Fuel filter replacement

[dieselrealtor]

I am planning to replace my fuel filter this week & have searched the prior threads, cannot find the procedure for replacement & proper bleeding.

I am also thinking of adding a pre-lift pump filter, any suggestions, where to buy, etc?

Thanks for the help.

[dslpwr]

1 remove fuel tank fill cap

2-open air bleed valve on top of filter

3-remove element nut on top of filter

4-lift element straight up

5-install new filter by aligning to matching slot

6- replace nut

7- open air bleed valve. On my 95 i can put transmission in drive and turn key to start which will make lift pump run and remove air from filter. Or yoy can remove F/sol fuse and crank engine to remove air.

8- close valve and install filler cap back on

[dieselrealtor]

Thanks a bunch, where in OK are you?

[MTTwister]

4a - Check for the little screen in the bottom of the old filter - evidently it can come out and get tossed. Of course, I've never checked mine - hopefully it's still in there..

on '97 - pump should prime during Glow cycle.

[Hubert]

As always try and follow good shop practices etc. I like to suck out all of the diesel in the filter bowl before istalling the new filter look for chunks of what ever. If you don't the new filter will also get crappy unfiltered diesel on the inside of the filter! I use a a turkey baster then a clean rag to wipe down the bowl and blow out any crap with airhose. I kinda swaddle the rear of the engine with rags to minimize the mess.

You can fuel sample before changing filter too for a look see at fuel quality and as a check of the lift pump.

Its not bad and you should change as often as you can comfortably.

[jjbouwens]

talking about the little yellow cylindrical screen in the bottom of the filter. This screen is not symmetric.One side has a circular cross section (I think you call that a torus like the inner tube of a tire)the other side has a slotted design like the top of a medieval tower of a castle. I always though that this slotted design should be at the bottom and the torus at the top. At least that is the way I pushed the yellow screen over the center pipe. Any opinion?

1996/P30/RV/K&N air filter/gauges inlet pressure-post turbo temp/racor fuel filter upstream of lift pump/70t Km.

[slagona]

2-open air bleed valve on top of filter
3-remove element nut on top of filter
I'd add:

2A - attach clean hose to air bleed
2B - open "water in fuel" filter drain valve (brass T valve attached near Thermostat)
2C - blow into clean hose to drain fuel filter canister
2D - close "water in fuel" drain valve

This ensures that unfiltered fuel does not find it's way into the "filtered" side of the system when removing the old filter. Extending (replacing with longer hose) the water in fuel hose so that it is easier to catch the fuel spewing out is also a good thing. As stated above, clean out the bottom of the bowl after removing the filter.

Another way of filling the filter bowl is to remove the lift pump's relay and insert a jumper to energize the pump. Going from memory, jump the upper right hole (where the relay's pin would be) to the lower left hole. But my memory ain't so good.......

[DennisG01]

All right, now you guys have me thinking. Do ALL filter canisters use that little filter screen? I can't remember seeing one, but I never specifically looked for one, either.

[MTTwister]

I've only read that they can -sometimes- come out with the filter. I've never checked mine of course, so if it's gone, it's gone. Next time, tho' I'll look for it.

[Dimsdale]

My method is slightly modified from the above:

(I do this with the engine warm to dispense with the glow plug cycles when cranking the engine. I also clean the area as best as possible to keep any dirt out of the filter during changing)

1a: Pull filter drain hose up from where it runs alongside the engine and put in a glass bottle (Corona beer bottles are pretty good for this job. Also has the advantage of having to empty same prior to the job!) Run the engine and open the brass "T" to purge any water and crud from the bottom of the filter. This way, I can check to see if the lift pump is working, and if there is any water or other contamination in the tank.

Close drain valve, turn off engine.

Attach clear tubing to the air bleed valve (available in hardware stores), reopen
fuel drain valve, and blow out most of the residual fuel in the filter housing. Leave clear tubing attached.

7a: Turn on ignition with gear selector in drive to prevent the starter motor from cranking, and let lift pump run for the few seconds it runs prior to ignition (this is on a 99, BTW). Keep cycling the lift pump until clear, bubble free fuel comes out of the air bleed valve and into the clear tubing. About two - three cycles do it for me. You can see it through the gap between the raised hood and cowl if you are doing it yourself.

Close air bleed valve, remove tubing and bottle, put trans selector into park and start engine. Replace fuel cap after starting. Check for leaks.

Pour the excess fuel in the bottle into the home heating oil tank if applicable! (Hey! That stuff is expensive!!)

If there is a post filter change cleanup to be done, some Simple Green really works well and smells pretty good too!

[dieselrealtor]

Got it in a little earlier.

There was no screen.

Very little crud in the bottom of the bowl.

