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DIAGNOSE YOUR FUEL LEAK!!! READ 4 INFO!!
Ok guys I'm making this thread for everyone who is suffering from the common fuel leak(rainbow colored fluid in eng. valley) that our awesome trucks have. These are VERY common questions on the org. and i thought i could at least help to show how to remove your fuel bowl, where to check for leaks, and some ways to fix your leaks. My truck was leaking from 6 different places, and took AT LEAST one dozen removals of the fuel bowl to finally fix all of my leaks. I'm letting you know now this is a time consuming process. I'm going to show some places of where your truck COULD POSSIBLY, BUT NOT LIMITED TO leak from, I'm an novice mechanic as I'm sure most of you are, and I'm not responsible or liable, for any issues that could occur or continue from reading this thread you accept all responsibilities for wrenching on your own truck, this is just for help or somewhat of a guidance to help spot where your truck could be leaking from since this is a common question almost everybody has asked.
I read this and thought it was good info from JJFlash, he was answering someones question and i edited some parts of it;
The valley can be extremely deceptive for pinpointing exact locations of leaks
I had the exact same situation as yours and turned out to be the big (7/8"...don't remember) bolt that holds the lines onto the back of the pump.
Almost impossible to see and my valley was basically dry too. Other common culprits have already been mentioned.
(i suffered same problem)
Use a good spray cleaner and water, wash your engine and valley as thoroughly as you can, LET IT AIR DRY COMPLETELY, get you a flashlight, fire it up and find a comfy spot to lay on top of your engine and settle in. You might be there a while. If possible, get someone to watch from underneath at the same time. Sometimes it can take an hour for even one drip to form.
Not gonna lie dude, finding fuel leaks on our trucks is a serious PITA.
First tools needed (I am a metric man)
-latex/rubber gloves recommended
-a long flathead screwdriver
-paper towels and rags
ok first, if you still have one remove the PSD cover to give access to the fuel bowl(fb) and fuel pump(fp)
then place a bucket or something to catch the diesel fuel near the pass side front on the engine by the rad/trans cooler lines, because now you have push the yellow tab on the fuel bowl(fb) to "drain" and there should be fuel pouring down the front on the engine through a little hose, it take a min a will drain faster if you loosen the fuel filter cap, be careful as we progress because there still will be a little amount of fuel that leaks out of the fuel bowl still, so make sure your wearing safety glasses/goggles from personal experience
here is my drain hose(IIRC 3/8") that i have extended to keep fuel off my engine when i have to drain my fb, after it has stopped flip the tab back to "close"
now remove the y-pipe (non-ic pictured)
i only loosen the bottom clamps since its easy to slip off on both sides
make sure that you plug the intake plenums and turbo with rags, or paper towels to make sure nothing falls down there, which if something falls down there your S.O.L.
now on the back, bottom of the fuel bowl there are two 13mm bolts that need to removed, i just loosen the bolts and leave them in the holes
now on the front, left of the fuel bowl where the yellow drain switch is at, there is a hose for the drain that needs to be loosened
next unplug the big gray sensor that is around the GPR, and if you can't get to it yet don't worry about it, you can unplug it later.
now move on to the right side of the fuel bowl to the fuel pressure regulator and remove the two 10 mm bolts holding it on
its hard to get a pic of but here it is with the fb removed, there is a bluish colored hose that is attached to the bottom of the fuel pressure regulator and bottom of the fuel bowl, you need to loosen the top clamp that is attached to the fpr
finally make ur way to the back of the fuel bowl and there are 2, (3/8") hoses that are connected to the fuel pump, one on top(finger), one on bottom, loosen these and its ready to remove
also pictured above is the fuel pump, it attaches with two 10mm bolts and i believe makes contact with the camshaft to push the little piston to deliver fuel, there is an o-ring that seals it to the block, but over time, heat cycles, and the destructive properties of diesel fuel, the o-ring erodes, and causes another place for fuel to leak from, it is also is a sign the fp is old and needs replacing, BUT you get new diesel rated o-rings from http://www.dieselorings.com/index.ph...gories&group=5 if your sure the pump is in fine working order, also rubber o-rings will deteriorate much faster, from the diesel fuels physical properties
here is the fb with the fuel filter sensor
here is a pic of the two (3/8") fuel hoses with the fuel filter sensor capped(it was leaking, this is where fuel could be leaking from, on my truck for example)
now SLOWLY begin to tilt the fb back towards the cab, because there are two sensors that need to be unplugged, there is the big gray sensor(mentioned above) and the last sensor is located on the back of the hpop which is in front of the fb
