Replacing the Fuel Filler-Pipe

There was always a strong smell of petrol at the back of the car, which I put down to the exhaust system, and the petrol gauge worked very poorly, barely moving upwards with £20 in the tank. After a couple of weeks I noticed a giant pool of petrol under the car while filling up and was relieved to find it was only leaking from the feed pipe to the tank while filling up and not the tank itself. It figures, seeing as the bare steel pipe itself passes straight through the open rear wheel-arch!

I got a quote of around £200! from my nearest Scoob service-centre to fit a new pipe so I turned to the forums and found many people quoting similar figures of £180 and £190 even without fitting! eBay was a different story, with used filler-pipes going for as little as £30 in poor condition to £60+ for one as-new. I went for the latter, with a mint example off a Jap WRX @ £58 delivered. The import part differs only from my UK original in having no nozzle adaptor for our fuel-station pumps or inner-flap - it's just an open pipe to the tank.

I wonder how long before the new pipe goes like the original, which was in a sorry state as you can see below. As well as the U-bend leaking petrol, the nozzle had rotted away so much that daylight could be seen through it looking up through the wheel-arch. I take it the problem had been around for some time too - over the years it's been fixed with a welded metal plate, metal body-filler, a rubber-tourniquet, about six different types of tape and pasted in red Hammerite - all without fixing the leak!

The fitting was really not a difficult job, provided you have basic home-garage tools. Apart from a few time consuming snags we were able to get the new pipe on in about 2 hours, making it well worth the money saving!

I couldn't find a how-to-guide for this job online, so I have written this one for Scoobynet:

* The filler-pipe and fitting procedure are exactly the same for ALL models of classic Impreza from 1993-2000. *

REMOVAL:

1. Lift the car and remove the driver's-side rear wheel. [I used a trolley jack and put an axle stand under the trailing arm.] You can see the filler-pipe exposed in the wheel-arch where it passes through the body and snakes down to the fuel tank.

2. Remove the plastic protector from around the filler-pipe by first removing the one or two screws holding it in place using a 10mm wrench. [Subaru provide suitable spanners with the car's toolkit, but some of the screws and clips are quite hard to get to without a socket-set with some reach.]

3. Open the fuel-flap and remove the fuel filler-cap. Remove the three 4mm crosshead screws holding the nozzle of the filler-pipe in place, shown below. [Mine we're seized on so tight that I eventually stripped the screw-heads and had to drill them out. These little screws are made of some remarkably hard steel and I ruined several HSS drill-bits while barely cutting the screws. In the end I bought a HSS-CO bit for £8.99 from my local B&Q, which did the job with plenty of oil - so make sure these screws can be removed before disconnecting anything else!]

4. Squeeze open the finger clip at the top of the vent pipe and slide it down out of the way. Slide and twist the rubber vent hose down off the filler-pipe vent. [Or if it is too badly corroded as mine was, it may be necessary to remove the rubber-pipe from the vent-pipe on the chassis first and retrieve the rubber-hose once the filler-pipe has been removed.]

5. Underneath the car, just as the filler-pipe passes under the rigid cross-member, you should see the start of the rubber-hose connecting it to the fuel tank and the jubilee-clip. Loosen the jubilee-clip using a 10mm wrench and slide it down onto the filler-pipe. Press the edges of the rubber-hose to loosen its seal before the filler-pipe is unfixed. [It is difficult to loosen the jubilee-clip without a socket-set with about 10cm reach. The jubilee-clip is also hard to keep in place when it starts to open, but its awkward to get two hands into the gap and you may need someone else to reach in through the wheel-arch to grip it.]

6. Remove the one or two screws that hold the filler-pipe onto the chassis using a 10mm wrench. The filler-pipe should now be free to move around and held in place only by the rubber-hose joining it to the fuel tank. [Mine only had one screw and the head sheered off so was forced to drill out a new hole in the bracket and insert a 4mm nut and bolt.]

7. Slide the filler-pipe out of the rubber-hose now that the pipe is free to rotate. The pipe’s U-bend retains a cupful of petrol so hold a container below the lower spout to tip the contents into. Lower the filler-pipe until the nozzle is free from the chassis and the filler-pipe can be removed through the wheel-arch.

REFITTING:

Reverse the removal procedure to fit the new filler-pipe.

It is unnecessary to replace the black plastic that surrounds the nozzle of the filler-pipe, although most second-hand pipes I've seen come with one. It contains the opening mechanism for the fuel-flap and a drain-pipe that are both inside the bodywork and very tough to get to so it’s not worth bothering, although it might be worth replacing the steel mounting-plate within the plastic-surround if you get a new one with the pipe.

The new pipe was bare metal, probably good for the remaining life of the car, but I sprayed it with a quick coat of zinc-primer anyway before fitting and rubbed some copper-grease over the main rot point on the base of the U-bend.

I also replaced the three 4mm screws I drilled out from the filler-pipe nozzle with some much milder steel ones, bought for 50p from a small hardware store.