Today was a very good day, I completed several jobs that have been hanging around for a while. I didn’t get every thing done that I had planned, but then I never do…. still it was a very productive day.
First up was to complete the handbrake installation. I connected the calliper to the pull cable using an M6 bolt and a nylock nut, and then repositioned and adjusted the cable in it’s mounting bracket near the handbrake lever. Ok it’s time to pull the brake on. A quick test shows that it’s having no effect at all…. hmmm. Ok, I’ll adjust the pinch lever and have another go…Hmmm, I can still move the car but the brake disk next to the diff does appear to be locked solid… what’s going on?
A quick inspection shows that the OS drive shaft hadn’t been inserted fully into the diff, and wasn’t engaging with the splines, therefore without both wheels attempting to turn at the same time , the diff was allowing the connected NS wheel to rotate freely even though the diff itself was immobilised by the handbrake. Of course the disconnected OS wheel was rotating freely anyway. Unfortunately despite my best efforts the OS drive shaft refused to inset correctly into the diff. As is usual with drive shafts the CV joints were simply “plunging” rather than transmitting any force to insert the inner joint into the diff. In order to get the joint inserted I had to remove the wheel and disassemble the OS suspension, whereupon the CV joint went in very quickly with a nice satisfying click. The hand brake should now work, but I’ll test it when I’ve finished the next job.
While the car was on the quick lift jack, I thought I’d complete the installation of the rear rear studs to convert from wheel bolts to wheel nuts. This I did without incident and half an hour later the car was on it’s wheels. Time to test the handbrake. Whoo Hoo the wheels move about 3 degrees and then the diff locks up and the car is held on the handbrake. Wonderful a completed system!
No doubt it will need some further adjustment, and the bracket near the handbrake lever is a bit rusty so that’ll need some paint but for all intents and purposes the handbrake mechanism is done. 
. Oh it’ll need a return spring too, but these are just details. 
S
o I bolt up all the Diff mounting bolts and make sure it’s in it’s final position, and nice and solid.
Before I can leave the diff and drive train I need to make a mounting bracket for the Digidash’s speedo sensor. The sensor works by sensing two magnets that are epoxied to a rotating part of the drive train, I elect to fix the magnets to the NS inner CV joint, as this will allow me to fit a mounting bracket to the NS chain tension adjustment plate. As the CV joint and mounting plate are effectively fixed together by the diff this should mean that I shouldn’t have to adjust the speedo sensor when I change the chain tension or alter the final drive ratio by opting for a different chain wheel. The sensor is a threaded nylon rod supported by two nylon nuts and fits an 12mm hole.
So I set about for some sparky fun with Mr Angle grinder and Mr MIG welder and a while later I had fabricated the the required bracket. Here you can see it positioned on the NS diff adjuster. I had to be careful with the positioning to ensure that there is enough room for the both the securing nut, and the sensor magnets between the bracket’s inner face and the CV joint.
I also had to make sure that the sensor will point correctly at the CV joint surface and be in the correct radial orientation.
So here’s a pic of the completed unit, the bracket is now trimmed and welded to the NS diff adjuster plate. The whole unit has been repainted and I’ll fit it to the car tomorrow. Once it’s on the car I can also epoxy the trigger magnets onto the CV Joint.
I actually found making this little bracket very satisfying…. at last I’m starting to actually “build” this car.
So now I turn my attention to coolant pipes. The old pipes had included some steel sections, these had corroded and I had removed them. I had also decided that all my coolant pipes were going to be aluminium just like on the original bike, that way the engine should be protected from corroded steel in the coolant.
So I set about cutting 32mm OD Ali pipe to run from the engine bay to the front of the car, it’s only when I come to start fitting it that I realise that the mounting P Clips I’ve bought for this purpose will not hold the pipe snugly and it will rattle around, despite the fact that I’ve bought 32mm P clips. Hmmm I need to think about this for a while.
While I’m pondering the coolant pipe runs I remember Tim Pell warning me to put air bleed points in all the coolant hoses as he had real problems bleeding the air from the system. What Tim has done on the MK2 Evo is to weld M6 nuts to his steel pipes, drill a hole in the centre and fit a blanking bolt. With aluminium pipes I don’t have this option (as you can’t weld steel nuts to aluminium) but I do have a TIG welder…. so time for some more sparky fun.
By the end of the afternoon I’ve fabricated a couple of Ali pipe runs for the front of the car. The pipes are made from 32mm OD tube for the main pipe and 18mm OD tube for the bleed reservoir. The end of the bleed reservoir is capped with some 4mm Ali plate, this I will drill and tap to take a blanking bolt to act as a bleed valve. The short section of narrow bore pipe will be positioned vertically above the main pipe run. It’s function is to act as a reservoir and catch any bubbles that are circulating with the coolant. Any bubbles should be moving along the roof of the main pipe and should therefore rise up and be caught by the reservoir, where they can be easily bled away.
I’m quite proud of the welding on these, TIG welding is hard, and TIG welding Ali is harder than a very hard thing. So by my standards these are very presentable, and have given me a lot of confidence that I can fabricate the more complex plumbing required in the engine bay. Hopefully tomorrow I can get the plumbing completed at the front and sides of the car.
Actually I think Citroen BXs are fitted with some nice brass bleed bolts, I might just have to use these in my quest to remove any steel from the system.
So there we are quite a successful day, now if only I had some brake callipers, and a dry sump system……….