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.

Jleamont, Just read your second post about Relay trick. So, you have no constant 12v on the Power side of relay and are using the Lift pump +12v to "fake activate" the Relay or are you using the lift pump +12v and -12v on the Power side of relay? Hopefully asked that properly. Wiring schematic sketch?

Sorry we had some discussion in Private. So to catch you up, AirDog is now installed in place of remote Primary filter, AirDog has Primary/Secondary on it, all stock lines and fittings after it have been replace with 12mm to #8JIC, Push on style #8-1/2" JIC fittings/hose used. 5 separate hose sections replaced. Stock secondary filter after Gear pump still in place. Stock hard Nylon Tube from Tank to AirDog left as is. Stock lift/prime pump behind ECU cooler removed, was in parallel loop with ECU Cooler. AirDog is now lift/prime pump, running always vs. 30 seconds. Reading in service documents Gear pump outlet in stock setup is about 20 psi at idle, Airdog pressure set similar, which yield same 20 psi pressure at inlet of Gear Pump). Stock Gear pump inlet would normally be in a vacuum (10" max), less vacuum good, more than 10" vacuum bad. AirDog puts Gear Pump inlet at approx. 20 psi. vs. in a vacuum. Once engine RPM is above idle Gear Pump pressure increases, approx. 70psi at high idle, more psi higher RPM. High Pressure pump is after all this. It's running great now, but a real road test and time will confirm if the upgrade was worth it. AirDog is easily serviceable and I have a dummy light for low Fuel pressure, no more guessing. I may add a Fuel pressure gauge, so I know exactly what is going on with pressure as Filters get dirty, under load pressure, etc.

Hopefully Cummins will have some great info. Thought I would chime in and try to contribute. Wolfe10 and DickandLois gave me much great input on figuring out my fuel system on my 04 Monaco Diplomat and an AirDog upgrade I just completed. Anyway your stock fuel path should be similar. Tank, Primary/H2O filter, ECU Cooler/Lift pump, Gear Pump In/Out (Sucks (HG) fuel from tank), then Secondary filter, finally high pressure pump inlet. So, my question is which filter had metal? Guessing it must be secondary filter that had metal. Anyway the likely culprit would be the gear pump. Seems to be a fairly easily serviceable/replaceable pump if bad. Secondary filter should be 2 micron, so high pressure pump hopefully OK. One last thought, hopefully not the problem. I believe any extra fuel from high pressure rail does return to the fuel inlet block/manifold at the back of the engine, recycles in before the ECU Cooler/Lift pump. So, metal could get cycled back thru system from high pressure pump, this would show up in the secondary filter

OK, Finally got this project finished up and need your thoughts on a ECU code. So, the stock "lift/prime pump" has been removed from the system, so connector is disconnected from ECU harness. The Engine code is 2265, which is Lift Pump High/Low voltage. So, ECU is expecting a load from lift pump for 30 seconds and doesn't get that. So, any thoughts on a Bypass harness. Maybe will need ECU tweek if possible.

Thanks for the info., ordered a couple E-3-5-15..

Back to defining differences between CAPS, CAPS II, and HP..systems in terms of # pumps involved. To restate: My CAPS II stock is lift/prime pump, gear pump, and then high pressure pump. Redone is AirDog II4g, gear pump, and then high pressure pump.

