ST3 Maintenance - Fuel Filter Change

[ducsbill]

I'm working my way through the maintenance items on my 2005 ST3. Just thought I would offer a few tips for those getting ready to change the fuel filter. These tips assume that you are at the point that the tank can be tipped up

1. Get as much fuel as possible out of the tank. There is a drain plug on the bottom left rear corner that you can use or you can use a siphon gadget. If you use a siphon, be careful about putting anything hard down in the tank.
2. Be careful when removing the flexible fuel lines attached to the hard brass lines coming out of the tank. Don't just yank...you need to gently finesse these off. They are a tight fit. I found I could get a better handle on them to twist if I held the tank more upright with my left hand while twisting with the right.
3. You may have one or two other lines coming off the bottom of the tank besides the electrical connection. If you're unsure, mark them somehow so you can put them back.
4. The electrical connection is a tight fit. Be sure to hold the connectors, not the wires.
5. After you have the tank off, you'll be working with it upside down, so be sure you put a couple of layers of towels on your work bench.
6. You'll need three 6mm bolts to pop the assembly loose from the bottom of the tank. These screw down into the holes provided after taking off the three hold down nuts. Screw them in gradually, going around from one to the other. Don't try to pry the assembly out. When lifting the assembly up, be careful about the O-ring. If you damage it, you'll have to replace. It is possible to reuse them a time or two.
7. After the assembly is loose, there are two internal fuel lines and an electrical connection that need to be unhooked. You can only pull up about two inches. The two fuel lines (these are the overflow lines) use hose clamps and the screws can be seen by looking from the front end of the tank.
8. Before removing the filter itself from the assembly, make sure you have several shop towels handy. You'll have about a quarter cup of fuel come out of the filter when you undo the inlet side.
9. I undid the outlet line clamp on the filter before loosening the screw on the plastic filter holder. Make sure you keep track of which way the arrow pointed on the old filter.
10. Before reassembly, inspect the O-ring. It shouldn't have any nicks and should fit into its groove snugly. If it's loose or floppy, you may want to replace it. Reinsert the assembly gently back into the tank. Pay attention to the "Front" mark.
11. After you have reattached the electrical connection and the two fuel lines, place the assembly into place and work your way around the assembly, gently working it down into place. It is a tight fit. Eventually it will "pop" into place.
12. Before you put the hold down nuts in place and tighten them to spec, make sure you have several shop towels handy. As you tighten the hold down nuts, the tank will be pressurized just slightly and you may have fuel start to weep (or worse) out one of the overflow holes on the assembly. Work relatively quickly and stand to the side when you bring the tank upright. Have a couple of towels in hand to catch the fuel coming out of the overflow.
13. Set the tank upright someplace where you can check for leaks around the assembly. If you see leakage, the O-ring probably isn't sealing correctly, so you'll need to remove the assembly just enough to ensure the O-ring is is place. Check for leaks again...if necessary you may have to replace the O-ring.

Hope these tips are of use.
Bill 'ducsbill' W.

[YveST3]

Originally Posted by ducsbill

12. Before you put the hold down nuts in place and tighten them to spec, make sure you have several shop towels handy. As you tighten the hold down nuts, the tank will be pressurized just slightly and you may have fuel start to weep (or worse) out one of the overflow holes on the assembly. Work relatively quickly and stand to the side when you bring the tank upright. Have a couple of towels in hand to catch the fuel coming out of the overflow.

Hope these tips are of use.
Bill 'ducsbill' W.

Thanks for those usefull tips Bill

But beware that you haven't nothing with a open flame like a gazoline radiator or something because a french ST lister did also his fuelfilter change and this happend to him ;-((

[dharhay]

I can add that most everyone replaces the o-ring everytime you are working on the fuel pump assembly. There are alternatives to the high cost of the stock o-ring that work just as good

[YveST3]

Originally Posted by dharhay

I can add that most everyone replaces the o-ring everytime you are working on the fuel pump assembly. There are alternatives to the high cost of the stock o-ring that work just as good

Let it dry and it takes his original form.

If you are hurry it's good to have one spare so you can change it without loosing time and you have one already for the next time.

[Gearbox]

One additional point.
When assembling make sure the housing and seal are totally dry.
Then put a slip of petroleum Jelly (Vaseline) around the surface of the hole in the tank which helps it slide in nice and easy.
Dont put the jelly on the seal/unit because it causes the seal to rise up on the housing instead of sliding into the hole !
I know because I ruined 2 seals before got it right.
(Definitely worth having a spare to hand)

[redfourme]

Ducsbill,

I like your posting layout! 1., 2., 3., ummm, oh yeah, 4., 5., etc.

It's a format I can follow! Keep it up! I'm coming up on 12k maint and your posts will be added as source info. Thanks.

Has anyone moved the fuel filter outside the tank? Also, what type of replacement fuel line are folks using? Just wondering.... LT mentions using regular high pressure line and replacing it when the filter is changed. This way the lines don't get that old, so I see the argument for leaving the filter in the tank.