Hangar works #19 – Repair of the fuel filter support

Last weekend I spent many hours in the garage soundproofing and sealing the 3-Wheeler’s cockpit (see Hangar works #18).

To do this, I had to dismantle some parts of the car, such as the seats, the backrest and the seat bulkhead panel. To remove the backrest, I had first to remove the boot tray, exposing the whole rear wheel area.

Taking advantage of the fact that I had access to that area, I cleaned as much as I could and checked that everything was in its place, and the screws, nuts and all the parts susceptible to loosening were well tightened.

And then I had a bad surprise: my fuel filter was hanging from its bracket, but totally loose. The support seemed to be broken.

Being very concerned about having a piece of the pressurized fuel system loose, I immediately checked if this was normal, chatting with my colleagues and discussing in the Talk Morgan forum later.

I received pictures and found some drawings, showing different supports and brackets. The supports holding the fuel filter have evolved with the years, so not all are the same. My car being one of the latest manufactured (December 2019), it has a new support consisting of two pieces welded together. The first piece is an Ω-shaped bracket that is screwed to the chassis structure, behind the backrest. Welded to it is the second piece, consisting of a simple O-shaped metal plate, so like a ring, with an open side with a screw, that embraces the fuel filter. The fuel filter is secured to it by tightening the screw.

Investigating further, and analyzing the pictures received, I suspected that my support was mounted already broken, because some drawings and pictures showed the two pieces welded back-to-back, and not by the internal faces of both pieces. Like shown in this drawing.

Just removing the boot tray, there is plenty of room to access the screws and bolts. All screws are M6, so using a 10 mm wrench you’re good for all screws, bolts and nuts holding the Ω-shaped bracket and the filter itself. Once all are loose and removed, I can slide the support out from the filter.

The first thing I notice is that I was right about the two pieces being welded together, but also wrong about how they were welded. They were not welded back to back, but by their internal faces.

My initial anger has turned into simple frustration when seeing that the piece has been split by its weld. At least I can say that the design is good at welding both parts by their internal faces, since when what happened to me happens – that the welding fails – the part that holds the filter remains hanging from Ω-shaped bracket, instead of falling on the drive belt next to the left shock absorber, which would have been disastrous.

Here below you have some detailed pictures my broken support. It’s a pity to see such a piece broken with just 4500 km.

If you look closely, you will see that the two pieces were welded together by just a couple of small solder spots. The vibrations of the car have broken these two small weld points, even though the bracket only holds the fuel filter, which is light, and without tension of any kind.

The good news are that this is easy to fix. A couple of drills and good quality marine degree stainless steel bolts, lock nuts and washers, and the support is back with, in my honest opinion, a more solid and much more reliable union of its two pieces. I chose to do this task using two M6 bolts and lock nuts, to be aligned with the size of the original ones used in the support. One set of bolt and nut may suffice but putting two will keep the assembly more solid so I can really forget about it.

First thing to do: drilling the two holes in the O-shaped ring that embraces the fuel filter. Once fixed to the vice, I start drilling with a small diameter drill, and increase to end up with the correct size, as usual. I better change the size of the drill as many times as necessary rather than trying to drill directly with the “big” bit and do a mess. And with this support, this is really the best way, because the support, that seems to be made of dichromate steel, is soft as cheese. Using the high-quality bits, I don’t have to do any pressure for drilling. Just with the weight of the drill, and the machine at the lowest rpm, the bit cuts through the support like a hot knife through butter.

In this case the sequence goes as follows: 2,5 mm bit, then 4 mm, and finally the 6 mm one. This is an easy and fast task.

Once the holes are done on the O-shaped metal ring, it’s time to use this piece to mark the holes to be done on the Ω-shaped bracket and repeat the drilling process.

With all drills finished, and the edges of the holes smoothed with a metal file, I check that the chosen bolts and nuts fit correctly. The M6 bolts, lock nuts and washers are made of 316 stainless steel. The bolts have a hexagonal head and are 16 mm long. I use a tooth washer for the side of the bolt’s head and standard washer with a nylon lock nut on the other side.

I tight them with a 10 mm combination wrench (box-ended side) and a 10 mm socket wrench.

All fit in and get very tight thanks to the lock nut on one side and the tooth washer on the other side. But the 16 mm long bolts are a little too long: they protrude from the side of the Ω-shaped bracket. The ideal would have been to find 13 or 12 mm bolts, but 16 mm was the shortest I found in the hardware store.

To solve this little problem of excessive length, I use my good friend the Dremel tool to cut out the excess length of the bolts.

Being careful not to damage the support, it takes me around ten minutes to cut properly the two bolts and smooth the cut surface.

Now the bolts don’t protrude over the Ω-shaped bracket, so they won’t interfere with the chassis plate where this bracket is screwed to.

The result is neat. And, in my honest opinion, a lot more solid than the support as it comes from factory.

Down in the garage, it takes me less than 10 minutes to fit the support and fuel filter back in place. I did not need to disconnect the fuel filter. It’s really easy and with a simple 10 mm open-ended wrench you have room to tight all the nuts.

You just have to be careful to put the fuel filter in the correct position, as it has a short pipe section ending with a yellow cap that, if the filter is not twisted to the best position, can touch the spring of the left shock absorber. In the picture below you can sense (because the photo perspective doesn’t allow you to see exactly how close it is) how close this pipe ends by the spring. It’s just 3 cm away! If the filter is twisted counterclockwise, this yellow cap will be in direct contact with the spring.

After closing the boot tray and put away all the tools, I go for a short drive to make sure everything works fine. The 3-Wheeler roars as it should.

There is no reason to think that all the new fuel filter supports fitted in the latest 3-Wheelers will fail as mine. And as commented before, if they fail, the design is good, so the fuel filter doesn’t fall over the drive belt. However, if you are a more preventive than reactive owner, I recommend that you take the time of reinforcing the support with at least a drill with a screw and nut, in case the welding fails like mine.