Fuel Return Pressure

[abfiegen]

What is the fuel pressure in the return lines? This obviously varies with RPM and how far the pedal is depressed, but can anyone get in the approximate ballpark for me? The reason I'm wondering is because I am getting some hose fittings for my fuel return system and want to make sure they are rated for the appropriate pressure.

 

[IDIoit]

the return line caps on our injectors are nothing but a plastic cup, with a compression clamp.

youre thinking too much.

as long as you have the 3/16 matched to the 3/16 and the 1/4" to 1/4" youll be alright

 

[abfiegen]

Well I need to run 3/16" to 1/4" hence the question about fittings. The nipples at the tee fitting (3/16") that runs back to the tank by the firewall don't match the nipples at my new injector caps (1/4"). I realize the means I should have bought the 3/16" return line kit but I tore into the 1/4" kit before I was well enough informed on this subject and wanted to try to make it work. If adding threaded hose barbs into the equation adds problems, which it very well could since it just adds more locations for leaks, I'll just buy a 3/16" kit and do it right the second go around. Chalk this up to a learning experience.

 

[IDIoit]

as the returning fuel also cools the injectors and IP, i would stay with 1/4" altho people run 3/16 without issue.
i had the same issue. i took those brass fittings and cut them off, drilled out and installed 1/4" fittings.
the manifold on the rear of the block that goes back to the tank, i got a brass T and installed 2 1/4" fittings and 1 5/16" fitting to the tank line.

 

[laserjock]

To answer your original question, the return pressure is or should be nil unless you are trying to return a bunch of fuel from a big electric pump.

 

[icanfixall]

On our engines the return line pressure is gravity feed. My guess is less than 1 lb. As for the size issue you are having its simple to remember this. the green clamps will tell you the hose size is 3/16. the red clamps tells you the size is 1/4 inch. Now the actual return line to the tanks found at the firewall is 5/16. So you see that tells you the pressure is nothing at all. I found those plastic fittings in the help section at any auto parts store will handle return line pressures and the diesel does not melt them. Mel from conestoga Diesel Injection shop taught me this and its working fine.

 

[Black dawg]

With the stock lift pump you should around 1 psi revved up.