Help, Can't get air out after changing fuel filter

grommet1 · **Posted:** Fri Feb 18, 2011 8:03 pm

Today I replaced the original fuel filter with the new replacement housing + filter, part# 68043089AA. I also purchased the new pig tail to make the new connections. I got everything installed, plugged in, primed and purged. I cranked it up and drove it for 10 miles and it seemed to be ok until I returned home. I tried to crank it again and it would not. I performed another air bleed operation using the hand primer, and I finally got it cranked but it took a while. After it runs and I press the accelerator it starts running rough again. I bled the air again but still get the same thing.
One thing I DID NOT DO is remove the fuel filter that came on the new head assembly when I installed it, but I used the hand primer to prime it with the bleed screw open until I got fuel with no bubbles. I them performed the bleed operation with the bleed screw closed (hand prime until tight, open bleed, close bleed, repeat until no more air is seen). Should I do something else now or continue to bleed,
I leave in the morning for Washing DC!

METCRD · **Posted:** Fri Feb 18, 2011 8:05 pm

I don't mean this to come across as (is your computer plugged into the wall) but have you checked to make sure the fuel filter is tight? And did you prime the rubber seal? When I got my CRD the fuel filter was actually a little loose and allowed it to suck some air.

AZ CRD · **Posted:** Fri Feb 18, 2011 8:09 pm

That sucks . . . literally because of the vacuum feed system. I have no advice for your short term situation. Long term I would consider an in-tank lift pump.

Good luck and I'm sure someone more knowledgeable than I will have some thoughts.

warp2diesel · **Posted:** Fri Feb 18, 2011 8:11 pm

Try loosening up the filter and retightening it, you may get lucky. Enough fuel should leak out to lube up the gasket so it tightens up. Some bone head may have put the filter onto the filter head dry making the gasket not to seal.
Also check your hose clamps and make sure they are snug.
Put in a lift pump and you will say good bye to the headache as long as the connector line between the tank and fuel line is not leaking in any air.

grommet1 · **Posted:** Fri Feb 18, 2011 8:20 pm

warp2diesel:
I think I will try loosening the filter and retightening it. I have read many posts about installing a lift pump, but to be honest I have never experienced any air/vacuum leaks with my housing. Actually this is the first fuel filter change since new, 57,000 miles. Maybe the engine is choking on fuel after having the old one on so long (ha ha)

I actually know better, I just got in a hurry and cut corners...
I am heading out to check the filter housing...Stay Tuned!

grommet1 · **Posted:** Fri Feb 18, 2011 9:28 pm

OK, I removed the entire head assembly, and took the filter off. It was on extremely tight. ANyway it was completely full of fuel, and both gaskets were wet and seated. I tightened the bottom valve on the filter also.
I reinstalled everything, bled it multiple times. Still very hard to crank and now it is smoking badly when it runs. I am at a loss. It is hard to believe that a fuel filter change has radically upset the vehicle like it has. I am almost tempted to put the old unit back on and test, but it is getting late.
Thanks to everyone for the advice, I will attack it again next week when I get back from DC. Looks like we will be taking the Yukon.

Wobbly · **Posted:** Fri Feb 18, 2011 10:10 pm

The hoses are connected as shown here? viewtopic.php?f=98&t=35702&hilit=fuel+filter&start=0

grommet1 · **Posted:** Fri Feb 18, 2011 10:39 pm

The hoses are installed correctly and the clamps are tight.

BlackLibertyCRD · **Posted:** Fri Feb 18, 2011 11:04 pm

I'm not trying to offend you but what was mention was maybe the lines were crossed. The inlet on the outlet and the outlet on the inlet. I don't know if it will bleed that way but it I know I had to make sure I had it right because the lines come up in that same area.

grommet1 · **Posted:** Fri Feb 18, 2011 11:57 pm

BlackLibertyCRD:
No problem, I should have been more specific, but yes the inlet and outlet hoses are installed in the correct position, I am not sure it would even run at all with the hose positions swapped.
It is quite possible that another issue has come up totally unrelated, what are the odds of that?
Other than hard starting and a rough idle, would trapped air cause the engine to smoke very badly like mine is now?

sidebrake · **Posted:** Sat Feb 19, 2011 12:04 am

Run to Home Depot and get some clear plastic tubing in the same diameter as the fuel line (the exact measurement escapes me at the moment). Also grab some clamps and male/male end connectors. Cut the tube in 1 to 2 inch pieces and put it in line with your fuel lines just before and just after the filter assembly.

(1) Observe the clear lines while you bleed the air out. (2) Have a friend crank your engine while you observe the lines. (3) And, finally, observe the lines while the engine is running.

This won't solve your problem, but it will help you figure out where its coming from. If you're seeing air bubbles in the line BEFORE the filter assembly, you've got a leak from that point back to the tank. Check all the lines, fittings, etc. If there's no air before the filter head but there is air after, then it's probably something wrong with the head or filter. If you don't see any air bubbles at all... well... we'll cross that path if/when we get there.

The setup looks something like this:

grommet1 · **Posted:** Sat Feb 19, 2011 12:17 am

Thanks Tom, great advice. I will absolutely try this next week before I do anything else. For now though, I will go to bed and dream about getting a lift pump...

-Billy

mungewell · **Joined:** Tue Jan 11, 2011 6:04 pm **Posts:** 48

I did a filter change a couple of weeks ago and screwed up/missed transfering the little gasket between Water-in-Fuel sensor and the filter. Caused a lot of problems with air... sounds like you are more competent than me, but it doesn't hurt mentioning it.

Simon

Help, Can't get air out after changing fuel filter

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