DieselTalk

DieselEngineTrader's FREE Diesel Engine Forums

new topic search Categories login View Ford Diesel Engines

CATEGORY LISTINGS > FORD DIESEL > 7.3 FUEL DRAINS BACK

[ REFRESH ]

Thread Title:

7.3 FUEL DRAINS BACK

Created On Monday March 29, 2010 08:24

66F250

Posts: 2
Joined: Mar 2010

Monday March 29, 2010 08:24
Hi All Why does the fuel drain back out of the fuel filter? I have an '89 E350 & my buddy has an '86 F250 & they both are 7.3 & do the same. They set a couple days & you must bleed the air from the filter to get fuel so they start. Is there a check valve or what? My E350 is under 100,000 miles. Thanks in advance. JIM ------------------------- GIT-R-DUN

Quote

Top

Bottom

truckdoctor

Posts: 33
Joined: Jun 2012

Tuesday August 21, 2012 22:03
Sometimes the lift pump will cause this or you could have a tiny hole in the fuel line between tank and lift pump.

Quote

Top

Bottom

dsldr

Posts: 30
Joined: Jan 2010

Saturday January 18, 2014 17:59

Take the little line from the filter head to the return loop on the injectors, and plug it on both ends with a steel ball, then put it back on. This will reduce the likelihood of air seeping in, especially if the injectors are weeping fuel around the plastic return fittings at the top of each injector. But it will also make it a bit harder to bleed air out if it is run out of fuel. Water separator on firewall leaks air, if you have one. Lift pump will leak air. Lines to tank will leak air. And the fuel tank selector valve will leak air. Also the low pressure lines under the hood from the lift pump to the filter head, the filter head to the injection pump, all use rubber seals inside the fittings. If these deteriorate, they will suck air too. You ot a lot of work ahead of you... if it was easy, everyone would do it.

Sometimes I have had to mount a 2 gallon can under the hood, prime the system with this, and run it for a half hour, shut it off, and see if it would start the next day to prove out leaks under the hood. Once that is tight, start going along the chassis replacing lines. GOOD LUCK.

-------------------------
gregory l ralyea