Generation 6/Replacing Fuel Filter Proceedure
How to replace the fuel filter on the Gen 6 GT4 (ST205)
Before beginning this job ensure you take all the usual precautions when working on the fuel system.
Tools required
- 10mm spanner
- Pliers
- 19mm open end spanner
- 17mm ring or combination spanner
- 14mm flare nut spanner (very important)
- 10mm socket with long extension bar and ratchet
- Cross head and flat head screwdrivers to fit various jubilee clips
- A cloth or rag to absorb spilt petrol
With the car somewhere you can work safely start by removing the negative cable from the battery. Make sure you stick it somewhere that’s out of the way and that it can't make contact with the negative terminal on the battery. This is purely a safety measure to reduce the chance of sparks igniting fuel vapour. The battery cable will be secured with a 10mm fitting. Use the 10mm spanner to undo.
This picture shows the area worked on. The fuel filter is secured to the inner passenger chassis leg and sits under the air cleaner housing. Access is restricted due to space constraints.
1. Use the pliers to undo the hose clamps on the following hoses:
Intercooler to dump valve pipe
Small dump valve to inlet manifold pipe
Oil catch can to main inlet hose. This pipe can be removed completely.
2. Use the appropriate screwdriver to undo the hose clamp holding the main inlet air hose to the air cleaner housing.
3. Pull the inlet air temperature sensor out of the back of the air cleaner housing and tuck out of the way and pull the remaining air hose off the back of the air cleaner housing. This hose is the idle air feed pipe.
4. Undo the 4 clips that secure the upper section of the air cleaner housing and remove the upper section complete with dump valve exposing the air cleaner filter below.
5. Remove the air filter to expose 2 bolts below. Use the 10mm socket to remove these 2 bolts and also the 3rd securing bolt on the outside of the housing to the rear.
6. Unclip the 2 wiring looms and pull the lower air cleaner housing from the car.
You should now be able to clearly see the fuel filter below. This picture shows it.
If you look at the top of the filter you will see a banjo union. This is the output side of the filter. The banjo bolt is 17mm. If you look below this you will see a nut shape formed into the body of the filter. This is 19mm and is used to prevent the filter from twisting as you loosen and tighten the fitting. On the bottom of the filter there is the same 19mm form and a 14mm flare nut fitting.
1. Locate a 19mm open end spanner on the underside of the filter. I found the best orientation ended up with the spanner pointing towards the engine.
2. Use the 14mm flare nut spanner and locate this securely on the lower pipe nut. Remember to undo the filter from above you need to move the flare nut spanner in a clockwise direction.
If you find it difficult to get the fitting undone at first, use a pry bar between the 2 spanners to get the nut initially loosened. Once you get going you should only need to use the flare nut spanner so long as it never tightens up enough to move the filter at the same time. Once you get so far you will be able to undo the nut by finger. Don't remove the nut completely at this stage. Leaving it in will prevent dirt ingress in the next stages. Have a rag handy below the filter to catch any fuel that leaks out.
1. Use the 19mm spanner and the 17mm spanner in the same manor as in the last stage to undo the top fitting. When you remove this fitting recover the 2 washer that fit either side of the banjo union and discard these as you should have a new pair with the new filter.
Ultimately you need to make sure the neither the top or bottom fuel pipes twist during removal. Both of these pipes are expensive and time consuming to replace.
1. Use a small 10mm socket and ratchet to remove the 2 bracket securing bolts.
2. Undo the last bit of the bottom fitting and pull the old filter from the car. Try and get your finger over the bottom hole as quickly as possible to restrict the amount of fuel spilt.
3. Place the new filter over the bottom pipe.
4. Put one of the bracket bolts back in. This will brace the filter aiding refitting of the bottom pipe connection.
5. Using fingers only screw the flare nut back into the filter ensuring that it does not cross thread. It should screw in by hand almost all the way in.
6. Put the remaining bracket bolt back in and fully tighten the two bolts.
7. Fit the top fitting back together remember to put the 2 washers in the correct place.
8. Using the 19mm spanner and the 14mm flare spanner fully tighten the bottom connection. Do not over tighten.
9. Using the 19mm spanner and the 17mm spanner fully tighten the top fitting. Do not over tighten.
This pic shows the new filter in place.
1. Refit the air cleaner housing and put all the pipes back together in the reverse fashion to removal. At this stage don't bolt anything down or do up hose clamps.
2. Reconnect the battery.
3. Switch on the ignition for 10 seconds then switch off again. Repeat this three times.
4. Start and run the engine for 30 seconds then switch off.
5. Check the filter fittings for any leaked fuel. If it’s all dry then completely re-assemble. If there’s leaks remove the pipes and air cleaner housing and fix the leak. Once leak has been fixed re secure all the pipes and air filter housing.
Written by StevenC1603
