Time for another monster update as it has been over a month since the last one. What have I done?

Rear axle assembly

Getting this apart proved a ballache. Lots of rusted nuts & bolts – was glad of new impact wrench. Brake lines were the worst. I ended up cutting most of these off. The calipers were pretty shot too. One was maybe rescuable but I decided to get a used pair off eBay and refurb them with kits for new seals and pistons etc. I have all the parts and kit to redo the lines and some new flexis have arrived.

I didn’t completely strip this all down but everything has been cleaned up with a wire wheel and treated to a coat of black paint. It’s not good and I will replace everything at some point. But it’s OK.

Fuel tank

With the rear axle out I could finally remove the fuel tank completely. I ended up having to cut a chunk out of the tank so that I could get to the allen head bolts for the rear axle, so it was completely empty. Took a lot of wiggling and pulling to remove it though. Nothing really salvageable. Fuel pump was a mess.

Rear arches

Part of the reason for wanting to get the fuel tank out was so that I could confidently weld around that area. Driver’s side rear strut top was rusted out at its corner, as is the spring mount on both sides.

Fixing the strut top meant stripping the trim from the rear of the cabin and the boot, and a lot of patient grinding to uncover the true extent of the rust, which just kept growing. I have limited fabrication tools so the repair had to be made up of lots of small pieces of metal welded in progressively. It’s not beautiful but it is structurally sound and that will have to do for now. And no-one is going to notice once it is covered in seam sealer. For now it is covered in a couple of layers of primer while I see to the spring mounts.

In an ideal world I would replace these with some off the shelf repair panels, but I can’t find any. So, I’m making up some over-engineered repair pieces. 3mm steel rings to reinforce the rusted parts and a 1mm folded steel brace on the top. These are largely measured up and templated and when I get time I’ll get them cut out and welded in. Then the back axle can start to go back in, along with the refurbed brakes etc.

Power Steering

I’ve finally welded in the brackets for the Zafira power steering pump. This was delayed by stuck connectors to the ABS pump – I needed to move some of the brake pipes to access the space where I wanted to weld. I managed to get all but one undone without shredding anything with the liberal application of WD-40 over a few days. This created enough space to grind away the paint with my new finger sander and weld in the three brackets.

In retrospect, I wish I had made them from slightly thicker steel (I think it’s 0.75mm), but with the three of them it should be fine. If needs be, I can brace one of them off the heater mounts (below).

I have been hunting around for connectors to replace the stock BMW ones for ages and have even bought a few bits. But I’ve now found an online service who will make up a custom hose with the right fittings for very sensible money, so I’m just going to do that. The old BMW cooling loop was heavily corroded, so I’ll replace this with a little oil cooler on the return line.

Heating

I bought and modified an AC car pre-heater to remove the pump so that it can run on DC. The full 350V of my main pack may be a little much but we shall see. There is now an external 12V DC pump to keep water flowing through it rather faster than I think the internal pump would have managed so that should balance it out.

I fabricated a bracket to hold the heater and pump next to the bulkhead that will be welded to the frame and a former solenoid mount that protrudes from the bulkhead.

I’ll need some sort of filler arrangement. And I need to make up a pipe to take an in-line temperature sensor that I picked up off eBay (irritating 1/8NPT thread that you can’t model in Fusion360). This will connect to an Arduino that will drive a contactor on the live line – a feed from the old A/C connector on the inverter. Plan is to take a simple on/off signal from the wiring from the old solenoid valve that I believe must have routed water from the engine through the heating loop when the heating was turned on in the cabin.

Just waiting on paint to dry on the back of this before it can be welded in, as this won’t be accessible once it is.

Inverter & charger mounts

I’ve cut off my inverter and charger mounts that were welded to the top of the engine mounts. This is because I wasn’t particularly happy with them after lots of modifications, and because I now have lots more space to play with. The charger is a lot smaller than the old high voltage junction box (replaced by the BMW ‘safety box’ now integrated in to the battery box). Plan is to make up some new mounts with fresh steel so that the inverter can be rotated through 90 degrees. This will create more space for the battery box so that getting the lid on and off isn’t a total PITA.

This should also create some more space for the cooling systems, both oil (for the motor) and water (charger and inverter).

Work on the car continues to be held up by various things: building work, earning money, actually seeing my family. And unfortunately, the workshop I hoped I would have by now has fallen through. I’ve been on a big hunt around my local area to find something suitable, but nothing is available at the moment. Still, clear progress being made. Might actually finish it this year…