Fuel return/ how important?

[coldtaco]

My 1985 HJ75 Ute didn’t come with a fuel return line. I installed a 12HT and it has a return line. Right now I have it T into the fuel feed line to the pump. I know gassers and HZ and later engines all have fuel return lines, guessing the HJ61 did too but don’t know. I sources the two fuel tank switching valves, feed-return. What are the benefits of any of installing this fuel return? I’m guessing part of the reason for the fuel return is to return the warmed diesel to the tank to cool it and therefore provide cooler fuel to the pump, but just guessing. Yes, I know my fuel pickup tubes only have a supply tube so something will need to be done to provide a fuel return into the tanks. Thanks

 

[rick_d]

Fuel lubes and cools the pump. Put in a return back to tank. A fairly large volume goes thru. Return should be 8mm at a minimum.

 

[duncanrm]

The 2H copes just fine without a return.. and 90% of the pump is identical to the 12HT. Reportedly the 12HT is easier to bleed with a return but beyond that I'm unconvinced of the value of a fuel return for the 12HT.

 

[rick_d]

Well 13bt’s, 1hz, and all the turbo 6 cylinders post 1990 have returns.

 

[duncanrm]

Well 13bt’s, 1hz, and all the turbo 6 cylinders post 1990 have returns.

All of these vehicles have rotary pumps as well, not inline.

 

[rick_d]

13bt is inline. At least my 1987 was, factory JDM truck.