Cadillac Tech Tips - How to fix it Discussion, Fuel Filter Replacement for an '02 SLS in Item Specific Cadillac Discussion; Gentlemen,
Just finished replacing the fuel filter on my '02 SLS and wanted to pass on a couple of Tech ...
Just finished replacing the fuel filter on my '02 SLS and wanted to pass on a couple of Tech Tips for anyone getting ready to replace an old and neglected fuel filter. Remember ALL of your Safety Precautions on this Forum.
1. IF you read the Cadillac Service Tips on the Tech Archive Page you will read that replacing the fuel filter involves nothing more than '...breaking the plastic clip with a screwdriver and removing the old filter.' Unfortunately for some of us with OLD fuel filters in newer Northstars life just ain't that easy. An '02 with 104K miles and 4 winters in the NE constitutes old and rusted in my book. IF I didn't know better I'd say I just replaced the original fuel filter.
NOTE: I did NOT follow the recommended procedure for pulling the fuel pump relay and running the car until it stalled. I have a gut feeling that particular procedure is for the mechanical fuel pump engines. There is a Schraeder Valve under the engine plastic cover cowl. The valve is covered with a black plastic cap and is located next to the #1 and #3 cylinders on the FUEL Rail. With engine OFF, key removed, remove cowl, remove valve cap, depress valve stem (just like letting air out of a bike tire), and you will see a few drops of fuel trickle out because the system is NOT under pressure with the engine and key OFF.
SINCE the newer N*s should NOT be pressurized with the engine and key off this was a SAFETY check for my own benefit. Replace Cap, Replace Cowl (2-13mm black caps), secure your tools and rags, and close hood.
2. The AFT portion of the filter required needle nose pliers and a firm squeeze on the clear snap clip to unleash the fitting. The BLACK portion of the fuel supply line does NOT get squeezed...only the clear male clamp. Look at your NEW filter's clamp and you'll see it. You will get a trickle of fuel from the aft end of the filter and supply line coming from the tank. I used an old coffe can for capture.
3. The hard part...The forward part of the fuel filter has a typical male nut compression fitting (pretty sure it is a 16mm but since I only had a 15 and a 17mm open end wrench I used my Crescent Wrench) that screws into the female nut end of the front part of the fuel filter. I used my 13/16" open end wrench to HOLD the female nut and my Crescent wrench to unscrew the compression fitting nut.
NOTE: My hardware was so old and rusted that I had to spray WD40 on it 3 times and it still wouldn't budge. I sprayed it a fourth time and went to bed. 8 hours later I got up, sprayed it again, and it finally broke free. Do NOT force the nut off. You will end up twisting the aluminum supply line and that means a whole new thread on repair procedures.
4. You will get a trickle of fuel from the filter and the supply line going to the fuel manifold. Once again...the coffee can for capture.
5. When installing the NEW filter I put a dab of anti-seize compound on the hardware threads, both male and female, and reversed the above procedure. However, you do NOT need the needle nose pliers to install the rear portion of the filter. Just line up the tabs with the black clip's open slots and push in the aft end of the filter. You'll hear it click in place.
6. Installation was very smooth and hassle free. The OEM Replacement Fuel Filter is actually very simple to replace IF you don't have the neglect I obviously had from the 1st owner. The Cadillac Historical Service printout actually showed the fuel filter on this car being replaced twice before I bought it...hard to believe once I got this one off and split open...very rusty, neglected, and nasty.
NOTE: Prior to starting your N* (only N*s with the electric fuel pump located in the fuel tank) Place your KEY in the ON position and wait at least 15 seconds. The electric fuel pump is pressurizing the system now (30-40psi) so go ahead and start the engine. Mine immediately started. With engine running check underneath the new fuel filter for any leaks or seeps. I had none and neither should you. Document your service and move on...
Automobile(s): 2006 STS 1SF V8 - pearl white with tan interior
Re: Fuel Filter Replacement for an '02 SLS
Just wanted to say I just changed the filter in my 1998 STS, and these directions were great! Just like having my friend that actually knows what he is doing right there ridiculing me every step of the way, but without the ridicule!
Thanks again, on behalf of all of those that have used these directions thus far!
Automobile(s): White Diamond '03 DHS (with DTS floor shift)
Re: Fuel Filter Replacement for an '02 SLS
"NOTE: I did NOT follow the recommended procedure for pulling the fuel pump relay and running the car until it stalled. I have a gut feeling that particular procedure is for the mechanical fuel pump engines. There is a Schraeder Valve under the engine plastic cover cowl. The valve is covered with a black plastic cap and is located next to the #1 and #3 cylinders on the FUEL Rail. With engine OFF, key removed, remove cowl, remove valve cap, depress valve stem (just like letting air out of a bike tire), and you will see a few drops of fuel trickle out because the system is NOT under pressure with the engine and key OFF."
Actually that proceedure IS for an electrical pump and is technically the safest way to depressurize the system since no fuel is present externally. You simply burn it til the engine uses it all. Personqally I use your method, but in theory the system should hold pressure when shut down so there may be 45 psi of fuel pressure behind that schreader valve, and you may get an oz. or so out of it. Be carefull. Put a rag over the schreader to catch and absorb any gas if you don't have a pressure guage with a bleed valve on it and do it on a cold engine.