no sharp bends and that it is 1/2" in diameter. (You also can order fuel hose, the 2" yoke, and fuel fittings direct from FASS but you have to buy your FASS kit from one of their Dealers.
* FASS requires a 1/2" fuel return line to the tank, but AirDog does not, because it spits out so little return fuel. So some owners tap into the CAPS fuel return line just behind the Lift Pump Manifold so they do NOT have to run a long fuel line back to the fuel tank. This is simpler for some I guess, but running the FASS fuel line back to the tank filler neck is no big whoop either!
* FASS is a "constant volume" pump vs. AirDog which is a "demand flow" pump. Both are very good and reliable. However, if you don't mind tapping into your fuel filler neck and don't mind running 38' of fuel return line, I would recommend the FASS over the AirDog, but that's like saying I prefer Ford over Chevy, which I do as well.
* As for your lift pump wires: YES! You need to disconnect them and insert a relay to fool the ECM into thinking it is connected to your lift pump, but it's not. Otherwise, you will get a "check engine light" on your dash.
FINAL COMMENTS:
If you have a lift pump like my ISC-350-CAPS (see diagram below) then you probably need to check/tighten your 3 lift pump bolts every 20,000 miles or so. This is a must for every CUMMINS-CAPS owner; and don't be surprised if you find them 1/2-3/4 turn loose on your first inspection (50,000 miles or more). This is a very important and a very, very neglected preventive maintenance step that Cummins does not even do unless you ask. (You need access from the top of your engine.)
MORE DO DADS:
To top off your FASS or AirDog installation, you can also and a GlowShift Digital Pyrometer/EGT and a FASS PSI gauge. Both are about $150 each and then.... if you been a good boy this year... you might ask Santa for an Ag Diesel Power Module!!! ($700)
All if these upgrades can be installed by an owner with average mechanical abilities and you don't need special tools. ...Just knowledge and patience. ...Or I would go to any Diesel Performance Shop that has installed a FASS and ask them if they will work on your RV. It will thank them 8-10 hours. It will take you 2-3 days, but it's a relatively fun project, providing you have your fuel line connections all preplanned.
Note: You can also pre-install your FASS and then take your RV to the shop and let them finish the job if you get stuck, but I'm guessing if you take this project one step at a time you will be okay.
* FYI, you also need a key-switched-12V-power-source for your FASS or AirDog; and I found mine by tapping into the pink wire to my tow harness connector. You can read about this in more detail by going to the link posted above. ...And good luck with your project. Please take pictures for other people to see.
Linear Mode
