FASS

[bill_mary_matt]

Good morning guys,
Well my lift pump is leaking. (2001 Diplomate LE) I have read several posts here as well as other forums. (As many have stated the information you guys provide is invaluable). I have talked to FASS (knowledgeable tech named Scott). They have a new product (introduced in latter 2021) designed for “industrial” applications which list motorhomes as one of the applications. Scott recommended the “FASS Industrial Series 165GPH Diesel Fuel System”. The description states, “our Industrial Series Diesel Fuel System eliminates the need to purchase and install a dedicated fuel return line kit.” I expressed my concern (grilled him) on everything I have read on the need for running a dedicated return line (potential pressure differential ect). Scott was very patient/professional in explaining the engineering of this product line. It uses a ¼ inch return output that T’s into our existing ½” return. Another difference is the 1 million mile or 5 yr warranty. This product is designed for non-pickup truck applications where a long-dedicated return was needed. 
I’ll install a gauge sending unit on the secondary filter tap and run output to a dash pressure gauge. 
Probably install 6 port fuse block in battery bay.  i'm hoping to find an ignition wire source at the tow plug.

I’m trying to compile my material list in hopes of ordering everything upfront prior to starting the install.  I’m a little fuzzy on fitting sizes. 
Do any of you remember the size of the plugs that screw into the oem pump once the hoses are rerouted? 
What size fitting quarter-turn ball valve to the INLET of FASS for changing filters?
What relay do I order to plug into the oem lift pump connector? 
Thanks 
Bill 
2001 Diplomate LE

  

 

 

[Rocketman3]

On page 5 is my writeup on August 1st  

I found an ignition source in my rear run bay. One of the terminal blocks says “ignition”. I ran that to a relay and used the relay to drive a 6fuse block. 
 

I used AN10 coupling and 2 AN10 caps to couple the fuel hoses and cap the OEM lift pump. (I got them from Amazon - Evil Energy brand).

On my install I put the FASS where the first fuel pump was - I believe FASS pump sizes were the same as the old fuel filter housing. So I didn’t need any other fittings there. 
 

I didn’t put a ball valve on the inlet of the FASS pump for changing filters.  I just figure I will redo the initial start procedure- but it is a good idea. 

[tmw188]

EVIL ENERGY 10AN Flare Cap Block off Fitting Plug Black 2PCS

Aluminum Fittings 180 Degree -10 AN Female Flare Union Swivel Coupler Fittings Black 7/8-14 AN10 Thread Connector

10AN to 10AN Fitting Flare Union AN10 to AN10 Male Coupler Straight Fuel Hose Adapter Fittings Black 2PCS

EVIL ENERGY 10AN Female to 8AN Male Flare Reducer Adapter

SYKRSS 8AN 90 Degree Push Lock Swivel Hose End Fitting For Rubber Fuel Line Black

Auto Meter 2265 Metric Adapter/Oil Pressure

MEANLIN MEASURE 0~30Psi Stainless Steel 1/8" NPT 1.5" FACE DIAL, Glycerin Filled Pressure Gauge, Liquid Filled, Water Oil Air, Lower Mount, with 1/8" x 1/4" NPT and 1/8" x 3/8" NPT Hex Bushing

MEANLIN MEASURE 0~30Psi Stainless Steel 1/8" NPT 1.5" FACE DIAL, Glycerin Filled Pressure Gauge, Liquid Filled, Water Oil Air, Lower Mount, with 1/8" x 1/4" NPT and 1/8" x 3/8" NPT Hex Bushing

irhapsody 1 Pack 40/30 AMP 12V DC Waterproof Relay and Harness - Heavy Duty 12 AWG Tinned Copper Wires, 5-PIN SPDT Automotive Relay

This should get you started, you’ll need to configure your return fittings at the tank. 
I considered the Industrial pump but because of our unusual setup with fuel tanks being 30’ or more away I decided not to go with it. 

[jacwjames]

I guess FASS has done their homework on the return line issue to design one that you can install with a 1/4" return line tied into the 1/2" original return line from the CAPS pump.  Wonder why they recommend the 165 gph pump, considering the engine uses ~8-10 gph means the 1/4" will have to handle ~150 gph.  Seems like overkill to me and has to result in higher back pressure on the return line.   I guess I could dig out my Fluid Dynamics text book and try and calculate it but I assume FASS did that. 

