i have heard there is extremely high fule system pressure how would you release it to replace say an injector line or injector cant find the instructions on the web anywhere
1988 f-350 7.3l

 

With engine off just crack open an injector pipe nut and a little fuel will dribble out.

 

Unless running there is very little fuel actually under high pressure (only what remains in the Injector lines) ...

Nothing to worry about.

-Enjoy
fh : )_~

 

What Festus said, if you're messing with anything but the lines between the IP and the injectors you're good to go as is, this ain't no fuel-injected gasser with the 40+ psi everywhere. And if you're removing the injector lines as Lazy K said the moment you crack a line nut open whatever residual pressure there maybe will be released right away, no flooding with fuel either... These fuel systems are a piece of cake to work on, for the most part.

 

do you have to restore the pressure somehow?

 

No, It will self bleed as soon as you try to start it if the system is working properly.

-Enjoy
fh : )_~

 

It greatly helps if you fill up the filter with fuel before you screw it on tho.

 

somehow.
crank and crank and crank lol.
that's why they always say to never run a diesel out of fuel.
remember when your ready to start it back up (prime it,using your starter) to crank for a max of 20 seconds and then stop and wait for the stater to cool down for at least 2 minutes before cranking for another 20 seconds.
repeat as needed.crack open an injector line or two to help bleed air if needed,and have a battery charger handy.preferably another running vehicle and jumper cables for max cranking amps.
once it fires,shut it down quickly if you did open an injector line or two,or three lol,then tighten them,then start it.
plug the pig in too.the warmer the better.like stated,have the fuel filter full first.
(advance search: " electric fuel pump " /pre-powerstroke section, to see if the idea is of any interest to you.in which case the instructions would read as: "after fuel service repairs.spin on empty fuel filter to avoid the mess,sit in the comfort of the cab,turn the key forward,and wait for 30 seconds.start vehicle as you normally would and drive away." )

 

Yes, Pre filling the Fuel filter is wise, A good time to fill it with your favorite IP lubricant!

Cracking an Injector will not help bleed the system, the return system is what bleeds the system, the high pressure side needs no bleeding ... Once the IP has fuel 1 or 2 injection cycles per cylinder will have the injector lines and injectors free of air ... Not hardly worth cracking injector lines loose for!

If you know the history of the Diesel, you will know that until the advent of the return system they were not acceptable for general public use because of the issues of running out of fuel then having to do crazy complicated bleeding procedures to get fuel. In those days you had to purge all air through the injection pump and out the injectors, that was a nightmare, techs learned tricks to assist, but not things the general public were capable of doing.

The advent of the return system changed that, no longer was a complicated procedure required to get the Diesel running after running out of fuel!
Add fuel and crank (following recommended cranking/cooling time) till she starts, usually within one or two cranking cycles!

If you fill the filter, they usually will start within the first cranking cycle unless things are completely wore out ...

-Enjoy
fh : )_~

 

To add to what Festus said, my factory lift pump would fill up the heat exchanger at the bottom of the radiator (normally used as a trans cooler on trucks with slushboxes) and two fuel filters in two 15-second cranks, third time I hit the start button she'd fire right up.

 

You run your fuel through the trans cooler in the bottom of the radiator ... Interesting!

To bad the previous owners butcher filled the cooler ports and petcock full of lead, along with the 5lbs rattling about inside on my 86. I'm not joking, When I pulled the bottom hose off to drain it something kept plopping into the bucket, I found out what it was afterwards when pouring into containers, then I shook a bunch more out after it was removed!

Gawd, I hate peeps that do work like that!

-Enjoy
fh : )_~

 

Yes, I used the trans cooler as a fuel heater last winter, and my E4OD was purely air-cooled. Then I read on here that hot fuel is bad for your IP, so I switched back to how things were initially - fuel directly to the lift pump and into the IP (still two filters tho), and ATF through the factory trans cooler and into the A/C condenser and then back to the transmission.