Had this on a personal thread but thought I would share, hopefully may help others. My system is a CAPS II, which has a common rail for high pressure fuel, ie the Gear/High pressure pump does not have 6 individual lines to each injector. Coach has a Cummins ISC 8.3L 330hp questions, (Engine S/N 46386599), , quickserv info. for my specific engine says it's a CAPS II. So, I've edit my original post into more of a statement than a question, please see later post with Cummins Common Rail fuel flow info. attachment Having some recent stalling/engine stop, no start problems. Luckily it was at the house! Many online, say it's the lift pump! None of the forums describe if the "lift pump" is the what I consider the prime pump or possibly the "lift pump" is a section of the CAPS II pump. Anyway, trying to "fix" this myself and decided to ADD an AirDog II 4G into the equation and remove the prime pump behind the ECU cooler, could be a good plan or possibly unnecessary. Figured it was cheaper than a tow and a Cummins bill. AirDog is basically a inline pump with it's own primary/secondary filter, and also removes "air" from Fuel, no magic magnet thou. Fuel flow: (Please reference attached pdf file with pics) Line 1: Tank to AirDog in side compartment on RV, Monaco relocated both Primary/H2O separator and Secondary to side compartment. I chose to put AirDog in place of the original primary. Line 2: Airdog to rear of engine fuel manifold/port Line 3: rear of engine fuel manifold/port to ECU Cooler Port In Line 4: ECU Cooler Port Out to CAPS II (Gear Pump!), #19 on diagram Line 5: CAPS II (Gear Pump!), to Secondary filter Line 6: Secondary filter to CAPS II (High Pressure portion), into #16(#2 port). Fuel returns from rail to back of engine fitting/ fuel manifold to enter into fuel inlet flow/return to tank. I've removed the prime pump (only ran for 30 seconds on key on) that was behind the ECU Cooler (see below), it was plumbed in parallel with the ECU cooler. I believe it's stock purpose was only a "prime" and then after engine was running, fuel is "sucked" thru fuel system via. CAPS II (Gear Pump!), . Since adding AirDog, I figured it was unnecessary and also had a check valve (ECU Cooler IN) that caused issues for some. Removed Check valve also. Hopefully I don't have hard starts without check, AirDog hopefully offsets that issue. PS 5 separate hose (Line #2-#6) sections with 12mm to Push Type 1 connector, Push Type 2 connector 2, and Banjo fitting have been replaced with 12mm to #8 JIC male end and #8-1/2 hose/fitting. Old hose was a mix hard plastic, some was rubber. DickandLois Reply: Gglenn, Just took the time to look at threads that cover you engine and some fuel issue. You have been reading the, but the second link is in a different thread first one and might prove helpful. http://community.fmca.com/topic/7186-cummins-isl-and-isc-engines-with-caps-fuel-injector/?page=2 http://community.fmca.com/topic/9625-cummins-caps-system-redesign/ I will be reading your information over the next few days to see what might be helpfull. Rich. More from me. He's doing something very similar to my plan other than he is putting the pump up front at the tank vs. just behind the rear tire bay in my plan. So, my plan AirDog will have to work "harder" in a prime or filter change situation, but it's also designed for a tough life. Much more robust design than the stock "lift" pump. Diagram shows the 2 separate "pump" areas in the single unit, the plumbing runs to in the CAPS II pump; ie one IN/OUT (7, 9 in diagram), (This is the Gear pump) which is also before the secondary filter and one IN to the high pressure pump unit at the end of the fuel loop (11 in diagram), after secondary filter. (This is the high pressure pump) 13 is the high pressure out to rail. The lift pump is a separate unit, runs for about 30 seconds on key on, I will call it a prime pump. So, the stock pumps are Lift Pump, Gear Pump, then High Pressure Pump. Lift pump is the small cylindrical pump behind the ECU cooler, Gear pump and High Pressure are in the same upper unit. Found these attached pics on quickserve. Gives the Fuel Flow path on the standard cummins config, obviously this gets tweeked when placed in the various coaches. Diagram is hard to read, but the text (see attached) shows each part of the fuel path. DickandLois Reply: The Diesel fuel is used to cool the injector pump, so more fuel is supplied then used. The Fuel tank acts as a heat sump, that removes heat by spreading it out in the fuel before it is recycled through the engine again. NOTE ! As the fuel is used the ability to cool the fuel is always decreasing. The key to maximum fuel economy is a fuel tank that is half full in hotter temperatures. Cool fuel increases MPG what pressure range? Do not work around a diesel engine with a possible high pressure leak when running. Clean the area well, start the engine, stop after a few seconds where is the area wet with fuel - that is the general location of the leak. The pressure are high enough to cut off a finger or kill if the wrong area is exposed to these pressures. Cummings engines, deliver around 18,000 psi of pressure. The Bosch VP44, which is able to produce 23,000 psi of pressure. *In today's diesel engines, fuel leaves the injector at 30,000 psi. Note. The ISC fuel return line(s) run under the valve cover and do leak at times, this will make the engine appear to be making oil as the fuel mixes with the engine oil. Not Good !! ISC is a real good engine over all, but like I said it does have its weak points. PS 5 separate hose (Line #2-#6) sections with 12mm to Push Type 1 connector, Push Type 2 connector 2, and Banjo fitting have been replaced with 12mm to #8 JIC male end and #8-1/2 hose/fitting. Old hose was a mix hard plastic, some was rubber. Good plan - the OEM hoses do not like the Bio fuels. Keep all in the loop, Rich Cummins_AirDog_CAPSII_ECU.pdf Cummins_CommonRail.pdf Lift pump move.pdf

I'm the second owner on our 2004 Monaco Diplomat, I never got keys for the side bay door that has the vent for trany cooler and access to the two fuel filters. They look to be a round key, like some bike locks. I just take the nut off the back when changing filters, but it's getting old. Thanks.