gglenn

That key did the trick, thanks.

Curious if they broke out the cost of replacing the lift pump and rocker box gasket. Just curious what the lift pump replacement cost was...

Install picture, attached! Mounting AirDog was the easy part of the install, the new hoses, fittings, and wiring took the most time. Recap: Mounted AirDog in the trans cooler/vented side door, Road side, just behind rear axle. It's a busy bay with hydraulic jack pump/hoses and Air bag control unit. Mounted Airdog pump in place of Monaco relocated Fuel/Water separator. Plumbing: Right side (Inlet) of AirDog is from Tank (stock nylon/hard fuel line/funky brass quick connect), small Blue/Red fitting just above is a new hose with "separated air" and it returns to Tank. Black fitting on left side of Airdog goes to back of engine fitting (normal port). Left side(Inlet) of stand alone Secondary filter is coming from Gear Pump portion of engine mounted pump, Right side (outlet) returns to High Pressure inlet of engine mounted pump. Excess fuel return (at back of engine) to tank was left stock (stock nylon/hard fuel line). Hoses from back of engine to ECU cooler and ECU cooler to Gear Pump inlet described in previous posts. Stock lift/prime pump (behind ecu cooler) removed. PS If you notice the WIF connector unplugged, I'm swapping AD supplied water separator with FG/Cummins water separator filter that has WIF sensor. The FG/Cummins filter will be FG19596, which is a finer Micron than the normal FG1003. AirDog_Done.pdf

Happy Holidays to you all. Prime Rib..oooo

Lift pump was likely not wet, but can't confirm it was the only problem. I suspect the fitting going into ECU cooler didn't help the whole situation either, since it's also one side of the lift pump connection point, given it is also check valve, small size passages, just very restrictive setup. Other ECU cooler port is similar but no internal check valve. Both fitting were removed/upgraded along with lift pump removal, so no longer a problem. Will do on photo's, first test drive will be up and down our long driveway a few times. Yes, was shooting for dependable vs. it works.

Tow to Cummins, cost? Cummins troubleshooting bill, parts? Many have paid $$ just to replace the bad lift pump that may end up in the same state down the road. Many have driven off from Cummins/Alternate shop with the same problem they started with, back to shop. Guessing between a tow, and Cummins bill I'd have spent even money at this point. Although, more of my time. And Cummins fix, would not include the AirDog.. The AirDog and FASS systems are put on thousands of Diesel, so not sure why the why. Sorry restated multiple times what I have done with hoses. The Tank to AirDog is stock, it is hard nylon hose. All the rest have been replaced with new. AirDog removes any induced air, so it would mask a leak in that nylon hose now that system is revised. Some may think this solution doesn't work. The coach is running and staying running with new Airdog all done, it did not stay running prior. I have always said it is a CAPS II, folks keep asking if it's CAPS which is not CAPS II. Concerning higher psi, stock gear pump output is around 20psi at idle per cummins doc, AirDog is set the same, albeit it would put 20psi on Inlet of Gear Pump, but not higher as "Manholt" states above. Once above idle stock gear pump and fuel system pressure increase, so not completely sure what prompted the "much higher pressure" comment. But do concede 20 psi at Inlet of Gear Pump vs. stock design which Inlet is in vaccum. If your pump is the same as the one I attached from the remanufactured pump company that says CAPS II, it only has a single high pressure output to the common rail, ie Not 6 separate line outputs. Sorry, Pic above does not show your pump.

I finally read thru much of your fuel pump install, looks great. I'll likely add an electric Dash Fuel Press. Gauge, sensor downstream of last filter and also add a pyro gauge. Tank cooling maybe... funny thing is previous owner added a Raptor inline pump for generator at almost the the same spot as your install. Didn't know it was there until my AirDog line routing exposed it, always thought it was the vacuum pump I was hearing. Could easily split Raptor flow in parallel to cooler/fan and good to go. Was actually planning on creating a parallel loop back to the tank with the Raptor for Fuel scrubber, using the Secondary Fuel filter I removed with AirDog install. Previous owner Raptor install had no filter, just one in Gen. Thinking would be great to circulate fuel during long periods of tank sitting, during refills, and for mixing fuel additives if I'm not driving coach soon. Raptor is in similar tank location to your pump install, so super easy plumbing changes compared to AirDog install.

As we say...Clear as mud! Obviously we have various fuel "pump(s)" versions on our similar engine, so yes it's a bit confusing between the three of us. Yes, it is possible that my AirDog could cause pressure related problems/failure in either the Gear pump or the high pressure pump. I'm betting not, time will tell. As I stated in other post, I believe the biggest pressure impact will be at idle, once off idle pressures after gear pump will likely be similar to the stock system. As far as the fuel flow picture and sections I posted, it's accurate other than the relocation of the filters by Monaco. ISB Lift pump relocation document was in my quickserve area. The main issue for stock relocation was to get it off the engine, I was just referencing a common problem on the ISC, but document shows title as ISB, so guessing same issue on both. The check valve I removed may cause drainback, or loss of initial pressure when engine is off, but when engine is running it served to isolate/separate the lift pump and ECU cooling loop and likely stop drainback. If I have problems with drainback/hard starting I will add an inline check at the AirDog IN port, easy addition in my setup.

Just to confirm I'm not looney, these guys that sell reman. pumps call it CAPS II.. You can see the two red shipping caps on the bottom area, this is the Gear Pump IN/OUT. Harder to see the single High Pressure out port, but it's up top. I believe I never stated I had a CAPS setup, tried stating CAPS II. Seems everyone wants to lump them into being the same design. CAPS II.pdf

In Quickserve for my engine S/N they call it a CAPS II. Seems no one can tell me if CAPS II is really just another name for High Pressure Common Rail. I must assume with HPCR that each injector get the high pressure from the Common Rail Fuel manifold vs. the older style that has pump supplying high pressure separately each injector. My pump DOES NOT have 6 individual high pressure lines to each injection. When I was getting filters at Cummins NW, I asked the parts guy about that Pump when he was in QuickServe and he commented that I had the better pump design. Other versions were more problematic.

Nope not that one either, mine does NOT have 6 individual ports for each injector, see MyPump.pdf above.

Looks like this, attached. MyPump_CAPS II.pdf

Not that one, mine does NOT have 6 individual ports for each injector, I had it in an earlier post attachment. Attached again. Picture comes from my engines quickserve docs area Cummins_AirDog_CAPSII_ECU.pdf

Something like this would be good for engine area SealedRelay.pdf

I like it! Thanks much. I may just create a short lead off old lift pump harness, add Relay and zip tie it down at existing location. If any problems with it in the future would be more obvious (no wire tracing) troubleshooting. Likely I can find a sealed Relay setup.