Got another question, when I got the bleeder valve open enough for stuff to come out, very little came out of the tube, most of it came around the valve & all over the floor.

Is it possible that I have a weak lift pump?

[Hubert]

Do you mean a lot of diesel came out the air bleed (plastic knob on top of filter) and not the waterdrain (brass valve near the alternator) ? If both were open thats ok flow will take path of least resistance. But if you are just sampling the waterdrain you should have a decent flow idling. Search other posts but it should fill up a pint in so many seconds.

The lift pump is not real strong approximately 3-4 psi or there about a little more or less depending on things. Depending on load the IP can use all of what Lift pump supplies. You could have a weak pump but its probably normal. Thats just one more arguement to keep a clean fuel filter.

[dieselrealtor]

Yes, I had the waterdrain closed & was bleeding the air after the new filter was in.

[tom.mcinerney]

jjbouwens -
The fuel conditioner assy features two coaxial stainless thinwall tubes. The nylon filter cylinder segment has different diameters at each end. My interpretation was that the large end goes down to rest on the lip(top edge) of the larger diameter shorter tube. The smaller diameter end of the screen goes UP, so it seal on the outer edge of the thinner , taller tube.
Realtor-
Any prefilter is better than none. Nice ones have transparent bowl, water drain, water sensor, maybe heater. Search for fuel filter post by tbogemirep....or jbplock

[jspringator]

My screen was intact when I bought the truck at 120,000 miles (a miracle), but I lost it during a filter change. Since I have a pre-filter, I am not going to worry about it.

[Hubert]

Diesel Realtor,

So you mean you put a hose over the little knipple on the air bleed knob/valve. Yes that leaks like a sieve under the plastic knob with LP on. It is good for blowing air in cannister like above posts and draining diesel out the water drain. I did try that and it worked pretty well to lower it above the outgoing tube but you still have to get some diesel out of the bowl and wipe it clean. And why I pile a few rags around back of engine changing filter. IMHO just use air purge valve for purging the air.

[JohnC]

If you open the bleeder a little it'll bleed out the top of the knob. Open it a little more and it just flows out from under the knob. Not a real clever design...

[DmaxMaverick]

Originally posted by JohnC:
If you open the bleeder a little it'll bleed out the top of the knob. Open it a little more and it just flows out from under the knob. Not a real clever design... My sentiments, exactly! The Stanadyne 80's were the same way. Why install a tube, and O-ring seal, just to have more fuel pour out under the valve, than the tube? The water drains on the Racor/Duramax filters are the same way. They have a hose nipple on them (GM didn't bother including a hose), but even if you use a hose, the fuel still pours out the threads. The air bleed is just a threaded plug, with an O-ring seal. Open it, and fuel just pours out all over the top of the filter head, and onto everything below it. Poor design is an understatement. How difficult could it be to design it properly? The 6.5's water drain is the best setup I've ever seen, believe it or not.

[dieselrealtor]

Thanks to all for the replies, sounds like it wasn't just me.

Call me a little backwards, but I expected it to work like a brake bleeder valve & most of the fluid & air to come out of the hole, not around the threads.

[dieselrealtor]

got a little button happy there.

All is good, new fuel filter, trans filter, more fluids to do before the end of the week.

[trbankii]

Just had things apart this afternoon to replace the filter. Did not see any screen in there as was mentioned a couple times here (truck is new to me at 130K+ miles). What do I ask for or order to get a new one?

Also, had a devil of a time with the whole thing about putting the tube on the bleeder valve and purging the air through it. Like others, just managed to get diesel all over the top of the filter. How do you judge how long to pump when you cannot get any fuel through the tube to see if you're getting bubbles or not?

[tom.mcinerney]

I don't know if any GM dealers stock the screen, some only stock new replacement conditioner assys. I phoned the friendly folks at Gomers/US Diesel, who sent me a new screen weeks before the LI,NY Stanadyne regional operation got any [i think they wanted to sell me a new complete assy]. If you look down on the tubes you don't see much. Always look into the bore of removed filters for the screen.

[trbankii]

Thanks for the reply. I'll look down the tubes again. But I have a feeling that the screen is long gone from the original owner...

[tom.mcinerney]

Very possible. I removed one last week and found the screen within ; removed with index finger and reinstalled in filter house.

It is obvious when there isn't a screen--
One either sees:
1.) a thinwall tube with a tan/yellow recessed border OR
2.) a thinwall tube with a second , slightly larger diameter thinwall tube encircling the first , down at a lower level. So if you can see the gap between the tubes, you're missing the screen.

If the screen is present it should be down flush against the top of the lower (larger) tube. Sometimes they rise/slide up when the filter element is withdrawn.