1989 P30 fuel line configuration at tank?

[Rover71]

Good AM--Jan02 2016--Happy New Year--
My 89 Itasca has the two line configuration in fuel tank sender/pump unit.
Just wondering if anyone knows where the smaller 1/4 inch one comes from ? i?? Don't think it's generator feed ,as it goes to the bottom of the tank.Don't  have generator, but compartment is wired & plumbed for it .
I've managed an access hole thru the floor to check for a clogged strainer/sock, just waiting for the new one to arrive before pulling the unit.
Thanks for any replies---Harv

[DaveVA78Chieftain]

Return line from mechanical fuel pump

[Rover71]

Thanks,Dave---I thought it should be, but earlier on I had disconnected that line at pump and blew back thru it, just seemed to hear air coming into tank without bubbling?
Maybe the tank was too low, but I got 8 gallons out when I drained it. Anyway, I 'll check it the same way after disconnecting the sender , got about 20'  of plastic IV line , works well for doing things solo.
Have a nice day---Harv

[DaveVA78Chieftain]

Like shown in this picture, the return line stops at the top of the tank just under the attachment cap

[BrandonMc]

And the half inch rubber hose, which is really hard to get to, is a very short 10" run to the fuel pressure regulator (which I hope NEVER goes bad, since its on the opposite side of the tank and would require dropping the tank to replace...and from the regulator right to a steel 1/2 line which runs all the way to the front mechanical fuel pump.

edit: I just found this thread discussing the following question here:
http://www.classicwinnebagos.com/forum/index.php?topic=12390.0

Has anyone tried to replace this hose you mention? The guys at the auto parts shop don't know what to do with it. Mine is dry and cracked, and since the RV vapor locks, every single source of potential air introduction is being absolutely eliminated. I have a 60gal tank. The brake line is also being replaced while access is open while the tank is dropped.


HI PRESSURE HOSE
GM PART NO.:
15530451-40 GAL.
15530401-60 GAL. 

[Rickf1985]

If all else fails take it to a shop that makes hydraulic lines and they may be able to male you one. Even if you can find on with the right ends on it you can cut it and insert a longer piece of fuel injection line with double barb fittings and clamps. The in tank pump only puts out 10PSI max so you are not going to blow the line apart.