I am sure this has been covered, but I was thinking about installing a Carter 4601 as a pusher in series with the factory lift pump. My question is - what if the pusher goes out? Would the pressure drop to zero? Has anyone plumbed some sort of bypass in case this happens? My factory pressure is down to 5 at WOT, cruise is at 9 tp 10, idle 12 to 13.
I would love to get a RASP or FASS II, but the cost is too much at the moment. The Carter is $90 and plumbing and wiring should be no problem mounting it back at the tank.

Any ideas or suggestion?

 

Thats the exact set up I did prior to going with the FASS when I installed the twins. It worked great for over a year with my week LP 6psi@WOT I only changed it thinking I was pushing the envelope with the factory stock lines and my mods. The Carter pusher with the factory LP gave me a solid 17-18psi

 

Ya, if the pusher pump goes out, the pressure drops to between 2 and 8 psi, depending on which way the pusher's impellers are turned when they stop.

I have a Holley Red inline with my stock LP. I plumbed a bypass using Y-connectors and a simple ball-valve. The Red itself has an incab on/off switch.

Ya, I'd have to reach under the truck to turn the lever if the Red ever died. But... simple and cheap, right?

 

When you ran the wiring to the pusher, did you run it off of a relay and then trigger the relay from the factory harness? Sounds pretty simple. I assume a in-line ball valve cutoff could be picked up at Homed Depot or the likes.

 

Yes on the relay

 

Well this morning I saw pressure of 3.8 to 4.0 so I am going to have to do something immediately. So I ordered a new lift pump, 3990105, from a local shop. The cost was $162. I am going to call the dealership and complain since I had the truck in for surging under load and they said they drove it and didn't notice any problems. I asked if they noticed the fuel pressure and they said 5 was ok. I asked them to do the flow test and they said there was no need....
I tried to explain with a 9,000 lb camper, the pressures were low. Oh well, better safe than sorry. I will keep my current pump for a spare. I am still planning on adding the carter as a pusher when I get downtime.