I know you have talked to FASS about this but I'd want to confirm with Cummins that there would be an issue with back pressure on the CAPS pump.   When I got advise from VanWill on my FASS install he said he had talked to Cummins and at the time they recommended that a dedicated return line be used.  But this was with the old style pump. 

FASS warranty covers their pump but will not cover any issue with the engine if something goes south.   Just Sayin

[jegall]

[tmw188]

1 hour ago, jacwjames said:

I guess FASS has done their homework on the return line issue to design one that you can install with a 1/4" return line tied into the 1/2" original return line from the CAPS pump.  Wonder why they recommend the 165 gph pump, considering the engine uses ~8-10 gph means the 1/4" will have to handle ~150 gph.  Seems like overkill to me and has to result in higher back pressure on the return line.   I guess I could dig out my Fluid Dynamics text book and try and calculate it but I assume FASS did that. 

I know you have talked to FASS about this but I'd want to confirm with Cummins that there would be an issue with back pressure on the CAPS pump.   When I got advise from VanWill on my FASS install he said he had talked to Cummins and at the time they recommended that a dedicated return line be used.  But this was with the old style pump. 

FASS warranty covers their pump but will not cover any issue with the engine if something goes south.   Just Sayin

Yeah depends on the person you talk to at FASS like anything else they have their own opinion and then say the 100gph should work just fine. If I remember correct even though it hasn’t been all that long ago I used the 100gph pump. I don’t think the Ind Pump is no less work to install anyway.

[jacwjames]

21 minutes ago, tmw188 said:

Yeah depends on the person you talk to at FASS like anything else they have their own opinion and then say the 100gph should work just fine. If I remember correct even though it hasn’t been all that long ago I used the 100gph pump. I don’t think the Ind Pump is no less work to install anyway.

100% agree with that, depends on who you talk to. 

Back in ~1990 the mining company I worked for was getting ready to spend several million dollars on new drill rigs.  The supplier spec'd them with a smaller drill, they rated them in KW vs HP.  They gave a big presentation and everybody was excited buy I was skeptical.  Went back to my office and did a comparison on the rigs we were currently using converting everything to HP and the new quote was way under powered.  Went and talked to my boss and he told me to get with the purchasing manager and in turn arranged for another meeting the drill company rep.  We agree to buy the drill as spec'd but with guarantees as to performance.  Drills had to be able to drill a 12' hole in a set time.    Guess what, they couldn't do it had to refit the drill rigs with not only new drills but had to up size the hydraulic pump that powered the drill.   Good lesson for me as to not to just take salesman's gibberish as gospel.   Good lesson to the other managers also. 

[bill_mary_matt]

Tech said the 165 unit recommendation was to compensate for the 30’ pull from the tank. I  posted this to you guys to get thoughts/feedback before ordering one. I real appreciate your feedback 

[tmw188]

3 minutes ago, bill_mary_matt said:

Tech said the 165 unit recommendation was to compensate for the 30’ pull from the tank. I  posted this to you guys to get thoughts/feedback before ordering one. I real appreciate your feedback 

Yeah we are both pushing. 

[bill_mary_matt]

thanks for the parts list Todd. very helpful. 

[tmw188]

FYI educate yourself a little on AN and JIC fittings. I learned a little along the way. You will be dealing with sizes 8 and 10’s for your install. 8 is smaller than 10. Also be careful they are not the same as flare fittings. The angle on a flare is 45* and the AN/JIC are 37* NOT COMPATIBLE! 

[jacwjames]

19 minutes ago, tmw188 said:

FYI educate yourself a little on AN and JIC fittings. I learned a little along the way. You will be dealing with sizes 8 and 10’s for your install. 8 is smaller than 10. Also be careful they are not the same as flare fittings. The angle on a flare is 45* and the AN/JIC are 37* NOT COMPATIBLE! 

X2 on educating yourself.

I thought I had a pretty good background in maintenance but since joining the Monacoers.org and IRV2 Forums I have learned more then I thought I'd ever need to know on how to troubleshoot electrical systems. Still have a lot to learn.   Luckily I enjoy reading/learning new things. 

I am no expert but willing to try and help others and I know other members do the same thing. 

[cbr046]

I got my AN10 fittings from a hydraulic hose supply place with the advantage of being able to take fittings there and check compatibility, fit, etc. 

- bob