look at the screwdriver tip to see where is located, it is the black plug
another angle kinda hard to see the black female end of the plug
here it is all removed
now that the fuel bowl is removed check to see where fuel might be coming from, keep in mind that some fuel probably spilt on the housing from removal
now spray it down with brake cleaner and give it a good cleaning, this will help find where it is leaking fuel from once its reinstalled, this is a good time to replace the hoses(3/8"), and cap your fuel sensor(1/4" thread ext, 3/8" cap, teflon tape) it that's where its leaking from
after you've done that clean the valley, by soaking up the diesel fuel, and hitting it with some brake cleaner if you want, the most important thing is to just make sure all 3 valleys(under fb, in front of fp, and under banjo thing) are completely dry
here you can also check/R&R any bad fuel hoses(1/4") that run under the dp or turbo
if it is leaking from these hoses, the pass side fuel hose(1/4") on the back of the banjo/wishbone thing which is under the turbo, it is easiest to loosen the dp clamp and shove it out of the way to gain easy access to the hose clamps
also check the wishbone itself, clean the underside of it with a paper towel and see if it leaks, (if you have not found your leak yet or want to see if its leaking from there, i had same issue), since it has two crush washers that are a one time use items they need to be replaced when/if the wishbone is replaced, they are thin aluminum washers that are rubber coated and crusher together once they are installed, its not a big deal just go to ford from them, IIRC they part# PA8375, i'll double check that though
under dp hard to get pic, this is where the pass side fuel return hose is
behind turbo on drivers side valve cover, driver side return hose(1/4"), 15mm bolt to remove, if it is leaking from the drivers side fuel hose on the back of the banjo/wishbone joint, its easiest to loosen the 15mm bolt and remove the fuel hose to replace it, there is a little rubber ring that seals the flared end of the fuel hose to the bolt when you tighten it, this rubber can erode, or break apart and cause a leak
Finally after you checked, re-checked, replaced,...whatever, put it all back together
how i found the easiest way to reinstall it:
1. were to plug the 2( big gray and hpop) sensors back together
2. put the bluish hose on the fpr and tighten
3. put the drain hose back on and tighten,MAKE SURE YOU DON'T OVER-TIGHTEN the drain hose because it is plastic
4. put the 2 (3/8") fuel hoses that run from the fuel bowl(fb) to the fuel pump(fp) back on starting with the bottom hose first, then the top hose, but don't not tighten yet
5. put the fpr back on the fuel bowl and tighten the two 10mm bolts, MAKE SURE TO NOT OVER-TIGHTEN, it is cast aluminum and will crack the housing, or strip the hole VERY EASILY
6. tigheten the two 13mm bolts to the valley, just make sure they are snug and not too tight
7. make sure the clamp are facing up to you to make it easy to tighten with the long screwdriver, and then tighten them down
8. reinstall the y-pipe and your good to go
9. quadruple check everything you've touched, make sure the valley and fuel bowl are still clean, and when your confident, clean up, cycle the key a few times to get fuel in the fuel bowl and crank her up
check for leaks, drive around for about 20 miles and recheck to see if it is leaking, if it is then you can use this method
-this is a little sketchy but i did it plenty of times to get comfortable with it-
if the trucks engine is cool enough, feel under the fuel hoses on the fuel pump, fuel bowl and banjo/wishbone thing, if there is fuel on your hand then that's probably where is leaking from, like a said, its time consuming, and may take a few removals to find it, but if you keep trying you will definitely find it especially with the help on the org., otherwise just tear it down again and repeat the steps and look very hard to see where its leaking from just make sure you don't get additonal fuel on the fuel bowl since it could mislead you as to where its leaking from
I hope this helps any and everybody, especially noobs since this is a VERY common question here I figured i would try to help since i didn't see any type of write up on this common issue, nor did i look very hard though
-Thanks in advanced
Last edited by Gertrude; 04-11-2012 at 01:14 PM.
Last edited by Gertrude; 11-02-2011 at 11:58 AM.
and its best to put a gauge on it to see how high ur fp is, u only want at max 60-65psi
go to the tech files its really easy to perform just loosen the 19mm bolt, inside the hole is a little plunger, pull it out with some needle nose or something, pull the spring off of the plunger put ONE METAL BB from a bb gun into the the plunger where the little spring came from, put it back together
I'm glad I found this so easily. I got my 95 PS in July and the stations around my house all switched to ULS over the last few months. I guess the change finished deteriorating what was already probably something that needed to be replaced anyway. I noticed my fuel mileage got super-sucky over the last week and, yes, I have diesel all over my driveway! Thanks for all this info!